Pengaruh Perlakuan Awal (PRE-TREATMENT) Terhadap Karakteristik Fisikokimia Dan Fungsional Tepung Ubi Jalar Ungu

ABSTRAK

WIWIN DANIAH : Pengaruh perlakuan awal (pre-treatment) terhadap
karakteristik fisikokimia dan fungsional tepung ubi jalar ungu, dibimbing oleh
ELISA JULIANTI dan ISMED SUHAIDI
Tujuan penelitian ini adalah untuk mengetahui pengaruh perlakuan awal
terhadap karakteristik fisikokimia dan fungsional tepung ubi jalar ungu. Penelitian
ini menggunakan rancangan acak lengkap dengan dua faktor, yaitu metode
perlakuan awal (P): (perendaman dalam larutan natrium metabisulfit (Na2S2O5)
2000 ppm, perendaman dalam larutan natrium klorida (NaCl) 2000 ppm, dan
perendaman dalam asam askorbat 2000 ppm dan lama perendaman
(L): 10 menit, 20 menit, 30 menit). parameter yang dianalisa meliputi nilai warna,
densitas kamba, organoleptik warna dan aroma, indeks pencoklatan, kadar air,
daya serap air dan minyak, swelling power, kelarutan, dan baking expansion.
Hasil penelitian menunjukkan bahwa perlakuan awal memberikan
pengaruh berbeda sangat nyata terhadap nilai warna, indeks pencoklatan,
derajat asam dan memberikan pengaruh berbeda tidak nyata terhadap densitas
kamba, organoleptik warna dan aroma, kadar air, kadar antosianin, daya serap air
dan minyak, swelling power, kelarutan, dan baking expansion. Lama perendaman
memberikan pengaruh berbeda sangat nyata terhadap densitas kamba, indeks
pencoklatan, kadar air dan memberikan pengaruh berbeda tidak nyata terhadap

nilai warna, organoleptik warna dan aroma, derajat asam, kadar antosianin, daya
serap air dan minyak, swelling power, kelarutan, dan baking expansion. Interaksi
antara kedua faktor memberikan pengaruh berbeda sangat nyata terhadap indeks
pencoklatan dan memberikan pengaruh berbeda tidak nyata terhadap nilai warna,
densitas kamba, organoleptik warna dan aroma, kadar air, derajat asam, kadar
antosianin, daya serap air dan minyak, swelling power, kelarutan, dan baking
expansion. Tepung dengan perlakuan terbaik adalah metode perlakuan awal
perendaman natrium metabisulfit (Na2S2O5) 2000 ppm dan lama perendaman
20 menit. Kadar abu, kadar protein, kadar lemak, kadar serat kasar, kadar pati,
kadar amilosa dan amilopektin, total gula, dan gula pereduksi dari tepung ubi jalar
ungu terbaik dianalisa.
Kata kunci: perlakuan awal, natrium metabisulfit, natrium klorida, asam askorbat,
lama perendaman, tepung ubi jalar ungu

i
Universitas Sumatera Utara

ABSTRACT
WIWIN DANIAH: The effect of pre-treatment on physicochemical and functional
characteristics of purple flesh sweet potato flour, supervised by

ELISA JULIANTI and ISMED SUHAIDI
The purpose of this research was to find the effect of pre-treatment on
physicochemical and functional properties of purple flesh sweet potato flour. This
research was using completely randomized design with two factors, namely the
method of pre-treatment (P): (soaking in 2000 ppm sodium metabisulfite
(Na2S2O5), soaking in 2000 ppm sodium chloride (NaCl), soaking in 2000 ppm
ascorbic acid and soaking time (L): (10 minutes, 20 minutes, 30 minutes). The
parameters that analyzed were the color values, bulk density, organoleptic test of
color and aroma, browning index, moisture content, acidity degree, anthocyanin
content, water and oil absorption, swelling power, solubility, and baking
expansion.
The research showed that the pre-treatment had highly significant effect
on the value of the color, browning index, acidity degree and had no significant
effect on the bulk density, organoleptic test of color and aroma, moisture content,
anthocyanin content, water and oil absorption, swelling power, solubility, and
baking expansion. The soaking time gave highly significant effect on bulk density,
browning index, moisture content and had no significant effect on the value of the
color, organoleptic test of color and aroma, acidity degree, anthocyanin content,
water and oil absorption, swelling power, solubility, and baking expansion. The
interaction between the two factors had highly significant effect on browning

index and had no significant effect on the value of the color, bulk density,
organoleptic test of color and aroma, moisture content, acidity degree,
anthocyanin content, water and oil absorption, swelling power, solubility, and
baking expansion. The flour with the best treatment was using pre-treatment of
soaking in 2000 ppm sodium metabisulfite (Na2S2O5) and soaking time of
20 minutes. Ash content, protein content, fat content, crude fiber content, starch
content, amylose and amylopectin content, total sugar, and reducing sugar of the
best flour was analyzed.
Keywords: pre-treatment, sodium metabisulfite, sodium chloride, ascorbic acid,
soaking time, the purple flesh sweet potato flour

ii
Universitas Sumatera Utara