Proceeding of 2013 International Seminar on Climate Change and Food Security ISCCFS 2013
Palembang, South Sumatra -Indonesia, 24-25 October,2013
137 X
2.1
= 75 C ; X
2.2
= 80 C ; T
2.3
= 85 C ; T
2.4
= 90 C and T
2.5
= 95 C.
X
3
= Storage time hours : X
3.1
= 0 hour control; X
3.2
= 6 hours ; X
3.3
= 12 hours ; X
3.4
=18 hours ; X
3.5
= 24 hours; X
3.6
= 30 hours; X
3.7
= 36 hours ; X
3.8
= 42 hours and X
3.9
= 48 hours. Procedure:
a. Pempek dough processing was based on their formulations by addition of water and 2.5 table salt.
Water addition was conducted according to the following formulation :75 dough weight – fish water
content x fish weight – flour water content x flour weight.
b. Weighing of 350 grams pempek dough followed by pempek molding in cylindrical form which was then
boiled within water bath at temperature of 100 C. Temperature measurement on pempek was conducted
by using thermocouple line of K-type chromel + and allumel - installed on sample container during boiling. The use of thermocouple line was to guarantee that sample temperature measurement was at
pempek center point. Samples that had achieved center point temperature of 75 C, 80
C, 85 C, 90
C and 95
C were raised and leaked through. c.
The cooked pempek based on its center point temperature was then leaked through and stored at room temperature. The pempek deterioration was observed every 6 hours through textural change elasticity
by using
texture analyzer
, color change by using Munsell system, pH AOAC, Total Volatile Nitrogen TVN by using AOAC method and Total Microbes TotalPlate Count. TPC.
3. Result and Discussion
3.1. Colour
The research results showed that fish formulation produced pempek with lower lightness value achromatic color or color brightness, whereas chroma color intensity and hue chromatic color values
were higher. The longer the storage time, the lower was the lightness value but chroma and hue values wer higher. Measurement results of pempek lightness color brightness were in the range of 53.3 to 75.5 and
their values were decreased after 48 hours storage in the range of 46.4 to 61.0. Lightness or achromatic color within the rangeof 0 to 25 was black, within the rangeof 25 to 70 was dark grey, within the rangeof 70 to 80
was light grey and within the rangeof 80 to 100 was white Soekarto, 1990. The effect of formulation, temperature and shelf life on the change of pempek color was described by the following model :
Y = 86,382 + 3,981X
1
– 0.379X
2
– 0,228X
3
R
2
= 0,952.....................................................1 Pempek storage subsequently decreased its color brightness or lightness. According to Haryadi 1995, flour
gel during storage gradually became blur and turbid which was followed by deposition
retrogradation
. According to Kang 2007, the color brightness of fish gel kamaboko was also determined by fish
freshness. Measurement results of pempek chromatic color hue were in the range of 53.0to64.8 and their values
were increased after 48 hours storage in the range of 69.0to77.2. The effect of formulation, temperature and shelf life on the change of pempek chromatic color hue was described by the following model :
Y = 44,667 – 2,506 X
1
+ 0,230X
2
+ 0,290 R
2
= 0,968 ............................................................2 The chromatic color hue represents true color such as red, violet andyellow. Hue is usedto differentiate
colors and to determine redness, greenness etc. as well as related to light wavelength. Hue has value in the range of 0 to 360 degree with spectrum as follows : 0 degree red, 60 degree yellow, 120 degree green,
180 degree blue, 240 degree purple and 360 degree reddish purpleSoekarto, 1990.
Measurement results of pempek color intensity chroma were in the range of 4.0to6.8 and their values were increased after 48 hours storage in the range of 4.8 to 8.3. The effect of formulation, temperature and
shelf life on the change of pempek color intensity chroma was described by the following model : Y = 1,754
– 0,700 X
1
+ 0,60 X
2
+ 0,27 X
3
R
2
= 0,972............................................................3 Chroma or color intensity is color level based on its sharpness which has function to define the color of
an object that tend to be pure or dirty gray. The color intensity or chroma represents intensity of chromatic color that have values in the range of 0 colorless to 10 colorfull.
Proceeding of 2013 International Seminar on Climate Change and Food Security ISCCFS 2013
Palembang, South Sumatra -Indonesia, 24-25 October,2013
138
3.2. Texture elasticity
