Pengaruh Pengeringan Terhadap Mutu Nasi Uduk Instan
D R Y IN G E F F E C T S O N IN S T A N T N A SI U D U K Q U A L IT Y
A n to n iu s K u rn ia an d B u d iatm an S atiaw ih ard ja
D ep artm en t o f F o o d S cien ce an d T ec h n o lo g y , F ac u lty o f A g ricu ltu ral T ech n o lo g y , B o g o r A g ricu ltu ral
U n iv ersity , IP B D arm ag a C am p u s, P O B O X 2 2 0 , B o g o r, W e st Ja v a, In d o n esia
P h o n e : + 6 2 8 1 3 1 6 3 3 2 5 2 7 , E - m a i l : a n t o n iu s k u r n ia @ y a h o o .c o m
A B STR A C T
R ice is th e sta p le fo o d fo r m o st o f In d o n esia n . T h e p r o d u ctio n o f rice in c rea se s e ve ry ye a r s. In 2 0 1 0 ,
t h e p r o d u c t i o n o f r i c e w a s a b o u t 6 5 ,9 8 b i l l i o n t o n ,w h i l e c o n s u m t i o n o f r i c e i s 1 3 9 ,5 k g / c a p i t a l / y e a r . B a s e d o n
th ese d a ta , th e d evelo p m e n t o f rice p r o d u ct is a p o ten tia l m a rket. N o w a d a y s m a n y p eo p le d o n o t h a v e m u ch tim e
to p r ep a re th eir fo o d . In sta n t fo o d is co m m o n ly ch o o se d b y th e m o d er n p eo p le . Q u ic k c o o kin g rice m eth o d s
h a ve b ee n co m m o n ly u se d sin c e 1 9 7 0 , b u t th eir p ro d u ct s a re n o t p o p u la r in In d o n e sia . T h e p u rp o s e o f th is
res ea rch is to p ro d u c e a q u ic k co o kin g ric e w ith sp ecia l ta ste n a tive to W e st S u m a te ra e, ca lled “ n a si u d u k ” .
T h e p re p a ra tio n in v o lve s s o a kin g , c o o kin g (g ela tin izin g ) a n d d ryin g u sin g flu id ize d b ed d ry er.T h is re se a rc h w a s
fo cu s ed o n to fin d o u t th e o p tim u m
d ryin g c o n d itio n s o r tr ea tm en t to p ro d u ce th e g o o d q u a lity o f q u ic k c o o kin g
r i c e . T h i s r e s e a r c h u s e d t h r e e d i f f e r e n t d r y i n g t r e a t m e n t s , n a m e l y A ,B , a n d C
co m b in a tio n
of
tim e
and
tem p e ra tu r e
h isto r y . It
w as
fo u n d
th a t
the
trea tm e n t w h ich w e re b a se d o n
o p tim u m
of
d ryin g
m eth o d
w as
th e
A
tra tm en t. In th e A tre a tm en t, th e ric e w a s fr ee zed fo r 2 4 h o u rs a t -2 0 ° C . A fter th a t, ric e w a s d ried fo r 3 0 m in u te s
a t ro o m tem p e ra tu r e a n d th en in cr ea sed th e tem p era tu re stra rt fro m
4 0°C , 60°C , and 80°C
fo r 1 0 m in u te s in
ea ch tem p e ra tu re. T h is m eth o d re su lted in a g o o d a c cep ta n ce f ro m p a n elists.
K eyw o rd s : q u ic k co o kin g ric e, d ryin g , flu id ized b ed d r ye r
ii
A N T O N IU S K U R N IA . F 2 4 0 7 0 0 9 5 .P en g a r u h P en g erin g a n T erh a d a p M u tu N a si U d u k In sta n . D i b aw ah
b im b in g an
D r .I r . B u d i a t m a n S a t i a w i h a r d j a , M .S c . 2 0 1 2 .
R IN G K A SA N
N asi ad ala h m ak an p o k o k b ag i se b ag ia n b e sar m as y arak at In d o n esi a. P ro d u k si b eras b erk em b an g teru s
setiap tah u n . P ad a 2 0 1 0 ,
tah u n .
B erd asarkan
bany ak
oran g
tid ak
d ata
p r o d u k s i b e r a s m e n c a p a i 6 5 , 9 8 j u t a t o n . K o n s u m s i b e r a s a d a l a h 1 3 9 ,5 k g / k a p i t a /
terseb u t,
m em ilik i
pen gem b ang an
w ak tu
cukup
bera s
u n tu k
da pat
m en y ia p k a n
m erupa ka n
pasar
m ak ana n
m ereka.
yan g
m e n j a n j i k a n .S a a t
Pro duk
in sta n
in i
um um ny a
sem a k in b an y ak d ig em ari u n tu k d ik o n s u m si. P ro s es p e n g o la h an n asi in stan m u lai d ik em b an g k an p ad a tah u n
1 9 7 0 , n am u n p ro d u k terseb u t tid ak d ip asark an d i In d o n esia.
T u ju an
d alam
p en elitian
k ali
in i
ad ala h
u n tu k
m e n g h asilk an
produ k
n asi
in sta n ,
d eng an
bum b u
trad isio n al y an g b eras al d ari S u m atra B arat, y an g d ise b u t n a si u d u k . P ersiap an p ro d u k n a si u d u k m elip u ti tah ap
p eren d am an , p em as ak a n , p em b e k u an , d an p en g erin g a n m e n g g u n a k an flu id ized b ed d r yer .
F o k u s p a d a p en elitian in i u n tu k m e n cari k o n d isi p en g erin g an y an g o p tim u m
yang
b aik . P en elitian k ali in i m en g g u n a k an
tig a p erlak u a n p en g erin g an
yang
u n tu k m e n g h asilk an p ro su k
b erb e d a, y aitu A , B , d an
m eru p ak an k o m b in a si d ari w ak tu d an su h u y a n g tep at. M e to d e p en g erin g an y an g o p tim u m
ad alah
m eto d e p en g erin g an A . K o n d isi p e n g erin g an A
m en it p ertam a m en g g u n ak an
p ad a su h u 4 0 ° C
60°C
ad ala h n asi d ik erin g k an
pada
d alam
C
i
p e n elitian in i
su h u ru an g s elam a
30
flu id ized b e d d ry er d en g an sp ee d b lo w er p ad a lev el 9 , selan ju tn y a d ik erin g k an
selam a 1 0 m en it d e n g a n s p ee d b lo w er d itu ru n k an p ad a lev el 7 , lalu s u h u d in aik k an m en jad i
s elam a 1 0 m en it m en g g u n ak a n b lo w er p ad a s p ee d 7 , d alam
1 0 m en it terak h ir su h u d in aik k a n m en jad i
8 0 ° C d en g an sp eed b lo w er lev el 7 . M eto d e p e n g erin g a n A m e n g h asilk an p en erim aan y an g p alin g b aik d ian tara
p erlak u a n lain n y a.
iii
I.
1 .1
PE N D A H U L U A N
L a ta r B e la k a n g
B eras ( O ry za sa tiva ) m eru p ak a n jen is serealia y an g d ijad ik a n m ak an a n p o k o k b a g i p en d u d u k
In d o n e sia.
B erd asark an
A n gka
R am alan
(A R A M )
III-2010
yan g
d ik elu ark an
o le h
B PS
d ik etah u i
b a h w a p r o d u k s i p a d i d i I n d o n e s i a s e b e s a r 6 5 ,9 8 j u t a t o n g a b a h k e r i n g g i l i n g ( G K G ) , n a i k 1 ,5 8 j u t a t o n
( 2 ,4 6 p e r s e n ) d i b a n d i n g p r o d u k s i t a h u n 2 0 0 9
s e b e s a r 6 4 ,4 0 j u t a t o n
y an g tin g g i d iim b an g i d en g a n tin g k at k o n su m si n a si d alam
G K G . K ap a sitas p ro d u k si b era s
n eg eri y an g tin g g i. T in g k at k o n s u m si n asi
d i I n d o n e s i a a d a l a h 1 3 9 ,5 k g / k a p i t a / t a h u n p a d a 2 0 0 9 . T i n g g i n y a k o n s u m s i n a s i d i I n d o n e s i a m e m b u a t
beras
m erupak an
k o m o d ita s
yang
san g at
b erp elu an g
u n tu k
d iek sp lo tiasi
leb ih
la n ju t
d alam
p en g elo laan n y a.
P en g o lah a n
bera s
sa at
in i
um um nya
d io la h
m en jad i
n asi
atau p u n
b eras.
P en g o lah an
bera s
trad isio n al u m u m n y a m em b u tu h k an w ak tu s ek itar 3 0 m e n it. W ak tu terseb u t m eru p a k an w ak tu u n tu k
m en an ak b era s h in g g a m atan g , jik a d itam b ah k an d en g an w ak tu p ersiap an n y a m ak a d ib u tu h k an w ak tu
sek itar
1
jam . T ah ap
p em a sak an
n asi
yan g
p a n jan g
m em b uat
p em a sak an n a si y a n g leb ih p rak tis d en g an m en g g u n a k an
m u d ah d an p ra k tis d alam
s eb a g ian
b esar
orang
rice co o k er. P e n g g u n a an
m em ilih
cara
rice c o o k er leb ih
p em as ak an n a si, m es k ip u n d em ik ian m a sih p erlu cara p em asa k an y an g leb ih
p rak tis d a n sia p d is an tap .
K ece nderun ga n
yang
b erkem b ang
d alam
m a sy a k arat
m od ern
sa at
in i
ad alah
m en g o n su m si
m ak an an in sta n y a n g d a p at d en g a n m u d a h d isiap k an d an d is an tap . T u n tu tan efesien si w ak tu , m em b u at
k o n s u m en u n tu k m em ilih m ak an a n in sta n s eb a g ai p o l a k o n su m si s eh ari -h ari.
P ro d u k m a k an an in stan y an g saat in i b ered ar d i p as aran san g at jaran g y an g m en g g u n ak an b era s
seb ag ai
bahan
dasarnya .
M aka nan
in stan
yang
s elam a
in i
d iju al
m em ilik i
k esan
m en g e n y a n g k an k o n su m en , ta n p a m em b erik an k ep u as an b ag i k o n su m e n . Istilah “ b elu m
b elu m
han ya
u n tu k
m a k an , k alau
m ak an n asi” m em b u at m ak an an in sta n terseb u t h an y a m en ah an lap ar k o n s u m en , d a n k o n su m en
tetap m eras a “ b elu m m a k an ”.
P en g em b a n g a n tek n o lo g i n a si siap s aji su d ah lam a d ik em b a n g k an , n am u n u n tu k p ela k sa n a an n y a
d alam
p as ar In d o n e sia m asih su lit u n tu k m ereb u t h ati k o n su m en . P ro d u k n a si in stan y an g p ern ah a d a
um um ny a
karena
d isajik an
k arak teristik
d alam
n asi
b e n tu k
goreng
n a si
in sta n
g o ren g . N asi
tid ak
sam a
goren g
s ep erti
in stan
n asi
terse b u t
goreng
y ang
su lit
m enem bu s
um um ny a
p a sar,
d ik o n s u m si
m asy arak at.
H asil
o lah an
lain
dari
beras
ad ala h
n asi
u d u k , selam a
in i
n asi
uduk
telah
d ik en al
lu as
o leh
m asy arak at k h u su sn y a d i p u lau Jaw a. M en g k o n su m si n asi u d u k b u k a n lah h al y a n g asin g b ag i se b a g ian
m asy arak at. N a si u d u k in sta n m u n g k in d ap at d iterim a o leh k o n s u m en , seh in g g a d ap at d ik em b a n g k an
leb ih lan ju t d alam
1 .2
sk ala y an g le b ih b esar.
T u ju a n P e n e litia n
P en elitian in i m em p u n y ai tu ju a n u n tu k m en g etah u i p en g aru h p en g erin g a n p ro d u k n a si u d u k
in stan sia p s aji d en g an m en g g u n ak an p en g erin g flu id ized b e d d rye r.
1
II.
2 .1
T IN J A U A N P U S T A K A
S e k ila s T e n ta n g N a s i I n sta n
N asi in stan
ad ala h
d en g an c ara p ersiap an y an g
n asi ce p at m a sak
y an g d a p at d isia p k a n d alam
sed erh an a. N a si in stan m em ilik i
w ak tu 3
sam p ai 5 m e n it
c i ri k h a s d e n g a n b u t i r b e r a sn y a y a n g
d ib u at p o ro u s. S tru k tu r y an g leb ih p o ro u s a k an m em p erc ep at air p an as y an g m asu k k e d al am n y a s aat
d ireh id rasi. S etelah d im a sa k , p ro d u k h aru s se su ai d en g an n asi b ias a d alam
h al rasa, aro m a, d a n tek stu r
(R ew th o n g ,et al, 2 0 1 0 ) . J en is b eras y an g d ig u n ak a n u m u m n y a a d alah b eras d en g an b u lir p an jan g , atau
beras
lo n g
g ra in .
B era s
den gan
b u lir
p an jan g
um um ny a
m em ilik i
b en tu k
d ik erin g k a n k em b ali, k are n a d ap at m en y eru p ai b en tu k b u tir b eras s eb elu m
y ang
leb ih
b aik
saat
d ik erin g k an
T ab el 1 . N ilai N u trisi B eras
Z at G izi
K adar
K arb o h id rat
79%
L em ak
0 .6 6 %
P ro tein
7 .1 3 %
A ir
12%
S u m b er : N u trisi D ata U S D A ,2 0 1 2
N asi in stan d ib u at d e n g a n cara p erlak u an p em as ak a n aw al d an g elatin isasi d en g an m e n g g u n a k an air,
uap
ata u
ga bun gan
k ed uan ya.
G elatin is asi
p ati
d ise b ab k an
o le h
pem ben gka ka n
g ran u la
ak ib at
p em an as an y an g m en y eb a b k a n terjad in y a p en ek a n an g ran u la satu d an la in n y a. P em b en g k ak an g ra n u la
b ersifat reve rsib le, n am u n k etik a m elew ati su h u 6 8 -7 8 ⁰ C
p em b en g k ak an g ran u la b ersifat irre ver sib le
y a n g d i s e b u t g e l a t i n s a s i . S u h u t e r s e b u t d i s e b u t s u h u g e l a t i n i s a s i ( F e n n e m a ,1 9 8 5 ) .
K isaran su h u y an g m e n y eb a b k a n 9 0 % b u tir p ati d alam
air p an a s m em b e n g k ak d an tid ak d a p at
k em b ali p a d a b en tu k as aln y a d ise b u t B irefrin g en t E n d P o in t T em p era tu re atau d is eb u t B E P T . K is aran
beras y ang
ad a d ip a saran m em p u n y ai B E P T
ren d ah (5 5 -6 9 ⁰ C ), m ed iu m
(7 0 -7 4 ⁰ C ), d an tin g g i (7 5 -
7 7 ⁰ C ) ( J u l i a n o ,1 9 7 2 ) . G e l a t i n s a s i p a t i a k a n m e n y e b a b k a n p e r m u k a a n b u t i r b e r a s m e n j a d i r e t a k . B i l a
d im asa k ,
p eng em ba ga nny a
tid ak
se b e sar
p eng em ba gan
p ati
asal.
T ertah a n n y a
p en gem b ang an
in i
d iseb ab k an p em b atas o leh k o m p o n en n o n p ati. G el atin sasi g ran u la p ati m eru p ak an sala h s atu la n g k ah
k u n ci d alam
p em b u ata n n asi cep at s aji. G elatin sa si p ati b ersifat irr eve rsib el, d an m eru p a k an h al y a n g
p en tin g d alam
p ro ses reh id ra si b eras in sta n k erin g y an g terg elatin isasi sem p u rn a u n tu k d isiap k an d an
d ik o n s u m si (W irak artak u s u m ah y a n g d ia cu o leh F ird h au s 2 0 0 3 ) .
N asi in stan d ap at d ib e d ak an m e n jad i b eb erap a tip e b erd a sark a n tin g k at k ad ar air, su h u , w ak tu
p e m a s a k a n a w a l , d a n k o n d i s i p e n g e r i n g a n ( L u h , e t a l ,1 9 8 0 ) . B e r d a s a r k a n p e r l a k u a n i n i d a p a t d i h a s i l k a n
b eb era p a je n is n asi in sta n , y aitu :
1.
U n d e r co o k ed rice y an g m em b u tu h k an w ak tu 1 0 -1 5 m e n it w ak tu p en y ajian
2.
T a ke rice m em b u tu h k an w ak tu 5 m en it u n tu k p ersia p a n
3.
M in u te rice m em b u tu h k a n 1 -2 m en it u n tu k p ersia p an
4.
R ea d y to e a t b r ea kfa st ce re a l d ap at lan g su n g d is a n tap
S elam a
d ip aten k an (L u h
em p at
p u lu h
tah u n
terak h ir
bany ak
m eto d e
p em b u atan
b eras
in sta n
e t a l ,1 9 8 0 ) . M e t o d e y a n g b e r k e m b a n g d a p a t d i k e l o m p o k k a n d a l a m
yan g
telah
1 0 je n is m eto d e
p em b u atan . M eto d e t erseb u t terb ag i d alam :
1.
B eras m u la-m u la d iren d am
d alam
air sam p ai k ad ar air m en jad i 3 0 % . K em u d ian d im as ak
deng an
kadar
air
air
pan as
sam p ai
50 -60
%
den ga n
atau
tan p a
m en ggu nak an
u ap.
K em u d ian p ere b u san atau p e n g u k u san d iteru sk an sam p ai k ad ar airn y a m e n jad i 6 0 -7 0 %
d an k em u d ian d ik erin g k a n d e n g a n h ati-h ati sam p ai k a d ar air 8 -1 4 %
stru k tu rn y a
b erp o ri.
M o d ifik asi
yan g
d ilak u k a n
terh a d ap
c ara
in i
d en g a n m en jag a ag ar
an tara
lain
d eng an
2
p e r l a k u a n p a n a s k e r i n g p e n d a h u l u a n u n t u k m e m b u a t b e r p o r i - p o r i b u t i r - b u ti r b e r a s s e b e l u m
d im asa k d a n d ik erin g k an .
2.
B eras
d iren d am ,
d ireb u s,
d ik u k u s
deng an
tek a n a n
u n tu k
m em bu at
b u tir -b u tir
beras
terg elatin isasi, d k erin g k a n d en g an su h u y a n g re n d a h u n tu k m en g h asilk an b u tir -b u tir b eras
y an g a g ak b erat d an m en g k ilat, k em u d ian d ib eri p erlak u a n d e n g a n p en g em b an g an p a d a
tek an a n d an su h u tin g g i u n tu k m em p ero leh stru k tu r b erp o ri -p o ri y an g d iin g in k an .
3.
B eras d ip re g elatisa si, d ig ilin g atau d itek a n u n tu k m em p ero leh b u tiran y an g ag ak g ep en g
dan
k em u d ian d ik erin g k a n u n tu k m em p ero leh
b u tiran b eras
den gan
k a d ar air 1 2 %
d an
m en g k ilat.
B e r a s d i b e r i p e r l a k u a n d e n g a n u d a r a p a n a s y a n g m e n g a l i r c e p a t p a d a s u h u 6 5 ,6 – 3 1 5 ,6 ˚ C
4.
u n tu k
m em bu at
proses
d ek strin asi
p ati
d alam
b eras,
m em bu at
berp ori -pori
atau
m en g em b an g k a n b u tiran b eras .
5.
B eras d iaro n , k em u d ia n d ib ek u k an , d ith a w in g d an d ik erin g k an .
6.
M eto d e G u n P u ffin g
y ang m erupa kan
k o m b in asi d ari p erlak u a n -p erlak u an p en d ah u lu an
terh ad ap b eras d en g a n p en g g u n aa n s u h u d an te k a n an tin g g i, d iik u ti d en g an p e n g elu aran
sec ara c ep at k e d alam ru an g a n y a n g te k an an n y a le b ih ren d ah .
7.
N asi m a sak d en g a n p e n g erin g an b ek u .
8.
P erlak u a n ata u p em b erian b ah an k im ia.
9.
K o m b in asi 2 ata u leb ih d ari m eto d e d iatas
1 0 .M e t o d e l a i n .
M en u ru t H u b eis (1 9 8 4 ), b eras in stan y a n g d in ilai p alin g b aik m elalu i ta h ap an se b ag ai b erik u t :
perend am an
b eras
dengan
laru tan
N a2H P O
0 ,2
4
%
selam a
18-19
jam
(pH
5 ,2 ) ;
p en etralan
deng an
N a O H 1 N ( p H 7 ,0 - 7 ,3 ) ; p e m a s a k a n s e l a m a 7 m e n i t ; p e n g u k u s a n 1 0 m e n i t ; p e n c u c i a n d a n p e n g e r i n g a n .
B eras
in stan
yang
d ih a silk an
m elalu i
p ro ses
terse b u t
d ap at
d iu b ah
m en ja d i
n a si
m elalu i
p ro se s
r e h i d r a s i . K a d a r a i r b e r a s i n s t a n s e b a g a i p r o d u k a k h i r d a p a t b e r k i s a r 9 - 1 2 ,5 % y a i t u s u a t u k e a d a a n a m a n
sim p an d im a n a n ilai k ad ar air terseb u t d alam
k ead aa n setim b a n g d e n g an k o n d isi lin g k u n g a n n o rm al.
P ati y an g telah m en g alam i g elatin isasi d ap at d ik erin g k an , tetap i m o le k u l-m o lek u l ters eb u t tid ak d ap at
k em b ali lag i k e sifat-sifat asaln y a se b elu m
m en y era p air d alam
air
k em b ali
g elatin isa si. B a h an y an g telah k erin g terseb u t m a sih m am p u
ju m lah y an g b esar. S ifat in ilah y an g d ig u n a k an ag ar b era s in sta n d ap at m en y erap
den gan
m u da h,
y aitu
d eng an
m e ngg una kan
p ati
yan g
telah
m e n g alam i
g elatin isasi
(W in arn o , 1 9 8 4 ).
2 .2 .
T a h a p P em b u a ta n N a si In sta n
T aha p
p em b u atan
p eren d am an d alam
d alam
air
d in g in
n asi
p eren d am an d alam
4
0 .2 %
dap at
d ilak u k an
dengan
be berap a
cara,
d ia n taran y a
ad alah
laru tan k im ia, p em b ek u an , d an p e n g erin g a n . P ad a d a sarn y a p ati y a n g d im as u k k an
aka n
m en yerap
d iserap terb atas d an h a n y a 2 6 %
N a2 H P O
in sta n
air
dan
aka n
terjad i
peng em ba ng an
p ati. T eta p i
ju m lah
air
yang
d ari b erat aw al. U n tu k m en in g k atk an d a y a s erap air p erlu d ilak u k an
laru tan k im ia. M en u ru t H u b eis (1 9 8 4 ), p ere n d am an d ap at d ilak u k an d alam
selam a 1 8 jam . G aram
n atriu m
laru tan
fo sfat ak an m en g a k ib atk a n stru k tu r fisik b eras p as ca
tan ak le b ih p o ro u s, h al in i m en y eb a b k a n p en y erap an
air ak an
leb ih
cep at pa da
w a k tu
peren dam an
m au p u n reh id rasi. P en am b ah an fo sfat s eb a g ai se n y a w a y an g m e n g io n p ad a p ro d u k y a n g b erasal d ari
p ati ak an m en y eb ab k an g ran u l a p ati tah an terh ad a p retro g rad asi selam a p en d in g in an d an p e n in g k atan
su h u s etelah p en d in g in an .
T ah a p p em b u at an b erik u tn y a ad ala h p em b e k u a n . P ro ses p em b ek u an d a n p e n y im p a n an b e k u
ak an m e n in g k atk an p en g em b a n g a n m o le k u l p ati. P em b e k u a n a k a n m ele p a sk a n air y an g terd a p at d alam
sistem
g el.
P ro se s
in i
d ilak u k a n
u n tu k
m en g h a silk an
sifat
p o ro sitas
y ang
tin g g i
s eh in g g a
w ak tu
reh id rasi m en jad i sem ak in sin g k at.
N asi in stan d a p at m en y erap air p an as d en g an ce p at se h in g a d ap at d ik o n s u m si d alam
b ebera pa
m en it. N asi in stan d ap at terb en tu k b ila p o ri -p o ri b eras terb u k a leb ar s eh in g g a m em u d a h k a n reh id rasi
dan
d ip ero le h
lam b at s eb elu m
w ak tu
reh id rasi
y an g
sin g k at, cara
n asi d ik erin g k a n . P em b ek u an
yang
dap at
d ilak u k a n
ad alah
den ga n
pem b eku an
lam b at y a n g m en g h a silk an k ristal es y an g b esar ak an
3
m em b u at ro n g g a p o ri y an g b e sar u n tu k d ih id rasi d en g an c ep at, seh in g g a u k u ra n b era s m e n jad i leb ih
besar.
P em be kua n p ada
su h u
0
-20
C
selam a
20
jam
m en g h a silk an
stru k tu r
k ristal es y an g
b e sar,
p ro se s in i m em e cah k an stru k tu r k o lo id p ati d a n m e n g h asilk a n stru k tu r k ern el y a n g p o ro u s (R ew th o n g
et al, 2 0 1 0 ) . P ro d u k y an g d ih a silk an d ap at d e n g a n c ep at m e n y era p a ir p a d a p em a sa k an k em b ali.
T aha pan
s elan ju tn y a
dari
p em b u ata n
n asi
in stan
ad alah
p e n g erin g an .
P e n g erin g an
ad alah
m eto d e u n tu k m en g aw etk an b a h an p an g an . T u ju an p en g erin g an a d alah m e n g u ra n g i k ad ar air b ah an
sam p ai
m endap at
b io lo g is
dan
kadar
k im ia
air
terten tu
se b elu m
b aha n
yang
dap at
d io lah
m engh am bat
ata u
laju
d im an fa atk an .
k eru sa k an
b aha n
P en guran gan
ak ib at
kad ar
air,
ak tiv itas
m em buat
k o m p o n en zat g izi p ad a k o n s en trasi y an g le b ih tin g g i.
P en g erin g an
adalah
su atu
p eristiw a
p erp in d ah an
m as sa
dan
energi
yan g
terjad i
d alam
p em isa h an air ata u k elem b a b an d ari su atu b ah a n sam p ai b atas k a n d u n g a n air y an g d iten tu k an d en g an
m engg una kan
udara
seb ag ai
flu id a
su m b er
pa nas
dan
p en erim a
uap
c airan
(T rey b al,
1 981).
P en g erin g an m a k an an m em ilik i d u a tu ju an u tam a. T u ju a n p e rtam a ad alah s eb a g ai saran a p en g aw etan
m akan an.
b ertah an
M ik ro o rg a n ism e
h id u p
p ada
y ang
m e n g a k ib atk a n
lin g k u n g a n
d eng an
k eru sak an
kad ar
air
yang
m a kan an
re nda h.
tid ak
S elain
d apat
itu ,
berk em ba ng
b any ak
en zim
d an
yang
m en g a k ib atk a n p eru b ah an k im ia p ad a m ak a n an tid a k d ap at b erfu n g si tan p a k eh ad iran air (G ean k o p lis,
1 9 9 5 ). T u ju an
yang
telah
ked ua
ad ala h u n tu k m em in im alk a n b ia y a d i strib u si b ah an m a k an an
d ik erin g k a n
ak an
m em ilik i
berat
yang
leb ih
rend ah
dan
ukura n
karen a m ak an an
yan g
leb ih
k ecil .
P en g erin g an m e ru p a k a n o p erasi y an g ru m it y an g m elip u ti p erp in d ah a n p an a s d an m as sa se cara tran sien
serta b eb era p a laju p ro se s, sep erti tran sfo rm asi fisik ata u
k im ia, y an g d ap at m en y eb ab k an p eru b ah an
m u tu h a sil m au p u n m ek an ism e p erp in d ah an p an as d an m as sa. P eru b ah a n fis ik y a n g m u n g k in terjad i
m elip u ti : p en g k eru tan , p en g g u m p u lan , k ristalisasi, tran sisi g elas. p a d a b eb erap a k a su s, d ap at terjad i
reak si
k im ia
atau
b io k im ia
yan g
d iin g in k a n
ata u
tid ak
d iin g in k an ,
yang
m en yeb abk an
perub ah an
w arn a, tek stu r, aro m a atau sifat lai n p ad atan y an g d ih asilk a n . P e n g erin g a n terjad i m elalu i p en g u ap an
cairan d en g an p em b erian p a n a s k e b a h an u m p an b as ah
P ad a u m u m n y a zat p ad at selalu m en g an d u n g se d ik it frak si air seb a g ai air terik at. Z at p ad at
y an g ak a n d ik erin g k an b ias an y a terd ap at d alam
b en tu k serp ih (flak e), b ijian (g ran u le), k ristal (cry stal),
serb u k (p o w d er), lem p e n g (sla b ), atau lem b aran
berbed a
satu
sam a lain . Z at c air y an g
a kan
sin am b u n g (co n tin o u s sh eet) d en g a n sifat -sifat y an g
d iu ap k an m u n g k in terd ap at p ad a
sep erti p ad a k ristal; d ap at p u la s elu ru h zat c air terd ap at d i d alam
perm u kaa n z at p adat
zat p ad at sep erti p ad a p em is ah an
p elaru t d ari lem b ara n p o lim er; atau d ap at p u la seb ag ian z at cair s eb a g ian d i lu ar d an seb ag ian d i d alam .
U m p an p en g erin g m u n g k in b eru p a zat cair d i m an a zat p ad at m ela y an g s eb ag ai p artik el, atau d ap at
p u la b erb en tu k laru tan . H a sil p en g erin g an a d a y an g tah a n terh ad ap
b erad a d alam
su h u
ren dah
lin g k u n g a n y an g sa n g at p a n a s, ad a p u la
ata u
p ad at d i d alam
sed an g . P erb ed aan
p en g erin g
p en a n g a n an m ek a n ik k a sar d an
y an g m em erlu k an p en a n g a n an
teru tam a
terletak
d alam
hal
cara
h ati-h ati p ad a
m em in d ah k an
zat
zo n a p en g erin g d a n d alam p ro s es p erp in d ah a n k alo rn y a.
P ro se s p e n g erin g an m e n g h asilk a n stru k tu r p o ro u s y an g ak an m em u d ah k an air u n tu k d ap at
m eresa p k e
d alam
b eras
sa at reh i d rasi. S u h u
o p tim u m
p e n g erin g a n n asi in sta n
m en u ru t R ew th o n g ,
2 0 1 0 a d alah 8 0 ° C . S em e n tara m en u ru t Ja d in g et al, 2 0 1 1 , su h u u n tu k m en g erin g k an g ran u la b erk isar
an tara 6 0 – 7 0 ° C .
2 .3 .
F lu id iz e d B e d D r y e r
T ek n o lo g i F lu id ized b ed d r yer m eru p a k an sala h satu altern atif p ilih an tek n o lo g i p en g erin g a n ,
karena
te k n o lo g i
k o n v en sio n al
produk
de ng an
kom pak,
in i
lain n y a,
m em ilik i
p erp in d ah an
se h in g g a
k ap a sitas
kan dun gan
dengan
in v e stasi
air
yan g
aw al
serag am
relatif
pan as
dan
p en g erin g an
m as sa
da pat
le b ih
leb ih
b aik
b e sar
(S ireg ar, 2 0 0 6 ). T ek n o lo g i
rendah
dan
um um n ya
tek n o lo g i
dari
d an
flu id ized
in i
jen is
d ap at
bed
d ip ak ai
p e n g erin g an
m en g h a silk an
drye r
u n tu k
cuk up
prod uk
b erb en tu k g ra n u lar (M u ju m d ar A S d a n D ev a h a stin S , 2 0 0 3 ). P e n g erin g an m en g g u n ak a n flu id ized b ed
d ry er m em ilik i b eb erap a k eu n tu n g a n , d ia n taran y a :
a.
L aju p en g erin g an tin g g i, k aren a p er s en tu h an an tara p artik el d an u d ara y a n g terjad i sa n g at b aik
b.
L u as p erm u k aa n b a h a n y a n g b erse n tu h a n d en g an aliran u d ara le b ih b esar
c.
E fisien si p a n as tin g g i k are n a k o efisien laju p in d ah p an as d an p in d a h m a ss a m em b es ar
d an m en y eb a b k a n tin g g in y a laju p in d ah p a n a s d a n m a ss a.
4
d.
B iay a in v esta si d a n p em elih araan relatif leb ih ren d ah
P rin sip k erja p ad a alat flu id ized b ed d r ye r d en g an m en iu p k an u d ara p a n a s d ari b ag ian b aw ah
bed.
U dara
pa nas
terse b u t
a kan
m en arik
air
yan g
ada
pada
bah an
u n tu k
k elu ar, s eh in g g a
terjad i
b u b b lin g d a n m e n g a n g k at p ro d u k y an g ad a d iat as b ed . T in g k at b u b b lin g y an g terjad i terg a n tu n g p a d a
besaran
ud ara
yan g
d itu p k a n
( S i r e g a r ,2 0 0 6 ) .
P rin sip
flu id ized
k erja
bed
drye r
dap at
d ilih at
pada
G am bar 1
P lat p erfo rasi
U dara
U dara
U dara
U dara
U dara
U dara
1
2
3
4
5
6
P artik el d alam
p artik el m u lai
P artik el
flu id isasi
flu id isasi
tran sp o rt
k ead aa n d iam
terflu id isasi
terflu id isasi
terb aik
d alam
p n eu m atik
k o n d isi
pada ba han
b erleb ih an
k erin g
G am b ar 1 . P rin sip k erja flu id ized b ed d ry er
F lu id ized b ed d r yer terb ag i ata s b eb erap a b ag ia n , y aitu :
a. B lo w er
B lo w er b erfu n g si u n tu k m e n g h asilk a n aliran u d ata y a n g ak an d ig u n ak a n p ad a p ro s es flu id isasi.
K ip as ju g a b erfu n g si se b ag ai p e n g h em b u s u d ara p an a s k e d alam
ru ang
p en g erin g d an u n tu k
m en g a n g k at b a h an ag ar p ro se s flu id isa si terjad i.
b . E lem en P em an as
E lem en p em a n a s b erfu n g si u n tu k m em a n as k an u d ara h in g g a k elem b a b an relatif u d ara p en g erin g
tu ru n , d an
k alo r
y ang
d ih asilk a n
d ib aw a
o le h
aliran
ud ara
y ang
m elew ati
elem e n
pem ana s
seh in g g a p ro se s p en g u a p an air d ari d alam b ah an d ap at b erlan g su n g .
c. H oppe r
H opper
b erfu n g si se b ag ai tem p at m em asu k k an b ah a n y an g ak an d ik erin g k a n k eru an g p e n g erin g
d . T h er m o c o u p le
T h er m o c o p u le b erfu n g si se b ag ai p e n g u k u r tem p eratu r u d ara m asu k d an u d ara k elu ar.
P en g erin g an m en g g u n ak an F lu id ized b e d d ry er d a p at d ig u n a k an u n tu k m e n g erin g k an g ran u la.
P en g erin g an
m e ngg una kan
F lu id iz ed
b ed
d rye r
m am p u
m em p ertah an k an
k o m p o sisi
k im ia
dan
m e m p e r b a i k i s i f a t f i s i k o k i m i a p a t i s a g u k e r i n g ( J a d i n g e t a l ,2 0 1 1 ) . K e m a m p u a n u n t u k m e n g e r i n g k a n
g ran u la
in i
d iseb ab k an
kem am pu an
alat
u n tu k
m enc apai
p ro ses
flu id isa si
yang
o p tim al
seh in g g a
m am p u m e n c ap ai w ak tu p en g erin g an y a n g sin g k at.
5
a. G ran u la p ati b as ah
b . G ran u la p ati h asil
c. G ran u la
p ati
p en g erin g an
p en g erin g an
m en g g u n a k an F lu id ize d
k o n v en sio n al
h a sil
b ed d ry er
S u m b e r : J a d i n g e t a l ,2 0 1 1
G am b ar 2 . B en tu k g ran u la p ati
6
III.
3 .1
B A H A N D A N M E T O D E
B a h a n d a n A la t
B ah a n u tam a y an g d ig u n a k an d i d alam
p en elitian in i ad alah b eras s erta b u m b u n a si u d u k y a n g
m elip u ti sereh , d a u n jeru k , s an tan , d an g aram . B era s y a n g d ig u n a k an d alam
p era v arietas IR
ad alah
4 2 d an b eras p u l en v arietas IR
64
p e n elitian in i ad alah b era s
d en g an p erb an d in g a n 2 :1 . A lat y an g d ig u n ak an
f l u i d i z e d b e d d r y e r ,p a n c i , d a n d a n g , k o m p o r , t i m b a n g a n a n a l i t i k , g e l a s p e n g a d u k , t e r m o m e t e r ,
w a terb a th , g elas u k u r, c aw an
alu m u n iu m , g ela s p iala, d a n alat g ela s lain u n tu k
a n alisis p ro k sim at.
K o m p o si si b ah an m em b u at n a si u d u k d ap at d ilih at p ad a T ab el 2 .
T ab el 2 . K o m p o sisi b ah an n asi u d u k
B aha n
K o m p o s is i
B eras
500 g
A ir
600 m l
S an tan
20 m l
P en y ed a p (ro y co sa p i)
2 g
G aram
8 g
S ereh
10 g
D au n S alam
5 g
G a m b a r 3 .B a h a n m e m b u a t n a s i u d u k
S p esifik asi :
M odel N o. A P S . 6
S e r i a l N o .: A P S - B 1 4 2 6
E C t y p e - a p p r o v a l N o .: T 6 1 2 6
T e s t C e r t i f i c a t e N p .: T C 6 1 0 1
M F D B y : U W E C o ., L td .
G am b ar 4 . T im b an g an
S p esifik asi :
T y p e : F lu id B ed D ry er
M odel N o. M K II
S e r i a l N o .: F N D / 2 4 0 / 9 1 / 5 7 4 2
M ad e b y : A rm field
G am b ar 5 . F lu d ize d B ed D rye r
7
3 .2
M e t o d e P e n e l it i a n
M eto d e p en elitian y an g d ig u n a k an d alam p en elitian in i terd iri d ari p en elitian p en d ah u lu an d an
p en elitian u tam a . B erd a sark a n p en elitan terd ah u lu o l eh F ird h a u s ( 2 0 0 3 ), telah d iteliti ten tan g m eto d e
p en g erin g an n asi in stan b eru p a p en g aru h p ere n d am an d alam
perend am an
d alam
laru tan
k im ia,
m en g h asilk a n n asi in sta n y an g
N a2H P O
4
b aik .
m eto d e
pem asaka n
P a d a ta h ap
laru tan N atriu m
ju g a
p erlu
F o sfat. S elain p en g aru h
d ip erb aik i
d alam
p e n d a h u lu a n d ilak u k a n p eren d am an
k aitan n y a
d alam
laru tan
seb e sar 0 ,2 % s elam a 1 2 0 m en it. P a d a p em a sa k an d ig u n ak an reto rt u n tu k m em a sak n a si u d u k
(G am b ar 6 ). P ad a tah a p p e n d a h u lu a n ju g a
d ilak u k an p em a sak an m e n g g u n a k an m eto d e
aron k uku s .
P em as ak an n asi u d u k m en g g u n ak an reto rt d en g an m en g g u n ak an s u h u 1 2 1 ˚C , d e n g a n 3 ren ta n g w ak tu
yang
b erb e d a y aitu 5 , 1 0 , d an 1 5 m en it. S etelah b eras m ata n g k em u d ia n d ico b a u n tu k d i b ek u k a n .
P em b e k u a n b eras d ila k u k an s elam a
d ib u at p a d a tah ap
p en d ah u lu an
2 4 jam
pad a suhu
ad ala h 6 0 ° C
dan
-20˚C
p a d a freez er. S u h u p en g erin g an
8 0 ° C . P en g am atan
yang
y an g d ilak u k an terh ad a p tah ap
p en d ah u lu an ad ala h p en g am atan se cara v isu al h a sil p en g erin g an .
B eras
P en c u cian
P eren d am an selam a 1 2 0 m e n it + N a 2H P O
4
0 ,2 %
P em as ak an d alam
P em as ak an d alam
P em as ak an d alam
reto rt selam a 5 m en it +
reto rt selam a 1 0 m en it
reto rt selam a 1 5 m en it
penam bah an bum b u
+ pe nam b aha n b um bu
+ pe nam b aha n b um bu
P en g aro n a n s elam a 1 0
m en it + b u m b u
P en g u k u sa n s elam a
3 0 m e n it
P em b e k u a n s elam a 2 4 jam
P en g erin g an
P en g erin g an
su h u 6 0 ° C
su h u 8 0 ° C
N asi U d u k
In sta n
G am b ar 6 . S k em a P em b u atan N asi U d u k In sta n tah ap p en elitian p en d ah u lu an
S etelah m em p ero leh d ata p en g am atan h asil p e n elitian p e n d a h u lu a n (lih at p ad a B ab H asil d an
P em b a h a san ), d ilak u k a n p e n elitian u tam a s ep erti terlih at p ad a G am b ar 7 . P ro s ed u r in i b erfo k u s p a d a
p erlak u a n p en g erin g an y an g d id u g a ak an p alin g b erp en g aru h terh ad a p p ro d u k
8
B eras
P en c u cian
P eren d am an selam a 1 2 0 m e n it + N a 2H P O
4
0 ,2 %
P en g aro n a n s elam a 1 0 m e n it + p e n am b ah an b u m b u
P en g u k u sa n s elam a 3 0 m e n it
P em b e k u a n ( free zin g ) s elam a 2 4 jam
P erlak u a n p en g erin g an A
P erlak u a n p en g erin g an
N asi U d u k
G am bar
A
yang
P erlak u a n p en g erin g an C
In sta n
7 . S k em a P em b u atan N asi U d u k In stan tah ap p en elitian u tam a
P erlak u a n p en g erin g an
p en g erin g an
B
d im ak su d
y a n g d ig u n ak an p ad a p en elitian u tam a
ad ala h
n a si
yang
tela h
y aitu A , B
d ib ek u k an , d ik erin g k a n
d an C . P erlak u an
pad a
F lu id ized
B ed
D rye r p ad a su h u k am ar d an k e cep atan b lo w er d is et p ad a lev el 9 selam a 3 0 m en it p ertam a. S elan ju tn y a
su h u d in aik k an m en ja d i 4 0 ˚C
selam a
1 0 m en it d a n k ece p atan
b lo w er d itu ru n k an
p a d a le v el 7 . S u h u
b lo w er selan ju tn y a d in aik k an m e n jad i 6 0 ˚C selam a 1 0 m en it d an k ec ep ata n b lo w e r tetap
P ad a 1 0 m en it terk ah ir su h u d in aik k a n m e n jad i 8 0 ˚C d en g an k e cep atan b lo w e r
P erlak u a n p e n g erin g a n B
p ad a lev el 7 .
tetap p a d a lev el 7 .
p a d a p en elitian in i d ilak u k a n d en g a n p erlak u an
p en g erin g an
n asi
y an g telah d ib e k u k an p ad a F lu id iz ed B ed D r ye r d en g an su h u k am ar d a n lev el k e ce p atan b lo w er p a d a
lev el 9 selam a 3 0 m e n it. S etela h itu F lu id iz ed B ed D ry er d in aik k an m en ja d i 6 0 ˚C
d itu ru n k an m en jad i lev el 7
p en g erin g an
k ec ep ata n
n asi
b lo w er
selam a
3 0 m en it. P erlak u an
yan g
telah
d ib ek u k an
pad a
lev el
9
selam a
p ada
30
F lu id iz ed
p en g erin g a n C
B ed
m en it. K em u d ian
d alam
D rye r
den gan
su h u
F lu id iz ed
d a n lev el b lo w e r
p en elitian in i ad alah
suhu
k am ar
dan
B ed
D ry er
d in aik k an
lev el
m en jad i 8 0 ˚C serta k ece p ata n b lo w e r d itu ru n k an p a d a lev el 7 selam a 3 0 m en it.
P ro se s reh id rasi n a si u d u k in stan d ilak u k an d en g an m e n aru h b eras d alam
gram
d a n air d en g an su h u 9 0 ° C
g ela s se b an y ak 2 0
se b a n y a k 1 5 0 m l d an d iam k an selam a 5 m e n it (G am b ar 9 ). A n alisis
y an g d ilak u k a n ad al ah rasio reh id rasi, p o ro sitas, o rg a n o lep tik serta p ro k sim at u n tu k h a sil terb aik . U ji
o rg an o le p tik terh ad ap n asi in sta n k erin g y an g tela h d ireh id rasi d e n g a n m en g g u n ak an u ji h ed o n ik sk ala
9
tu ju h . A n alisis o rg a n o lep tik in i m en g g u n ak a n u ji ratin g h ed o n ik m en g g u n ak an 3 0 p an elis y an g tid ak
terlatih . T ah ap p ertam a an alisis m en g g u n ak a n A N O V A u n tu k m en g eta h u i p en g aru h tah ap a n p erlak u an
p en g erin g an
pada
taraf
sig n ifik an si
5
% .
S etela h
d ik eta h u i
terd a p at
p erbed aan
sig n ifik an
d ian tara
k etig a p erlak u an , k em u d ian d ilak u k an u ji lan ju t y an g b eru p a u ji D u n can u n tu k m en g et ah u i sam p el d ari
p erlak u a n m a n a y a n g b erb e d a d ari tiap p erlak u a n . S etelah d id a p atk a n n asi in stan d e n g a n n ilai u ji ratin g
h ed o n ik y an g tertin g g i, m ak a d ilan ju tk an d e n g a n a n alisis p ro k sim at terh ad ap n asi in stan ters eb u t.
2 0 g N asi u d u k in stan
1 5 0 m l air d e n g a n s u h u
90 °C
T aru h d alam g elas tertu tu p d an tu n g g u s am p ai 5 m en it
N asi u d u k in stan siap d i san ta p
G am b ar 8 . S k em a reh id ra si n a si u d u k in sta n
3 .3
A n a lisis P r o d u k
3 .3 .1 .
R a sio R e h id ra si
C o n to h
seb any ak
10
gram
d im asu k k a n
ke
d alam
g ela s
p iala,
d itam b ah
dengan
15 0
m l
o
aq u a d e s. C o n to h k em u d ia n d im as u k k an k e w a te rb a th b ersu h u 8 0 C selam a 1 0 m en it. H asil p em as ak an
d ib iark an sam p ai m e n ca p ai su h u k am ar, k em u d ian d itim b an g b erat n asi y an g tela h d ireh id ra si s etelah
d i t i ri sk a n . R a si o r e h i d r a si ( R r ) d i h i t u n g d e n g a n r u m u s :
B erat n asi in stan setelah reh id rasi (g )
R r
=
B erat co n to h n a si in sta n (g )
3 .3 .2 .
R o n g g a K o so n g ( V o id S p a c e)
V o id sp a ce
in stan
ad ala h b e sarn y a ru an g
d im asu k k a n k e d alam
kosong
antar beras
d alam
w a d ah . B u tiran -b u tiran b eras
g ela s u k u r 2 5 m l sam p ai p e n u h , k em u d ia n d itam b ah k an to lu en s am p ai
b u tiran terseb u t tere n d am lalu d iu k u r v o lu m e to lu en y an g d ib u tu h k a n .
�
3 .3 .3 .
=
�
100%
�
U ji O rg a n o lep tik
N
= vo id sp a ce
V c
= v o lu m e cairan
V
= v o lu m e to tal
( A d a w iy a h D R d a n W a y sim a . 2 0 0 9 )
U ji o rg an o lep tik y an g d ilak u k an ad ala h u ji p en erim aan terh ad ap w arn a, aro m a, tek stu r, ra sa
d an citra k es elu ru h a n d im an a s etiap p a n elis d ih aru s k a n m en g em u k ak a n tan g g ap an p rib ad in y a terh ad ap
10
produk
yang
d isajik a n . U ji
p en erim aan
yan g
d ilak u k a n
ad alah
u ji h e d o n ik
yang
m en g g u n a k an 3 0 p an elis tid ak terlatih . S k ala h e d o n ic y an g d ig u n ak an ad alah 1
7=
S a n g at S u k a ; 6 = S u k a; 5 = A g a k S u k a; 4 = N etral; 3 = A g ak
T id ak
–
d ilak u k an
d eng an
7, di m an a ang ka
S u k a; 2 = T id ak S u k a; 1 = S a n g at
T id ak S u k a
3 .3 .4 .
K a d a r A ir
(SN I 01-39 45-199 5)
P en g u k u ra n d ilak u k an d e n g a n m en g g u n ak a n m eto d e o v en . C aw an k o so n g d ik erin g k a n d alam
o v en s elam a 1 5 m e n it d an d id in g in k a n d alam
y an g tela h d ik erin g k an d im as u k k an d alam
o
oven pad a suhu 105 C
ke
d e sik ato r, k em u d ia n d itim b an g . S e b an y ak 5 g ram
co n to h
ca w an y an g telah d itim b an g s elan ju tn y a d ik erin g k an d alam
selam a 6 jam , c aw an y a n g telah b erisi co n to h terse b u t sel an ju tn y a d ip in d ah k an
d esik ato r, d id in g in k an ,
dan
d itim b an g . P en g erin g an
d ilak u k an
sam p ai
d ip ero leh
berat
k o n sta n ,
k em u d ia n d ih itu n g b erd asark an k eh ilan g an b erat y aitu selisih b erat aw al d ik u ran g i b erat ak h ir.
�
�
�
�� ( %
�
��
%
−
) =
�
=
−
− (
−
∗ 100%
)
∗ 100%
−
a = B erat caw an k o s o n g k erin g ( g )
x = B erat sam p el aw al (g )
y = B erat caw an + sam p el k erin g
x = B erat sam p el b a sa h
K adar A bu ( SN I 01 – 3 945 – 1 995 )
3 .3 .5 .
C o n to h b era s d itim b an g s eb a n y a k 2 -3 g ram
k e d alam
caw an p o r selen y an g telah d ik etah u i
b o b o tn y a. A ra n g k an d i ata s n y ala p em b a k ar, lalu a b u k an d alam
o
550 C
tan u r listrik p ad a
su h u m a k sim u m
sam p ai p en g ab u an seles ai (sek ali - sek ali p in tu tan u r d ib u k a se d ik it ag ar o k sig e n b is a m a su k ).
D in g in k an d alam
d e sik ato r lalu d itim b an g h in g g a b o b o t tetap .
K adar a bu (% ) = x – a x 10 0%
w
a
= B erat caw an k o s o n g k erin g (g )
w = B erat s am p le aw al (g )
x = B erat abu + b erat caw an
3 .3 .6 .
K a d a r P ro tein d en g a n M eto d e K je ld a h l
S eba nya k
selen iu m
0 .2 5
0 .2 5 g r a m
gram
dan 3 m l H
sam p le,
2
SO
4
d im a su k k an
d alam
lab u
K jeld ah l
m l
dan
tam b ah k an
p ek at. K em u d ia n lak u k an d estru k si (p em an asa n d alam
m e n d i d i h ) s e l a m a 1 j a m , s a m p a i l a r u t a n j e r n i h .s e t e l a h d i n g i n t a m b a h k a n
N a O H 4 0 % ,l a l u d i d e s t i l a s i . H a s i l d e s t i l a s i d i t a m p u n g d a l a m
m l H 3B O 3 2%
100
d an 2 tetes in d icato r B ro m
kea da an
5 0 m l aq u ad est d a n 2 0 m l
lab u E rlen m ey er y an g b erisi cam p u ran 1 0
C re so l G re en -M eth yl R ed
b erw arn a m era h m u d a. S etelah
v o l u m e h a s i l t a m p u n g a n ( d e s t i l a t ) m e n j a d i 1 0 m l d a n b e r w a r n a h i j a u k e b i r u a n ,d e s t i l a s i d i h e n t i k a n d a n
d estilasi d ititrasi d en g an H C L 0 ,1 N
sam p ai b erw arn a m era h m u d a. P erlak u an y an g s am a d ilak u k an
ju g a terh ad ap b lan k o . D e n g an m eto d e in i d ip ero leh k ad ar N itro g en to tal y an g d ih itu n g d e n g a n ru m u s:
% N = (m l H C l – m l b lan k o ) x n o rm alitas x 1 4 x 1 0 0
m g sam p el
% P r o t e i n = % N x 6 ,2 5
3 .3 .7 .
K a d a r L em a k d e n g a n M eto d e S o x h let
S eba nya k
2
gram
sam pel
d ise b ar
di
atas
kapas
y an g
b eralas
k ertas
s arin g
d an
d ig u lu n g
m em b en tu k th im b le, lalu d im as u k k an k e d alam la b u so x h let. K em u d ian ek strak si selam a 6 jam , d en g an
11
p e l a r u t l e m a k b e r u p a h e k s a n s e b a n y a k 1 5 0 m l .L e m a k y a n g t e r e k s t r a k , k e m u d i a n d i k e r i n g k a n d a l a m
o v en p a d a su h u 1 0 0
0
C s elam a 1 jam .
% lem ak = B erat lem ak x 1 0 0
B erat co n to h
B erat lem ak = (b erat lab u + lem a k ) – b erat lab u
3 .3 .8 .
W a k tu R eh id r a si
S am p el y an g d ian g g a p terb aik d iam b il se b an y a k 2 0 g d itim b an g d an d ic am p u r d en g an 6 0 m l
air p ad a s u h u 9 0 ° C
teren d am
d i d alam
g ela s p iala 2 5 0 m l. W ak tu reh id ra si d iu k u r m u lai seja k s elu ru h s am p el
air p an a s s am p ai air terserap s em u a.
12
IV .
4 .1
H A S IL D A N P E M B A H A S A N
P e n e l i ti a n P e n d a h u l u a n
H asil d ari p en elitian p en d a h u lu a n
m en u n ju k k an b a h w a p erlak u an p em as ak an m en g g u n ak an
reto rt selam a 5 m en it m en g h a silk an n asi y an g k eras d an k u ran g m as ak . P em a sak an selam a 1 5 m e n it
m en g h asilk a n n asi y an g h an cu r a k ib at terlalu m a sa k . A d ap u n p em a sa k an d e n g an reto rt s elam a 1 0 leb ih
k u ran g s eta ra d alam p en am p a k an v is u al d en g an aro n k u k u s , k aren a itu h asil p em as ak an reto rt s elam a 5
d an 1 5 m e n it tid ak d ik erin g k an
d a n p erb an d in g an h a siln y a d ap at d ilih at p ad a T a b el 3 .
T ab el 3 . K arak teristik n asi h asil p em asa k a n d a n p en g erin g an
P erlak u a n
P en g am atan v isu al p ro d u k
1
L en g k et, tid ak b isa m en jad i b u tiran tu n g g al, b erw arn a a g ak k e co k lata n
2
L en g k et, tid ak b isa m en jad i b u tiran tu n g g al, b erw arn a k eco k latan
3
T id ak len g k et, b isa m en jad i b u tiran tu n g g al, b erw arn a a g ak k e co k lata n
4
T id ak len g k et, b isa m en jad i b u tiran tu n g g al, b erw arn a k eco k latan
K eteran g a n :
p erlak u a n 1 : b eras d im as ak m e n g g u n ak a n reto rt selam a 1 0 m en it d an d ik erin g k an p ad a s u h u 6 0 ° C
p erlak u a n 2 : b eras d im as ak m e n g g u n ak a n reto rt selam a 1 0 m en it d an d ik erin g k an p ad a s u h u 8 0 ° C
p erlak u a n 3 : b eras d im as ak m e n g g u n ak a n m eto d e aro n k u k u s d a n d ik erin g k an p a d a su h u 6 0 ° C
p erlak u a n 4 : b eras d im as ak m e n g g u n ak a n m eto d e aro n k u k u s d a n d ik erin g k an p a d a su h u 8 0 ° C
P em as ak an m en g g u n ak an reto rt m e n g h asilk a n b eras y a n g len g k et, seh in g g a s aat d ik erin g k an
m en g g u n a k an flu id ized b ed d r yer m e n g h asilk an b u tiran b era s y an g tid a k d ap at terp isah k aren a len g k et.
N asi
yang
le n g k et
terseb u t
d iseb ab k an
o leh
b eras
yan g
terg elatin isa si.
B era s
y ang
d im as ak
m en g g u n a k an reto rt m en g alam i g elatin isa si p ati y an g b erleb ih a n , k are n a tek an a n p a d a saat p em as ak an
terlalu
b esar
G elatin isasi
d an
pad a
m eny eb abk an
bera s
yan g
stru k tu r
d im as ak
sel
b eras
m en jad i
m en ggu nak a n
reto rt
rusak
dan
m en g ak ib atk an
m enyeb abk an
terjad in y a
len g k et .
p em asak an
b erleb ih an (o ve r c o o k ed ) .
B erd as ark an d ata ters eb u t, m ak a d ip ilih m eto d e p em as ak a n m e n g g u n a k an aro n k u k u s. P a d a
p em a sak an m en g g u n ak an m eto d e
aron
ku kus
d id ap ati b eras
y an g tid a k len g k et
dan
d a p at m en jad i
b u tiran tu n g g al sa at d ik erin g k an .
4 .2
P e n e l i ti a n U t a m a
4 .2 .1
R a sio R e h id ra si
G am b ar rasio reh id ra si (G am b ar
9 ) m en u n ju k k an seb erap a b e sar d a y a serap sam p el terh ad ap
air. D ata terseb u t m en u n ju k k an tin g k at p e n y era p an air n asi u d u k in stan setela h d ik erin g k an . D ik e tah u i
b ah w a s am p el d en g an p erlak u an p en g erin g an A m em ilik i rasio reh id ra si y an g p alin g tin g g i, y aitu 5 ,8 .
S am p el in i m em ilik i rasio
pada
sam p el
in i.
reh id rasi p alin g tin g g i d iseb ab k an p en g erin g an b ertah ap y an g d ilak u k an
P en g erin g an
b ertah ap
y ang
d ilak u k an
m en guran gi
resik o
ca se
h a r d en in g .
C a se
h a rd en in g m eru p ak a n fen o m en a terjad in y a p en g eras an p ad a b a g ian k u lit ak ib at p em an a sa n b erleb ih an
y an g m en y eb ab k an k eru s ak a n p a d a sel s eh in g g a m en g k eru t d a n air d alam
b ah an p an g an tid a k d ap at
k elu ar s ec ara s em p u rn a. M eto d e p en g erin g a n b ertah ap , m em u n g k in k an air p a d a b ah an
teratu r
m en in g g alk an
sam p el.
P e n g erin g an
b ertah ap
in i
m en g h asilk a n
b eras
k elu ar se cara
in stan
y ang
leb ih
m en g em b an g d ari p en am p ak an lu ar, b ila d ib a n d in g k an d e n g a n s am p el lain n y a.
S am pel
d eng an
p erlak u an
p en g erin g a n
B
m em ilik i
rasio
reh id rasi
4.
D ata
terseb u t
m en u n ju k k a n b a h w a sam p el in i m asih m em ilik i k em am p u an reh id ra si, m es k ip u n n ilain y a tid ak se b aik
sam p el p ertam a. P en y eb a b
Suhu 60
o
p erb e d aa n ra sio reh id ra si in i a d alah
suhu
p e n g erin g an
yang
d ig u n ak a n .
C y a n g d ig u n ak a n , seb en arn y a m asih m as u k p ad a re n tan g su h u p en g erin g a n n asi u d u k in sta n ,
n am u n p e n g e rin g an sec ara lan g su n g ak a n m e n g a k ib atk a n air y a n g ad a p ad a b ah an p an g an tid a k d ap at
13
k elu ar s ec ara s em p u rn a. A ir y an g tertin g g al p ad a b a h an p a n g an ak a n m e n u ru n k an rasio re h id rasi b ah an
p an g an ters eb u t.
S am pel
k etig a, ad alah
sam p el d e n g an p erlak u a n p en g erin g an
C . S am p el terseb u t m em ilik i
rasio reh id rasi y an g p alin g ren d ah . N ilai terseb u t d iseb ab k an air y an g b erad a d alam
terseb u t tid a k k elu ar
sec ara
sem p u rn a
d ise b ab k an
o leh
c a s e h a rd en in g
p ada
n asi u d u k in stan
b aha n p an gan
tes eb u t
ak ib at c ara p e n g erin g an y an g tid ak te p at.
8
5. 8
6
4
4
3
2
0
A
B
C
G am b ar 9 . R asio reh id rasi b eras h a sil p erlak u a n
R o n g g a K o so n g ( V o id S p a ce)
4 .2 .2
N ilai vo id sp a c e y a n g d id a p at p a d a p en elitian in i m en g g am b ark an ro n g g a a n tar b eras d alam
w ad ah . M ak in b e sar n ilai ro n g g a an tar b eras , m en u n ju k k an u k u ran b era s y an g m ak in b e sar. S em ak in
b es ar b u tiran b eras m en u n ju k k an n ilai p o ro sitas b era s y an g s em ak in b e sar. S am p el d e n g a n p erlak u a n A
m em ilik i
n il a i
rongga
an tar
beras
d ala m
m e m i l i k i n il a i r o n g g a a n t a r b e r a s d a l a m
w ada h
p alin g
tin g g i
seb es ar
6 1 .8 % . S a m p e l
w a d a h s e b e s a r 4 9 .8 % . P e r l a k u a n C
p erlak u an
B
m em ilik i n ilai p erlak u an
an tar b era s p alin g ren d ah y aitu 4 3 .2 % .
M elalu i d ata terseb u t d ik eta h u i b ah w a b eras d e n g an p erlak u an A m em ilik i ro n g g a y an g p alin g
b es ar d ian tara d u a s am p el lain n y a . R o n g g a a n tar b era s y an g b esar, m en u n ju k k an u k u ra n b eras y a n g
b es ar. U k u ra n b eras y a n g b e sar, m en u n ju k k an p o ro sita s b eras y a n g b e sar . P erlak u a n C
rongga
an tar
b era s d alam
w ada h
y an g k ecil. N ilai terse b u t m e n u n ju k k a n
ukuran
m em ilik i n ilai
b eras
yang
k ecil.
S e m a k i n k e c i l u k u r a n b e r a s , m e n u n j u k k a n k o n d i s i p o r o s i t a s y a n g k e c i l p u l a ..
B esarn y a n ilai ro n g g a y an g d id ap at, b erh u b u n g a n d en g an rasio reh id rasi. R o n g g a b eras y a n g
b es ar, ak an m en g h asilk an n ilai rasio reh id rasi y an g tin g g i. N ilai rasio reh id rasi y an g tin g g i, d iseb ab k an
b eras m em ilik i ro n g g a y an g b esar. S a at d ilak u k an p ro ses reh id ra si, b eras d e n g a n u k u ran ro n g g a y a n g
leb ih b e sar ak an le b ih b a n y a k m e n y era p air. P ad a p e rlak u a n A , m em ilik i p o ro sita s y a n g p alin g tin g g i.
S aat
A n to n iu s K u rn ia an d B u d iatm an S atiaw ih ard ja
D ep artm en t o f F o o d S cien ce an d T ec h n o lo g y , F ac u lty o f A g ricu ltu ral T ech n o lo g y , B o g o r A g ricu ltu ral
U n iv ersity , IP B D arm ag a C am p u s, P O B O X 2 2 0 , B o g o r, W e st Ja v a, In d o n esia
P h o n e : + 6 2 8 1 3 1 6 3 3 2 5 2 7 , E - m a i l : a n t o n iu s k u r n ia @ y a h o o .c o m
A B STR A C T
R ice is th e sta p le fo o d fo r m o st o f In d o n esia n . T h e p r o d u ctio n o f rice in c rea se s e ve ry ye a r s. In 2 0 1 0 ,
t h e p r o d u c t i o n o f r i c e w a s a b o u t 6 5 ,9 8 b i l l i o n t o n ,w h i l e c o n s u m t i o n o f r i c e i s 1 3 9 ,5 k g / c a p i t a l / y e a r . B a s e d o n
th ese d a ta , th e d evelo p m e n t o f rice p r o d u ct is a p o ten tia l m a rket. N o w a d a y s m a n y p eo p le d o n o t h a v e m u ch tim e
to p r ep a re th eir fo o d . In sta n t fo o d is co m m o n ly ch o o se d b y th e m o d er n p eo p le . Q u ic k c o o kin g rice m eth o d s
h a ve b ee n co m m o n ly u se d sin c e 1 9 7 0 , b u t th eir p ro d u ct s a re n o t p o p u la r in In d o n e sia . T h e p u rp o s e o f th is
res ea rch is to p ro d u c e a q u ic k co o kin g ric e w ith sp ecia l ta ste n a tive to W e st S u m a te ra e, ca lled “ n a si u d u k ” .
T h e p re p a ra tio n in v o lve s s o a kin g , c o o kin g (g ela tin izin g ) a n d d ryin g u sin g flu id ize d b ed d ry er.T h is re se a rc h w a s
fo cu s ed o n to fin d o u t th e o p tim u m
d ryin g c o n d itio n s o r tr ea tm en t to p ro d u ce th e g o o d q u a lity o f q u ic k c o o kin g
r i c e . T h i s r e s e a r c h u s e d t h r e e d i f f e r e n t d r y i n g t r e a t m e n t s , n a m e l y A ,B , a n d C
co m b in a tio n
of
tim e
and
tem p e ra tu r e
h isto r y . It
w as
fo u n d
th a t
the
trea tm e n t w h ich w e re b a se d o n
o p tim u m
of
d ryin g
m eth o d
w as
th e
A
tra tm en t. In th e A tre a tm en t, th e ric e w a s fr ee zed fo r 2 4 h o u rs a t -2 0 ° C . A fter th a t, ric e w a s d ried fo r 3 0 m in u te s
a t ro o m tem p e ra tu r e a n d th en in cr ea sed th e tem p era tu re stra rt fro m
4 0°C , 60°C , and 80°C
fo r 1 0 m in u te s in
ea ch tem p e ra tu re. T h is m eth o d re su lted in a g o o d a c cep ta n ce f ro m p a n elists.
K eyw o rd s : q u ic k co o kin g ric e, d ryin g , flu id ized b ed d r ye r
ii
A N T O N IU S K U R N IA . F 2 4 0 7 0 0 9 5 .P en g a r u h P en g erin g a n T erh a d a p M u tu N a si U d u k In sta n . D i b aw ah
b im b in g an
D r .I r . B u d i a t m a n S a t i a w i h a r d j a , M .S c . 2 0 1 2 .
R IN G K A SA N
N asi ad ala h m ak an p o k o k b ag i se b ag ia n b e sar m as y arak at In d o n esi a. P ro d u k si b eras b erk em b an g teru s
setiap tah u n . P ad a 2 0 1 0 ,
tah u n .
B erd asarkan
bany ak
oran g
tid ak
d ata
p r o d u k s i b e r a s m e n c a p a i 6 5 , 9 8 j u t a t o n . K o n s u m s i b e r a s a d a l a h 1 3 9 ,5 k g / k a p i t a /
terseb u t,
m em ilik i
pen gem b ang an
w ak tu
cukup
bera s
u n tu k
da pat
m en y ia p k a n
m erupa ka n
pasar
m ak ana n
m ereka.
yan g
m e n j a n j i k a n .S a a t
Pro duk
in sta n
in i
um um ny a
sem a k in b an y ak d ig em ari u n tu k d ik o n s u m si. P ro s es p e n g o la h an n asi in stan m u lai d ik em b an g k an p ad a tah u n
1 9 7 0 , n am u n p ro d u k terseb u t tid ak d ip asark an d i In d o n esia.
T u ju an
d alam
p en elitian
k ali
in i
ad ala h
u n tu k
m e n g h asilk an
produ k
n asi
in sta n ,
d eng an
bum b u
trad isio n al y an g b eras al d ari S u m atra B arat, y an g d ise b u t n a si u d u k . P ersiap an p ro d u k n a si u d u k m elip u ti tah ap
p eren d am an , p em as ak a n , p em b e k u an , d an p en g erin g a n m e n g g u n a k an flu id ized b ed d r yer .
F o k u s p a d a p en elitian in i u n tu k m e n cari k o n d isi p en g erin g an y an g o p tim u m
yang
b aik . P en elitian k ali in i m en g g u n a k an
tig a p erlak u a n p en g erin g an
yang
u n tu k m e n g h asilk an p ro su k
b erb e d a, y aitu A , B , d an
m eru p ak an k o m b in a si d ari w ak tu d an su h u y a n g tep at. M e to d e p en g erin g an y an g o p tim u m
ad alah
m eto d e p en g erin g an A . K o n d isi p e n g erin g an A
m en it p ertam a m en g g u n ak an
p ad a su h u 4 0 ° C
60°C
ad ala h n asi d ik erin g k an
pada
d alam
C
i
p e n elitian in i
su h u ru an g s elam a
30
flu id ized b e d d ry er d en g an sp ee d b lo w er p ad a lev el 9 , selan ju tn y a d ik erin g k an
selam a 1 0 m en it d e n g a n s p ee d b lo w er d itu ru n k an p ad a lev el 7 , lalu s u h u d in aik k an m en jad i
s elam a 1 0 m en it m en g g u n ak a n b lo w er p ad a s p ee d 7 , d alam
1 0 m en it terak h ir su h u d in aik k a n m en jad i
8 0 ° C d en g an sp eed b lo w er lev el 7 . M eto d e p e n g erin g a n A m e n g h asilk an p en erim aan y an g p alin g b aik d ian tara
p erlak u a n lain n y a.
iii
I.
1 .1
PE N D A H U L U A N
L a ta r B e la k a n g
B eras ( O ry za sa tiva ) m eru p ak a n jen is serealia y an g d ijad ik a n m ak an a n p o k o k b a g i p en d u d u k
In d o n e sia.
B erd asark an
A n gka
R am alan
(A R A M )
III-2010
yan g
d ik elu ark an
o le h
B PS
d ik etah u i
b a h w a p r o d u k s i p a d i d i I n d o n e s i a s e b e s a r 6 5 ,9 8 j u t a t o n g a b a h k e r i n g g i l i n g ( G K G ) , n a i k 1 ,5 8 j u t a t o n
( 2 ,4 6 p e r s e n ) d i b a n d i n g p r o d u k s i t a h u n 2 0 0 9
s e b e s a r 6 4 ,4 0 j u t a t o n
y an g tin g g i d iim b an g i d en g a n tin g k at k o n su m si n a si d alam
G K G . K ap a sitas p ro d u k si b era s
n eg eri y an g tin g g i. T in g k at k o n s u m si n asi
d i I n d o n e s i a a d a l a h 1 3 9 ,5 k g / k a p i t a / t a h u n p a d a 2 0 0 9 . T i n g g i n y a k o n s u m s i n a s i d i I n d o n e s i a m e m b u a t
beras
m erupak an
k o m o d ita s
yang
san g at
b erp elu an g
u n tu k
d iek sp lo tiasi
leb ih
la n ju t
d alam
p en g elo laan n y a.
P en g o lah a n
bera s
sa at
in i
um um nya
d io la h
m en jad i
n asi
atau p u n
b eras.
P en g o lah an
bera s
trad isio n al u m u m n y a m em b u tu h k an w ak tu s ek itar 3 0 m e n it. W ak tu terseb u t m eru p a k an w ak tu u n tu k
m en an ak b era s h in g g a m atan g , jik a d itam b ah k an d en g an w ak tu p ersiap an n y a m ak a d ib u tu h k an w ak tu
sek itar
1
jam . T ah ap
p em a sak an
n asi
yan g
p a n jan g
m em b uat
p em a sak an n a si y a n g leb ih p rak tis d en g an m en g g u n a k an
m u d ah d an p ra k tis d alam
s eb a g ian
b esar
orang
rice co o k er. P e n g g u n a an
m em ilih
cara
rice c o o k er leb ih
p em as ak an n a si, m es k ip u n d em ik ian m a sih p erlu cara p em asa k an y an g leb ih
p rak tis d a n sia p d is an tap .
K ece nderun ga n
yang
b erkem b ang
d alam
m a sy a k arat
m od ern
sa at
in i
ad alah
m en g o n su m si
m ak an an in sta n y a n g d a p at d en g a n m u d a h d isiap k an d an d is an tap . T u n tu tan efesien si w ak tu , m em b u at
k o n s u m en u n tu k m em ilih m ak an a n in sta n s eb a g ai p o l a k o n su m si s eh ari -h ari.
P ro d u k m a k an an in stan y an g saat in i b ered ar d i p as aran san g at jaran g y an g m en g g u n ak an b era s
seb ag ai
bahan
dasarnya .
M aka nan
in stan
yang
s elam a
in i
d iju al
m em ilik i
k esan
m en g e n y a n g k an k o n su m en , ta n p a m em b erik an k ep u as an b ag i k o n su m e n . Istilah “ b elu m
b elu m
han ya
u n tu k
m a k an , k alau
m ak an n asi” m em b u at m ak an an in sta n terseb u t h an y a m en ah an lap ar k o n s u m en , d a n k o n su m en
tetap m eras a “ b elu m m a k an ”.
P en g em b a n g a n tek n o lo g i n a si siap s aji su d ah lam a d ik em b a n g k an , n am u n u n tu k p ela k sa n a an n y a
d alam
p as ar In d o n e sia m asih su lit u n tu k m ereb u t h ati k o n su m en . P ro d u k n a si in stan y an g p ern ah a d a
um um ny a
karena
d isajik an
k arak teristik
d alam
n asi
b e n tu k
goreng
n a si
in sta n
g o ren g . N asi
tid ak
sam a
goren g
s ep erti
in stan
n asi
terse b u t
goreng
y ang
su lit
m enem bu s
um um ny a
p a sar,
d ik o n s u m si
m asy arak at.
H asil
o lah an
lain
dari
beras
ad ala h
n asi
u d u k , selam a
in i
n asi
uduk
telah
d ik en al
lu as
o leh
m asy arak at k h u su sn y a d i p u lau Jaw a. M en g k o n su m si n asi u d u k b u k a n lah h al y a n g asin g b ag i se b a g ian
m asy arak at. N a si u d u k in sta n m u n g k in d ap at d iterim a o leh k o n s u m en , seh in g g a d ap at d ik em b a n g k an
leb ih lan ju t d alam
1 .2
sk ala y an g le b ih b esar.
T u ju a n P e n e litia n
P en elitian in i m em p u n y ai tu ju a n u n tu k m en g etah u i p en g aru h p en g erin g a n p ro d u k n a si u d u k
in stan sia p s aji d en g an m en g g u n ak an p en g erin g flu id ized b e d d rye r.
1
II.
2 .1
T IN J A U A N P U S T A K A
S e k ila s T e n ta n g N a s i I n sta n
N asi in stan
ad ala h
d en g an c ara p ersiap an y an g
n asi ce p at m a sak
y an g d a p at d isia p k a n d alam
sed erh an a. N a si in stan m em ilik i
w ak tu 3
sam p ai 5 m e n it
c i ri k h a s d e n g a n b u t i r b e r a sn y a y a n g
d ib u at p o ro u s. S tru k tu r y an g leb ih p o ro u s a k an m em p erc ep at air p an as y an g m asu k k e d al am n y a s aat
d ireh id rasi. S etelah d im a sa k , p ro d u k h aru s se su ai d en g an n asi b ias a d alam
h al rasa, aro m a, d a n tek stu r
(R ew th o n g ,et al, 2 0 1 0 ) . J en is b eras y an g d ig u n ak a n u m u m n y a a d alah b eras d en g an b u lir p an jan g , atau
beras
lo n g
g ra in .
B era s
den gan
b u lir
p an jan g
um um ny a
m em ilik i
b en tu k
d ik erin g k a n k em b ali, k are n a d ap at m en y eru p ai b en tu k b u tir b eras s eb elu m
y ang
leb ih
b aik
saat
d ik erin g k an
T ab el 1 . N ilai N u trisi B eras
Z at G izi
K adar
K arb o h id rat
79%
L em ak
0 .6 6 %
P ro tein
7 .1 3 %
A ir
12%
S u m b er : N u trisi D ata U S D A ,2 0 1 2
N asi in stan d ib u at d e n g a n cara p erlak u an p em as ak a n aw al d an g elatin isasi d en g an m e n g g u n a k an air,
uap
ata u
ga bun gan
k ed uan ya.
G elatin is asi
p ati
d ise b ab k an
o le h
pem ben gka ka n
g ran u la
ak ib at
p em an as an y an g m en y eb a b k a n terjad in y a p en ek a n an g ran u la satu d an la in n y a. P em b en g k ak an g ra n u la
b ersifat reve rsib le, n am u n k etik a m elew ati su h u 6 8 -7 8 ⁰ C
p em b en g k ak an g ran u la b ersifat irre ver sib le
y a n g d i s e b u t g e l a t i n s a s i . S u h u t e r s e b u t d i s e b u t s u h u g e l a t i n i s a s i ( F e n n e m a ,1 9 8 5 ) .
K isaran su h u y an g m e n y eb a b k a n 9 0 % b u tir p ati d alam
air p an a s m em b e n g k ak d an tid ak d a p at
k em b ali p a d a b en tu k as aln y a d ise b u t B irefrin g en t E n d P o in t T em p era tu re atau d is eb u t B E P T . K is aran
beras y ang
ad a d ip a saran m em p u n y ai B E P T
ren d ah (5 5 -6 9 ⁰ C ), m ed iu m
(7 0 -7 4 ⁰ C ), d an tin g g i (7 5 -
7 7 ⁰ C ) ( J u l i a n o ,1 9 7 2 ) . G e l a t i n s a s i p a t i a k a n m e n y e b a b k a n p e r m u k a a n b u t i r b e r a s m e n j a d i r e t a k . B i l a
d im asa k ,
p eng em ba ga nny a
tid ak
se b e sar
p eng em ba gan
p ati
asal.
T ertah a n n y a
p en gem b ang an
in i
d iseb ab k an p em b atas o leh k o m p o n en n o n p ati. G el atin sasi g ran u la p ati m eru p ak an sala h s atu la n g k ah
k u n ci d alam
p em b u ata n n asi cep at s aji. G elatin sa si p ati b ersifat irr eve rsib el, d an m eru p a k an h al y a n g
p en tin g d alam
p ro ses reh id ra si b eras in sta n k erin g y an g terg elatin isasi sem p u rn a u n tu k d isiap k an d an
d ik o n s u m si (W irak artak u s u m ah y a n g d ia cu o leh F ird h au s 2 0 0 3 ) .
N asi in stan d ap at d ib e d ak an m e n jad i b eb erap a tip e b erd a sark a n tin g k at k ad ar air, su h u , w ak tu
p e m a s a k a n a w a l , d a n k o n d i s i p e n g e r i n g a n ( L u h , e t a l ,1 9 8 0 ) . B e r d a s a r k a n p e r l a k u a n i n i d a p a t d i h a s i l k a n
b eb era p a je n is n asi in sta n , y aitu :
1.
U n d e r co o k ed rice y an g m em b u tu h k an w ak tu 1 0 -1 5 m e n it w ak tu p en y ajian
2.
T a ke rice m em b u tu h k an w ak tu 5 m en it u n tu k p ersia p a n
3.
M in u te rice m em b u tu h k a n 1 -2 m en it u n tu k p ersia p an
4.
R ea d y to e a t b r ea kfa st ce re a l d ap at lan g su n g d is a n tap
S elam a
d ip aten k an (L u h
em p at
p u lu h
tah u n
terak h ir
bany ak
m eto d e
p em b u atan
b eras
in sta n
e t a l ,1 9 8 0 ) . M e t o d e y a n g b e r k e m b a n g d a p a t d i k e l o m p o k k a n d a l a m
yan g
telah
1 0 je n is m eto d e
p em b u atan . M eto d e t erseb u t terb ag i d alam :
1.
B eras m u la-m u la d iren d am
d alam
air sam p ai k ad ar air m en jad i 3 0 % . K em u d ian d im as ak
deng an
kadar
air
air
pan as
sam p ai
50 -60
%
den ga n
atau
tan p a
m en ggu nak an
u ap.
K em u d ian p ere b u san atau p e n g u k u san d iteru sk an sam p ai k ad ar airn y a m e n jad i 6 0 -7 0 %
d an k em u d ian d ik erin g k a n d e n g a n h ati-h ati sam p ai k a d ar air 8 -1 4 %
stru k tu rn y a
b erp o ri.
M o d ifik asi
yan g
d ilak u k a n
terh a d ap
c ara
in i
d en g a n m en jag a ag ar
an tara
lain
d eng an
2
p e r l a k u a n p a n a s k e r i n g p e n d a h u l u a n u n t u k m e m b u a t b e r p o r i - p o r i b u t i r - b u ti r b e r a s s e b e l u m
d im asa k d a n d ik erin g k an .
2.
B eras
d iren d am ,
d ireb u s,
d ik u k u s
deng an
tek a n a n
u n tu k
m em bu at
b u tir -b u tir
beras
terg elatin isasi, d k erin g k a n d en g an su h u y a n g re n d a h u n tu k m en g h asilk an b u tir -b u tir b eras
y an g a g ak b erat d an m en g k ilat, k em u d ian d ib eri p erlak u a n d e n g a n p en g em b an g an p a d a
tek an a n d an su h u tin g g i u n tu k m em p ero leh stru k tu r b erp o ri -p o ri y an g d iin g in k an .
3.
B eras d ip re g elatisa si, d ig ilin g atau d itek a n u n tu k m em p ero leh b u tiran y an g ag ak g ep en g
dan
k em u d ian d ik erin g k a n u n tu k m em p ero leh
b u tiran b eras
den gan
k a d ar air 1 2 %
d an
m en g k ilat.
B e r a s d i b e r i p e r l a k u a n d e n g a n u d a r a p a n a s y a n g m e n g a l i r c e p a t p a d a s u h u 6 5 ,6 – 3 1 5 ,6 ˚ C
4.
u n tu k
m em bu at
proses
d ek strin asi
p ati
d alam
b eras,
m em bu at
berp ori -pori
atau
m en g em b an g k a n b u tiran b eras .
5.
B eras d iaro n , k em u d ia n d ib ek u k an , d ith a w in g d an d ik erin g k an .
6.
M eto d e G u n P u ffin g
y ang m erupa kan
k o m b in asi d ari p erlak u a n -p erlak u an p en d ah u lu an
terh ad ap b eras d en g a n p en g g u n aa n s u h u d an te k a n an tin g g i, d iik u ti d en g an p e n g elu aran
sec ara c ep at k e d alam ru an g a n y a n g te k an an n y a le b ih ren d ah .
7.
N asi m a sak d en g a n p e n g erin g an b ek u .
8.
P erlak u a n ata u p em b erian b ah an k im ia.
9.
K o m b in asi 2 ata u leb ih d ari m eto d e d iatas
1 0 .M e t o d e l a i n .
M en u ru t H u b eis (1 9 8 4 ), b eras in stan y a n g d in ilai p alin g b aik m elalu i ta h ap an se b ag ai b erik u t :
perend am an
b eras
dengan
laru tan
N a2H P O
0 ,2
4
%
selam a
18-19
jam
(pH
5 ,2 ) ;
p en etralan
deng an
N a O H 1 N ( p H 7 ,0 - 7 ,3 ) ; p e m a s a k a n s e l a m a 7 m e n i t ; p e n g u k u s a n 1 0 m e n i t ; p e n c u c i a n d a n p e n g e r i n g a n .
B eras
in stan
yang
d ih a silk an
m elalu i
p ro ses
terse b u t
d ap at
d iu b ah
m en ja d i
n a si
m elalu i
p ro se s
r e h i d r a s i . K a d a r a i r b e r a s i n s t a n s e b a g a i p r o d u k a k h i r d a p a t b e r k i s a r 9 - 1 2 ,5 % y a i t u s u a t u k e a d a a n a m a n
sim p an d im a n a n ilai k ad ar air terseb u t d alam
k ead aa n setim b a n g d e n g an k o n d isi lin g k u n g a n n o rm al.
P ati y an g telah m en g alam i g elatin isasi d ap at d ik erin g k an , tetap i m o le k u l-m o lek u l ters eb u t tid ak d ap at
k em b ali lag i k e sifat-sifat asaln y a se b elu m
m en y era p air d alam
air
k em b ali
g elatin isa si. B a h an y an g telah k erin g terseb u t m a sih m am p u
ju m lah y an g b esar. S ifat in ilah y an g d ig u n a k an ag ar b era s in sta n d ap at m en y erap
den gan
m u da h,
y aitu
d eng an
m e ngg una kan
p ati
yan g
telah
m e n g alam i
g elatin isasi
(W in arn o , 1 9 8 4 ).
2 .2 .
T a h a p P em b u a ta n N a si In sta n
T aha p
p em b u atan
p eren d am an d alam
d alam
air
d in g in
n asi
p eren d am an d alam
4
0 .2 %
dap at
d ilak u k an
dengan
be berap a
cara,
d ia n taran y a
ad alah
laru tan k im ia, p em b ek u an , d an p e n g erin g a n . P ad a d a sarn y a p ati y a n g d im as u k k an
aka n
m en yerap
d iserap terb atas d an h a n y a 2 6 %
N a2 H P O
in sta n
air
dan
aka n
terjad i
peng em ba ng an
p ati. T eta p i
ju m lah
air
yang
d ari b erat aw al. U n tu k m en in g k atk an d a y a s erap air p erlu d ilak u k an
laru tan k im ia. M en u ru t H u b eis (1 9 8 4 ), p ere n d am an d ap at d ilak u k an d alam
selam a 1 8 jam . G aram
n atriu m
laru tan
fo sfat ak an m en g a k ib atk a n stru k tu r fisik b eras p as ca
tan ak le b ih p o ro u s, h al in i m en y eb a b k a n p en y erap an
air ak an
leb ih
cep at pa da
w a k tu
peren dam an
m au p u n reh id rasi. P en am b ah an fo sfat s eb a g ai se n y a w a y an g m e n g io n p ad a p ro d u k y a n g b erasal d ari
p ati ak an m en y eb ab k an g ran u l a p ati tah an terh ad a p retro g rad asi selam a p en d in g in an d an p e n in g k atan
su h u s etelah p en d in g in an .
T ah a p p em b u at an b erik u tn y a ad ala h p em b e k u a n . P ro ses p em b ek u an d a n p e n y im p a n an b e k u
ak an m e n in g k atk an p en g em b a n g a n m o le k u l p ati. P em b e k u a n a k a n m ele p a sk a n air y an g terd a p at d alam
sistem
g el.
P ro se s
in i
d ilak u k a n
u n tu k
m en g h a silk an
sifat
p o ro sitas
y ang
tin g g i
s eh in g g a
w ak tu
reh id rasi m en jad i sem ak in sin g k at.
N asi in stan d a p at m en y erap air p an as d en g an ce p at se h in g a d ap at d ik o n s u m si d alam
b ebera pa
m en it. N asi in stan d ap at terb en tu k b ila p o ri -p o ri b eras terb u k a leb ar s eh in g g a m em u d a h k a n reh id rasi
dan
d ip ero le h
lam b at s eb elu m
w ak tu
reh id rasi
y an g
sin g k at, cara
n asi d ik erin g k a n . P em b ek u an
yang
dap at
d ilak u k a n
ad alah
den ga n
pem b eku an
lam b at y a n g m en g h a silk an k ristal es y an g b esar ak an
3
m em b u at ro n g g a p o ri y an g b e sar u n tu k d ih id rasi d en g an c ep at, seh in g g a u k u ra n b era s m e n jad i leb ih
besar.
P em be kua n p ada
su h u
0
-20
C
selam a
20
jam
m en g h a silk an
stru k tu r
k ristal es y an g
b e sar,
p ro se s in i m em e cah k an stru k tu r k o lo id p ati d a n m e n g h asilk a n stru k tu r k ern el y a n g p o ro u s (R ew th o n g
et al, 2 0 1 0 ) . P ro d u k y an g d ih a silk an d ap at d e n g a n c ep at m e n y era p a ir p a d a p em a sa k an k em b ali.
T aha pan
s elan ju tn y a
dari
p em b u ata n
n asi
in stan
ad alah
p e n g erin g an .
P e n g erin g an
ad alah
m eto d e u n tu k m en g aw etk an b a h an p an g an . T u ju an p en g erin g an a d alah m e n g u ra n g i k ad ar air b ah an
sam p ai
m endap at
b io lo g is
dan
kadar
k im ia
air
terten tu
se b elu m
b aha n
yang
dap at
d io lah
m engh am bat
ata u
laju
d im an fa atk an .
k eru sa k an
b aha n
P en guran gan
ak ib at
kad ar
air,
ak tiv itas
m em buat
k o m p o n en zat g izi p ad a k o n s en trasi y an g le b ih tin g g i.
P en g erin g an
adalah
su atu
p eristiw a
p erp in d ah an
m as sa
dan
energi
yan g
terjad i
d alam
p em isa h an air ata u k elem b a b an d ari su atu b ah a n sam p ai b atas k a n d u n g a n air y an g d iten tu k an d en g an
m engg una kan
udara
seb ag ai
flu id a
su m b er
pa nas
dan
p en erim a
uap
c airan
(T rey b al,
1 981).
P en g erin g an m a k an an m em ilik i d u a tu ju an u tam a. T u ju a n p e rtam a ad alah s eb a g ai saran a p en g aw etan
m akan an.
b ertah an
M ik ro o rg a n ism e
h id u p
p ada
y ang
m e n g a k ib atk a n
lin g k u n g a n
d eng an
k eru sak an
kad ar
air
yang
m a kan an
re nda h.
tid ak
S elain
d apat
itu ,
berk em ba ng
b any ak
en zim
d an
yang
m en g a k ib atk a n p eru b ah an k im ia p ad a m ak a n an tid a k d ap at b erfu n g si tan p a k eh ad iran air (G ean k o p lis,
1 9 9 5 ). T u ju an
yang
telah
ked ua
ad ala h u n tu k m em in im alk a n b ia y a d i strib u si b ah an m a k an an
d ik erin g k a n
ak an
m em ilik i
berat
yang
leb ih
rend ah
dan
ukura n
karen a m ak an an
yan g
leb ih
k ecil .
P en g erin g an m e ru p a k a n o p erasi y an g ru m it y an g m elip u ti p erp in d ah a n p an a s d an m as sa se cara tran sien
serta b eb era p a laju p ro se s, sep erti tran sfo rm asi fisik ata u
k im ia, y an g d ap at m en y eb ab k an p eru b ah an
m u tu h a sil m au p u n m ek an ism e p erp in d ah an p an as d an m as sa. P eru b ah a n fis ik y a n g m u n g k in terjad i
m elip u ti : p en g k eru tan , p en g g u m p u lan , k ristalisasi, tran sisi g elas. p a d a b eb erap a k a su s, d ap at terjad i
reak si
k im ia
atau
b io k im ia
yan g
d iin g in k a n
ata u
tid ak
d iin g in k an ,
yang
m en yeb abk an
perub ah an
w arn a, tek stu r, aro m a atau sifat lai n p ad atan y an g d ih asilk a n . P e n g erin g a n terjad i m elalu i p en g u ap an
cairan d en g an p em b erian p a n a s k e b a h an u m p an b as ah
P ad a u m u m n y a zat p ad at selalu m en g an d u n g se d ik it frak si air seb a g ai air terik at. Z at p ad at
y an g ak a n d ik erin g k an b ias an y a terd ap at d alam
b en tu k serp ih (flak e), b ijian (g ran u le), k ristal (cry stal),
serb u k (p o w d er), lem p e n g (sla b ), atau lem b aran
berbed a
satu
sam a lain . Z at c air y an g
a kan
sin am b u n g (co n tin o u s sh eet) d en g a n sifat -sifat y an g
d iu ap k an m u n g k in terd ap at p ad a
sep erti p ad a k ristal; d ap at p u la s elu ru h zat c air terd ap at d i d alam
perm u kaa n z at p adat
zat p ad at sep erti p ad a p em is ah an
p elaru t d ari lem b ara n p o lim er; atau d ap at p u la seb ag ian z at cair s eb a g ian d i lu ar d an seb ag ian d i d alam .
U m p an p en g erin g m u n g k in b eru p a zat cair d i m an a zat p ad at m ela y an g s eb ag ai p artik el, atau d ap at
p u la b erb en tu k laru tan . H a sil p en g erin g an a d a y an g tah a n terh ad ap
b erad a d alam
su h u
ren dah
lin g k u n g a n y an g sa n g at p a n a s, ad a p u la
ata u
p ad at d i d alam
sed an g . P erb ed aan
p en g erin g
p en a n g a n an m ek a n ik k a sar d an
y an g m em erlu k an p en a n g a n an
teru tam a
terletak
d alam
hal
cara
h ati-h ati p ad a
m em in d ah k an
zat
zo n a p en g erin g d a n d alam p ro s es p erp in d ah a n k alo rn y a.
P ro se s p e n g erin g an m e n g h asilk a n stru k tu r p o ro u s y an g ak an m em u d ah k an air u n tu k d ap at
m eresa p k e
d alam
b eras
sa at reh i d rasi. S u h u
o p tim u m
p e n g erin g a n n asi in sta n
m en u ru t R ew th o n g ,
2 0 1 0 a d alah 8 0 ° C . S em e n tara m en u ru t Ja d in g et al, 2 0 1 1 , su h u u n tu k m en g erin g k an g ran u la b erk isar
an tara 6 0 – 7 0 ° C .
2 .3 .
F lu id iz e d B e d D r y e r
T ek n o lo g i F lu id ized b ed d r yer m eru p a k an sala h satu altern atif p ilih an tek n o lo g i p en g erin g a n ,
karena
te k n o lo g i
k o n v en sio n al
produk
de ng an
kom pak,
in i
lain n y a,
m em ilik i
p erp in d ah an
se h in g g a
k ap a sitas
kan dun gan
dengan
in v e stasi
air
yan g
aw al
serag am
relatif
pan as
dan
p en g erin g an
m as sa
da pat
le b ih
leb ih
b aik
b e sar
(S ireg ar, 2 0 0 6 ). T ek n o lo g i
rendah
dan
um um n ya
tek n o lo g i
dari
d an
flu id ized
in i
jen is
d ap at
bed
d ip ak ai
p e n g erin g an
m en g h a silk an
drye r
u n tu k
cuk up
prod uk
b erb en tu k g ra n u lar (M u ju m d ar A S d a n D ev a h a stin S , 2 0 0 3 ). P e n g erin g an m en g g u n ak a n flu id ized b ed
d ry er m em ilik i b eb erap a k eu n tu n g a n , d ia n taran y a :
a.
L aju p en g erin g an tin g g i, k aren a p er s en tu h an an tara p artik el d an u d ara y a n g terjad i sa n g at b aik
b.
L u as p erm u k aa n b a h a n y a n g b erse n tu h a n d en g an aliran u d ara le b ih b esar
c.
E fisien si p a n as tin g g i k are n a k o efisien laju p in d ah p an as d an p in d a h m a ss a m em b es ar
d an m en y eb a b k a n tin g g in y a laju p in d ah p a n a s d a n m a ss a.
4
d.
B iay a in v esta si d a n p em elih araan relatif leb ih ren d ah
P rin sip k erja p ad a alat flu id ized b ed d r ye r d en g an m en iu p k an u d ara p a n a s d ari b ag ian b aw ah
bed.
U dara
pa nas
terse b u t
a kan
m en arik
air
yan g
ada
pada
bah an
u n tu k
k elu ar, s eh in g g a
terjad i
b u b b lin g d a n m e n g a n g k at p ro d u k y an g ad a d iat as b ed . T in g k at b u b b lin g y an g terjad i terg a n tu n g p a d a
besaran
ud ara
yan g
d itu p k a n
( S i r e g a r ,2 0 0 6 ) .
P rin sip
flu id ized
k erja
bed
drye r
dap at
d ilih at
pada
G am bar 1
P lat p erfo rasi
U dara
U dara
U dara
U dara
U dara
U dara
1
2
3
4
5
6
P artik el d alam
p artik el m u lai
P artik el
flu id isasi
flu id isasi
tran sp o rt
k ead aa n d iam
terflu id isasi
terflu id isasi
terb aik
d alam
p n eu m atik
k o n d isi
pada ba han
b erleb ih an
k erin g
G am b ar 1 . P rin sip k erja flu id ized b ed d ry er
F lu id ized b ed d r yer terb ag i ata s b eb erap a b ag ia n , y aitu :
a. B lo w er
B lo w er b erfu n g si u n tu k m e n g h asilk a n aliran u d ata y a n g ak an d ig u n ak a n p ad a p ro s es flu id isasi.
K ip as ju g a b erfu n g si se b ag ai p e n g h em b u s u d ara p an a s k e d alam
ru ang
p en g erin g d an u n tu k
m en g a n g k at b a h an ag ar p ro se s flu id isa si terjad i.
b . E lem en P em an as
E lem en p em a n a s b erfu n g si u n tu k m em a n as k an u d ara h in g g a k elem b a b an relatif u d ara p en g erin g
tu ru n , d an
k alo r
y ang
d ih asilk a n
d ib aw a
o le h
aliran
ud ara
y ang
m elew ati
elem e n
pem ana s
seh in g g a p ro se s p en g u a p an air d ari d alam b ah an d ap at b erlan g su n g .
c. H oppe r
H opper
b erfu n g si se b ag ai tem p at m em asu k k an b ah a n y an g ak an d ik erin g k a n k eru an g p e n g erin g
d . T h er m o c o u p le
T h er m o c o p u le b erfu n g si se b ag ai p e n g u k u r tem p eratu r u d ara m asu k d an u d ara k elu ar.
P en g erin g an m en g g u n ak an F lu id ized b e d d ry er d a p at d ig u n a k an u n tu k m e n g erin g k an g ran u la.
P en g erin g an
m e ngg una kan
F lu id iz ed
b ed
d rye r
m am p u
m em p ertah an k an
k o m p o sisi
k im ia
dan
m e m p e r b a i k i s i f a t f i s i k o k i m i a p a t i s a g u k e r i n g ( J a d i n g e t a l ,2 0 1 1 ) . K e m a m p u a n u n t u k m e n g e r i n g k a n
g ran u la
in i
d iseb ab k an
kem am pu an
alat
u n tu k
m enc apai
p ro ses
flu id isa si
yang
o p tim al
seh in g g a
m am p u m e n c ap ai w ak tu p en g erin g an y a n g sin g k at.
5
a. G ran u la p ati b as ah
b . G ran u la p ati h asil
c. G ran u la
p ati
p en g erin g an
p en g erin g an
m en g g u n a k an F lu id ize d
k o n v en sio n al
h a sil
b ed d ry er
S u m b e r : J a d i n g e t a l ,2 0 1 1
G am b ar 2 . B en tu k g ran u la p ati
6
III.
3 .1
B A H A N D A N M E T O D E
B a h a n d a n A la t
B ah a n u tam a y an g d ig u n a k an d i d alam
p en elitian in i ad alah b eras s erta b u m b u n a si u d u k y a n g
m elip u ti sereh , d a u n jeru k , s an tan , d an g aram . B era s y a n g d ig u n a k an d alam
p era v arietas IR
ad alah
4 2 d an b eras p u l en v arietas IR
64
p e n elitian in i ad alah b era s
d en g an p erb an d in g a n 2 :1 . A lat y an g d ig u n ak an
f l u i d i z e d b e d d r y e r ,p a n c i , d a n d a n g , k o m p o r , t i m b a n g a n a n a l i t i k , g e l a s p e n g a d u k , t e r m o m e t e r ,
w a terb a th , g elas u k u r, c aw an
alu m u n iu m , g ela s p iala, d a n alat g ela s lain u n tu k
a n alisis p ro k sim at.
K o m p o si si b ah an m em b u at n a si u d u k d ap at d ilih at p ad a T ab el 2 .
T ab el 2 . K o m p o sisi b ah an n asi u d u k
B aha n
K o m p o s is i
B eras
500 g
A ir
600 m l
S an tan
20 m l
P en y ed a p (ro y co sa p i)
2 g
G aram
8 g
S ereh
10 g
D au n S alam
5 g
G a m b a r 3 .B a h a n m e m b u a t n a s i u d u k
S p esifik asi :
M odel N o. A P S . 6
S e r i a l N o .: A P S - B 1 4 2 6
E C t y p e - a p p r o v a l N o .: T 6 1 2 6
T e s t C e r t i f i c a t e N p .: T C 6 1 0 1
M F D B y : U W E C o ., L td .
G am b ar 4 . T im b an g an
S p esifik asi :
T y p e : F lu id B ed D ry er
M odel N o. M K II
S e r i a l N o .: F N D / 2 4 0 / 9 1 / 5 7 4 2
M ad e b y : A rm field
G am b ar 5 . F lu d ize d B ed D rye r
7
3 .2
M e t o d e P e n e l it i a n
M eto d e p en elitian y an g d ig u n a k an d alam p en elitian in i terd iri d ari p en elitian p en d ah u lu an d an
p en elitian u tam a . B erd a sark a n p en elitan terd ah u lu o l eh F ird h a u s ( 2 0 0 3 ), telah d iteliti ten tan g m eto d e
p en g erin g an n asi in stan b eru p a p en g aru h p ere n d am an d alam
perend am an
d alam
laru tan
k im ia,
m en g h asilk a n n asi in sta n y an g
N a2H P O
4
b aik .
m eto d e
pem asaka n
P a d a ta h ap
laru tan N atriu m
ju g a
p erlu
F o sfat. S elain p en g aru h
d ip erb aik i
d alam
p e n d a h u lu a n d ilak u k a n p eren d am an
k aitan n y a
d alam
laru tan
seb e sar 0 ,2 % s elam a 1 2 0 m en it. P a d a p em a sa k an d ig u n ak an reto rt u n tu k m em a sak n a si u d u k
(G am b ar 6 ). P ad a tah a p p e n d a h u lu a n ju g a
d ilak u k an p em a sak an m e n g g u n a k an m eto d e
aron k uku s .
P em as ak an n asi u d u k m en g g u n ak an reto rt d en g an m en g g u n ak an s u h u 1 2 1 ˚C , d e n g a n 3 ren ta n g w ak tu
yang
b erb e d a y aitu 5 , 1 0 , d an 1 5 m en it. S etelah b eras m ata n g k em u d ia n d ico b a u n tu k d i b ek u k a n .
P em b e k u a n b eras d ila k u k an s elam a
d ib u at p a d a tah ap
p en d ah u lu an
2 4 jam
pad a suhu
ad ala h 6 0 ° C
dan
-20˚C
p a d a freez er. S u h u p en g erin g an
8 0 ° C . P en g am atan
yang
y an g d ilak u k an terh ad a p tah ap
p en d ah u lu an ad ala h p en g am atan se cara v isu al h a sil p en g erin g an .
B eras
P en c u cian
P eren d am an selam a 1 2 0 m e n it + N a 2H P O
4
0 ,2 %
P em as ak an d alam
P em as ak an d alam
P em as ak an d alam
reto rt selam a 5 m en it +
reto rt selam a 1 0 m en it
reto rt selam a 1 5 m en it
penam bah an bum b u
+ pe nam b aha n b um bu
+ pe nam b aha n b um bu
P en g aro n a n s elam a 1 0
m en it + b u m b u
P en g u k u sa n s elam a
3 0 m e n it
P em b e k u a n s elam a 2 4 jam
P en g erin g an
P en g erin g an
su h u 6 0 ° C
su h u 8 0 ° C
N asi U d u k
In sta n
G am b ar 6 . S k em a P em b u atan N asi U d u k In sta n tah ap p en elitian p en d ah u lu an
S etelah m em p ero leh d ata p en g am atan h asil p e n elitian p e n d a h u lu a n (lih at p ad a B ab H asil d an
P em b a h a san ), d ilak u k a n p e n elitian u tam a s ep erti terlih at p ad a G am b ar 7 . P ro s ed u r in i b erfo k u s p a d a
p erlak u a n p en g erin g an y an g d id u g a ak an p alin g b erp en g aru h terh ad a p p ro d u k
8
B eras
P en c u cian
P eren d am an selam a 1 2 0 m e n it + N a 2H P O
4
0 ,2 %
P en g aro n a n s elam a 1 0 m e n it + p e n am b ah an b u m b u
P en g u k u sa n s elam a 3 0 m e n it
P em b e k u a n ( free zin g ) s elam a 2 4 jam
P erlak u a n p en g erin g an A
P erlak u a n p en g erin g an
N asi U d u k
G am bar
A
yang
P erlak u a n p en g erin g an C
In sta n
7 . S k em a P em b u atan N asi U d u k In stan tah ap p en elitian u tam a
P erlak u a n p en g erin g an
p en g erin g an
B
d im ak su d
y a n g d ig u n ak an p ad a p en elitian u tam a
ad ala h
n a si
yang
tela h
y aitu A , B
d ib ek u k an , d ik erin g k a n
d an C . P erlak u an
pad a
F lu id ized
B ed
D rye r p ad a su h u k am ar d an k e cep atan b lo w er d is et p ad a lev el 9 selam a 3 0 m en it p ertam a. S elan ju tn y a
su h u d in aik k an m en ja d i 4 0 ˚C
selam a
1 0 m en it d a n k ece p atan
b lo w er d itu ru n k an
p a d a le v el 7 . S u h u
b lo w er selan ju tn y a d in aik k an m e n jad i 6 0 ˚C selam a 1 0 m en it d an k ec ep ata n b lo w e r tetap
P ad a 1 0 m en it terk ah ir su h u d in aik k a n m e n jad i 8 0 ˚C d en g an k e cep atan b lo w e r
P erlak u a n p e n g erin g a n B
p ad a lev el 7 .
tetap p a d a lev el 7 .
p a d a p en elitian in i d ilak u k a n d en g a n p erlak u an
p en g erin g an
n asi
y an g telah d ib e k u k an p ad a F lu id iz ed B ed D r ye r d en g an su h u k am ar d a n lev el k e ce p atan b lo w er p a d a
lev el 9 selam a 3 0 m e n it. S etela h itu F lu id iz ed B ed D ry er d in aik k an m en ja d i 6 0 ˚C
d itu ru n k an m en jad i lev el 7
p en g erin g an
k ec ep ata n
n asi
b lo w er
selam a
3 0 m en it. P erlak u an
yan g
telah
d ib ek u k an
pad a
lev el
9
selam a
p ada
30
F lu id iz ed
p en g erin g a n C
B ed
m en it. K em u d ian
d alam
D rye r
den gan
su h u
F lu id iz ed
d a n lev el b lo w e r
p en elitian in i ad alah
suhu
k am ar
dan
B ed
D ry er
d in aik k an
lev el
m en jad i 8 0 ˚C serta k ece p ata n b lo w e r d itu ru n k an p a d a lev el 7 selam a 3 0 m en it.
P ro se s reh id rasi n a si u d u k in stan d ilak u k an d en g an m e n aru h b eras d alam
gram
d a n air d en g an su h u 9 0 ° C
g ela s se b an y ak 2 0
se b a n y a k 1 5 0 m l d an d iam k an selam a 5 m e n it (G am b ar 9 ). A n alisis
y an g d ilak u k a n ad al ah rasio reh id rasi, p o ro sitas, o rg a n o lep tik serta p ro k sim at u n tu k h a sil terb aik . U ji
o rg an o le p tik terh ad ap n asi in sta n k erin g y an g tela h d ireh id rasi d e n g a n m en g g u n ak an u ji h ed o n ik sk ala
9
tu ju h . A n alisis o rg a n o lep tik in i m en g g u n ak a n u ji ratin g h ed o n ik m en g g u n ak an 3 0 p an elis y an g tid ak
terlatih . T ah ap p ertam a an alisis m en g g u n ak a n A N O V A u n tu k m en g eta h u i p en g aru h tah ap a n p erlak u an
p en g erin g an
pada
taraf
sig n ifik an si
5
% .
S etela h
d ik eta h u i
terd a p at
p erbed aan
sig n ifik an
d ian tara
k etig a p erlak u an , k em u d ian d ilak u k an u ji lan ju t y an g b eru p a u ji D u n can u n tu k m en g et ah u i sam p el d ari
p erlak u a n m a n a y a n g b erb e d a d ari tiap p erlak u a n . S etelah d id a p atk a n n asi in stan d e n g a n n ilai u ji ratin g
h ed o n ik y an g tertin g g i, m ak a d ilan ju tk an d e n g a n a n alisis p ro k sim at terh ad ap n asi in stan ters eb u t.
2 0 g N asi u d u k in stan
1 5 0 m l air d e n g a n s u h u
90 °C
T aru h d alam g elas tertu tu p d an tu n g g u s am p ai 5 m en it
N asi u d u k in stan siap d i san ta p
G am b ar 8 . S k em a reh id ra si n a si u d u k in sta n
3 .3
A n a lisis P r o d u k
3 .3 .1 .
R a sio R e h id ra si
C o n to h
seb any ak
10
gram
d im asu k k a n
ke
d alam
g ela s
p iala,
d itam b ah
dengan
15 0
m l
o
aq u a d e s. C o n to h k em u d ia n d im as u k k an k e w a te rb a th b ersu h u 8 0 C selam a 1 0 m en it. H asil p em as ak an
d ib iark an sam p ai m e n ca p ai su h u k am ar, k em u d ian d itim b an g b erat n asi y an g tela h d ireh id ra si s etelah
d i t i ri sk a n . R a si o r e h i d r a si ( R r ) d i h i t u n g d e n g a n r u m u s :
B erat n asi in stan setelah reh id rasi (g )
R r
=
B erat co n to h n a si in sta n (g )
3 .3 .2 .
R o n g g a K o so n g ( V o id S p a c e)
V o id sp a ce
in stan
ad ala h b e sarn y a ru an g
d im asu k k a n k e d alam
kosong
antar beras
d alam
w a d ah . B u tiran -b u tiran b eras
g ela s u k u r 2 5 m l sam p ai p e n u h , k em u d ia n d itam b ah k an to lu en s am p ai
b u tiran terseb u t tere n d am lalu d iu k u r v o lu m e to lu en y an g d ib u tu h k a n .
�
3 .3 .3 .
=
�
100%
�
U ji O rg a n o lep tik
N
= vo id sp a ce
V c
= v o lu m e cairan
V
= v o lu m e to tal
( A d a w iy a h D R d a n W a y sim a . 2 0 0 9 )
U ji o rg an o lep tik y an g d ilak u k an ad ala h u ji p en erim aan terh ad ap w arn a, aro m a, tek stu r, ra sa
d an citra k es elu ru h a n d im an a s etiap p a n elis d ih aru s k a n m en g em u k ak a n tan g g ap an p rib ad in y a terh ad ap
10
produk
yang
d isajik a n . U ji
p en erim aan
yan g
d ilak u k a n
ad alah
u ji h e d o n ik
yang
m en g g u n a k an 3 0 p an elis tid ak terlatih . S k ala h e d o n ic y an g d ig u n ak an ad alah 1
7=
S a n g at S u k a ; 6 = S u k a; 5 = A g a k S u k a; 4 = N etral; 3 = A g ak
T id ak
–
d ilak u k an
d eng an
7, di m an a ang ka
S u k a; 2 = T id ak S u k a; 1 = S a n g at
T id ak S u k a
3 .3 .4 .
K a d a r A ir
(SN I 01-39 45-199 5)
P en g u k u ra n d ilak u k an d e n g a n m en g g u n ak a n m eto d e o v en . C aw an k o so n g d ik erin g k a n d alam
o v en s elam a 1 5 m e n it d an d id in g in k a n d alam
y an g tela h d ik erin g k an d im as u k k an d alam
o
oven pad a suhu 105 C
ke
d e sik ato r, k em u d ia n d itim b an g . S e b an y ak 5 g ram
co n to h
ca w an y an g telah d itim b an g s elan ju tn y a d ik erin g k an d alam
selam a 6 jam , c aw an y a n g telah b erisi co n to h terse b u t sel an ju tn y a d ip in d ah k an
d esik ato r, d id in g in k an ,
dan
d itim b an g . P en g erin g an
d ilak u k an
sam p ai
d ip ero leh
berat
k o n sta n ,
k em u d ia n d ih itu n g b erd asark an k eh ilan g an b erat y aitu selisih b erat aw al d ik u ran g i b erat ak h ir.
�
�
�
�� ( %
�
��
%
−
) =
�
=
−
− (
−
∗ 100%
)
∗ 100%
−
a = B erat caw an k o s o n g k erin g ( g )
x = B erat sam p el aw al (g )
y = B erat caw an + sam p el k erin g
x = B erat sam p el b a sa h
K adar A bu ( SN I 01 – 3 945 – 1 995 )
3 .3 .5 .
C o n to h b era s d itim b an g s eb a n y a k 2 -3 g ram
k e d alam
caw an p o r selen y an g telah d ik etah u i
b o b o tn y a. A ra n g k an d i ata s n y ala p em b a k ar, lalu a b u k an d alam
o
550 C
tan u r listrik p ad a
su h u m a k sim u m
sam p ai p en g ab u an seles ai (sek ali - sek ali p in tu tan u r d ib u k a se d ik it ag ar o k sig e n b is a m a su k ).
D in g in k an d alam
d e sik ato r lalu d itim b an g h in g g a b o b o t tetap .
K adar a bu (% ) = x – a x 10 0%
w
a
= B erat caw an k o s o n g k erin g (g )
w = B erat s am p le aw al (g )
x = B erat abu + b erat caw an
3 .3 .6 .
K a d a r P ro tein d en g a n M eto d e K je ld a h l
S eba nya k
selen iu m
0 .2 5
0 .2 5 g r a m
gram
dan 3 m l H
sam p le,
2
SO
4
d im a su k k an
d alam
lab u
K jeld ah l
m l
dan
tam b ah k an
p ek at. K em u d ia n lak u k an d estru k si (p em an asa n d alam
m e n d i d i h ) s e l a m a 1 j a m , s a m p a i l a r u t a n j e r n i h .s e t e l a h d i n g i n t a m b a h k a n
N a O H 4 0 % ,l a l u d i d e s t i l a s i . H a s i l d e s t i l a s i d i t a m p u n g d a l a m
m l H 3B O 3 2%
100
d an 2 tetes in d icato r B ro m
kea da an
5 0 m l aq u ad est d a n 2 0 m l
lab u E rlen m ey er y an g b erisi cam p u ran 1 0
C re so l G re en -M eth yl R ed
b erw arn a m era h m u d a. S etelah
v o l u m e h a s i l t a m p u n g a n ( d e s t i l a t ) m e n j a d i 1 0 m l d a n b e r w a r n a h i j a u k e b i r u a n ,d e s t i l a s i d i h e n t i k a n d a n
d estilasi d ititrasi d en g an H C L 0 ,1 N
sam p ai b erw arn a m era h m u d a. P erlak u an y an g s am a d ilak u k an
ju g a terh ad ap b lan k o . D e n g an m eto d e in i d ip ero leh k ad ar N itro g en to tal y an g d ih itu n g d e n g a n ru m u s:
% N = (m l H C l – m l b lan k o ) x n o rm alitas x 1 4 x 1 0 0
m g sam p el
% P r o t e i n = % N x 6 ,2 5
3 .3 .7 .
K a d a r L em a k d e n g a n M eto d e S o x h let
S eba nya k
2
gram
sam pel
d ise b ar
di
atas
kapas
y an g
b eralas
k ertas
s arin g
d an
d ig u lu n g
m em b en tu k th im b le, lalu d im as u k k an k e d alam la b u so x h let. K em u d ian ek strak si selam a 6 jam , d en g an
11
p e l a r u t l e m a k b e r u p a h e k s a n s e b a n y a k 1 5 0 m l .L e m a k y a n g t e r e k s t r a k , k e m u d i a n d i k e r i n g k a n d a l a m
o v en p a d a su h u 1 0 0
0
C s elam a 1 jam .
% lem ak = B erat lem ak x 1 0 0
B erat co n to h
B erat lem ak = (b erat lab u + lem a k ) – b erat lab u
3 .3 .8 .
W a k tu R eh id r a si
S am p el y an g d ian g g a p terb aik d iam b il se b an y a k 2 0 g d itim b an g d an d ic am p u r d en g an 6 0 m l
air p ad a s u h u 9 0 ° C
teren d am
d i d alam
g ela s p iala 2 5 0 m l. W ak tu reh id ra si d iu k u r m u lai seja k s elu ru h s am p el
air p an a s s am p ai air terserap s em u a.
12
IV .
4 .1
H A S IL D A N P E M B A H A S A N
P e n e l i ti a n P e n d a h u l u a n
H asil d ari p en elitian p en d a h u lu a n
m en u n ju k k an b a h w a p erlak u an p em as ak an m en g g u n ak an
reto rt selam a 5 m en it m en g h a silk an n asi y an g k eras d an k u ran g m as ak . P em a sak an selam a 1 5 m e n it
m en g h asilk a n n asi y an g h an cu r a k ib at terlalu m a sa k . A d ap u n p em a sa k an d e n g an reto rt s elam a 1 0 leb ih
k u ran g s eta ra d alam p en am p a k an v is u al d en g an aro n k u k u s , k aren a itu h asil p em as ak an reto rt s elam a 5
d an 1 5 m e n it tid ak d ik erin g k an
d a n p erb an d in g an h a siln y a d ap at d ilih at p ad a T a b el 3 .
T ab el 3 . K arak teristik n asi h asil p em asa k a n d a n p en g erin g an
P erlak u a n
P en g am atan v isu al p ro d u k
1
L en g k et, tid ak b isa m en jad i b u tiran tu n g g al, b erw arn a a g ak k e co k lata n
2
L en g k et, tid ak b isa m en jad i b u tiran tu n g g al, b erw arn a k eco k latan
3
T id ak len g k et, b isa m en jad i b u tiran tu n g g al, b erw arn a a g ak k e co k lata n
4
T id ak len g k et, b isa m en jad i b u tiran tu n g g al, b erw arn a k eco k latan
K eteran g a n :
p erlak u a n 1 : b eras d im as ak m e n g g u n ak a n reto rt selam a 1 0 m en it d an d ik erin g k an p ad a s u h u 6 0 ° C
p erlak u a n 2 : b eras d im as ak m e n g g u n ak a n reto rt selam a 1 0 m en it d an d ik erin g k an p ad a s u h u 8 0 ° C
p erlak u a n 3 : b eras d im as ak m e n g g u n ak a n m eto d e aro n k u k u s d a n d ik erin g k an p a d a su h u 6 0 ° C
p erlak u a n 4 : b eras d im as ak m e n g g u n ak a n m eto d e aro n k u k u s d a n d ik erin g k an p a d a su h u 8 0 ° C
P em as ak an m en g g u n ak an reto rt m e n g h asilk a n b eras y a n g len g k et, seh in g g a s aat d ik erin g k an
m en g g u n a k an flu id ized b ed d r yer m e n g h asilk an b u tiran b era s y an g tid a k d ap at terp isah k aren a len g k et.
N asi
yang
le n g k et
terseb u t
d iseb ab k an
o leh
b eras
yan g
terg elatin isa si.
B era s
y ang
d im as ak
m en g g u n a k an reto rt m en g alam i g elatin isa si p ati y an g b erleb ih a n , k are n a tek an a n p a d a saat p em as ak an
terlalu
b esar
G elatin isasi
d an
pad a
m eny eb abk an
bera s
yan g
stru k tu r
d im as ak
sel
b eras
m en jad i
m en ggu nak a n
reto rt
rusak
dan
m en g ak ib atk an
m enyeb abk an
terjad in y a
len g k et .
p em asak an
b erleb ih an (o ve r c o o k ed ) .
B erd as ark an d ata ters eb u t, m ak a d ip ilih m eto d e p em as ak a n m e n g g u n a k an aro n k u k u s. P a d a
p em a sak an m en g g u n ak an m eto d e
aron
ku kus
d id ap ati b eras
y an g tid a k len g k et
dan
d a p at m en jad i
b u tiran tu n g g al sa at d ik erin g k an .
4 .2
P e n e l i ti a n U t a m a
4 .2 .1
R a sio R e h id ra si
G am b ar rasio reh id ra si (G am b ar
9 ) m en u n ju k k an seb erap a b e sar d a y a serap sam p el terh ad ap
air. D ata terseb u t m en u n ju k k an tin g k at p e n y era p an air n asi u d u k in stan setela h d ik erin g k an . D ik e tah u i
b ah w a s am p el d en g an p erlak u an p en g erin g an A m em ilik i rasio reh id ra si y an g p alin g tin g g i, y aitu 5 ,8 .
S am p el in i m em ilik i rasio
pada
sam p el
in i.
reh id rasi p alin g tin g g i d iseb ab k an p en g erin g an b ertah ap y an g d ilak u k an
P en g erin g an
b ertah ap
y ang
d ilak u k an
m en guran gi
resik o
ca se
h a r d en in g .
C a se
h a rd en in g m eru p ak a n fen o m en a terjad in y a p en g eras an p ad a b a g ian k u lit ak ib at p em an a sa n b erleb ih an
y an g m en y eb ab k an k eru s ak a n p a d a sel s eh in g g a m en g k eru t d a n air d alam
b ah an p an g an tid a k d ap at
k elu ar s ec ara s em p u rn a. M eto d e p en g erin g a n b ertah ap , m em u n g k in k an air p a d a b ah an
teratu r
m en in g g alk an
sam p el.
P e n g erin g an
b ertah ap
in i
m en g h asilk a n
b eras
k elu ar se cara
in stan
y ang
leb ih
m en g em b an g d ari p en am p ak an lu ar, b ila d ib a n d in g k an d e n g a n s am p el lain n y a.
S am pel
d eng an
p erlak u an
p en g erin g a n
B
m em ilik i
rasio
reh id rasi
4.
D ata
terseb u t
m en u n ju k k a n b a h w a sam p el in i m asih m em ilik i k em am p u an reh id ra si, m es k ip u n n ilain y a tid ak se b aik
sam p el p ertam a. P en y eb a b
Suhu 60
o
p erb e d aa n ra sio reh id ra si in i a d alah
suhu
p e n g erin g an
yang
d ig u n ak a n .
C y a n g d ig u n ak a n , seb en arn y a m asih m as u k p ad a re n tan g su h u p en g erin g a n n asi u d u k in sta n ,
n am u n p e n g e rin g an sec ara lan g su n g ak a n m e n g a k ib atk a n air y a n g ad a p ad a b ah an p an g an tid a k d ap at
13
k elu ar s ec ara s em p u rn a. A ir y an g tertin g g al p ad a b a h an p a n g an ak a n m e n u ru n k an rasio re h id rasi b ah an
p an g an ters eb u t.
S am pel
k etig a, ad alah
sam p el d e n g an p erlak u a n p en g erin g an
C . S am p el terseb u t m em ilik i
rasio reh id rasi y an g p alin g ren d ah . N ilai terseb u t d iseb ab k an air y an g b erad a d alam
terseb u t tid a k k elu ar
sec ara
sem p u rn a
d ise b ab k an
o leh
c a s e h a rd en in g
p ada
n asi u d u k in stan
b aha n p an gan
tes eb u t
ak ib at c ara p e n g erin g an y an g tid ak te p at.
8
5. 8
6
4
4
3
2
0
A
B
C
G am b ar 9 . R asio reh id rasi b eras h a sil p erlak u a n
R o n g g a K o so n g ( V o id S p a ce)
4 .2 .2
N ilai vo id sp a c e y a n g d id a p at p a d a p en elitian in i m en g g am b ark an ro n g g a a n tar b eras d alam
w ad ah . M ak in b e sar n ilai ro n g g a an tar b eras , m en u n ju k k an u k u ran b era s y an g m ak in b e sar. S em ak in
b es ar b u tiran b eras m en u n ju k k an n ilai p o ro sitas b era s y an g s em ak in b e sar. S am p el d e n g a n p erlak u a n A
m em ilik i
n il a i
rongga
an tar
beras
d ala m
m e m i l i k i n il a i r o n g g a a n t a r b e r a s d a l a m
w ada h
p alin g
tin g g i
seb es ar
6 1 .8 % . S a m p e l
w a d a h s e b e s a r 4 9 .8 % . P e r l a k u a n C
p erlak u an
B
m em ilik i n ilai p erlak u an
an tar b era s p alin g ren d ah y aitu 4 3 .2 % .
M elalu i d ata terseb u t d ik eta h u i b ah w a b eras d e n g an p erlak u an A m em ilik i ro n g g a y an g p alin g
b es ar d ian tara d u a s am p el lain n y a . R o n g g a a n tar b era s y an g b esar, m en u n ju k k an u k u ra n b eras y a n g
b es ar. U k u ra n b eras y a n g b e sar, m en u n ju k k an p o ro sita s b eras y a n g b e sar . P erlak u a n C
rongga
an tar
b era s d alam
w ada h
y an g k ecil. N ilai terse b u t m e n u n ju k k a n
ukuran
m em ilik i n ilai
b eras
yang
k ecil.
S e m a k i n k e c i l u k u r a n b e r a s , m e n u n j u k k a n k o n d i s i p o r o s i t a s y a n g k e c i l p u l a ..
B esarn y a n ilai ro n g g a y an g d id ap at, b erh u b u n g a n d en g an rasio reh id rasi. R o n g g a b eras y a n g
b es ar, ak an m en g h asilk an n ilai rasio reh id rasi y an g tin g g i. N ilai rasio reh id rasi y an g tin g g i, d iseb ab k an
b eras m em ilik i ro n g g a y an g b esar. S a at d ilak u k an p ro ses reh id ra si, b eras d e n g a n u k u ran ro n g g a y a n g
leb ih b e sar ak an le b ih b a n y a k m e n y era p air. P ad a p e rlak u a n A , m em ilik i p o ro sita s y a n g p alin g tin g g i.
S aat