PENGARUH PERLAKUAN AWAL (PRE-TREATMENT) TERHADAP KARAKTERISTIK KIMIA DAN FUNGSIONAL TEPUNG UBI JALAR UNGU (The Effect of Pre-treatment on Chemical and Functional Characteristics of Purple Fleshed Sweet Potato Flour) - Wiwin Daniah; Elisa Julianti; Ismed Suhaidi (Universitas Sumatera Utara, 2017)
ABSTRACT The purpose of this research was to find the effect of pre-treatment on chemical and functional characteristics of purple flesh sweet potato flour. This research was using randomized design with two factors, namely the pre-treatment (P): (soaking in 200 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 chemical parameters analyzed were moisture content, acidity degree, anthocyanin content and the functional parameters analyzed were water absorption, oil absorption, swellling power, solubility, and baking expansion. The results showed that the effect of pre-treatment had highly significant effect on the acidity degree and had no significant effect on the anthocyanin content, water absorption, oil absorption, swellling power, solubility, and baking expansion.The soaking time gave highly significant effect on moisture content and had no significant effect on the acidity degree, anthocyanin content, water absorption, oil absorption, swellling power, solubility, and baking expansion. Keywords: Pre-treatment, soaking time, sodium metabisulfite, sodium chloride, ascorbic acid, the purple flesh sweet potato flour. ABSTRAK Tujuan peneitian ini adalah untuk mengetahui pengaruh perlakuan awal (pre-treatment) terhadap karakteristik kimia dan fungsional tepung ubi jalar ungu. Penelitian ini menggunakan rancangan acak lengkap dengan dua faktor, yaitu perlakuan awal (P): (perendaman dalam larutan natrium metabisulfit (Na2S2O5) 2000 ppm, perendaman dalam larutan natrium klorida (NaCl) 2000 ppm, perendaman dalam larutan asam askorbat 2000 ppm) dan lama perendaman (L): (10 menit, 20 menit, 30 menit). Parameter kimia yang dianalisa meliputi kadar air, derajat asam, kadar antosianin dan parameter fungsional yang dianalisa meliputi daya serap air, daya serap minyak, swelling power, kelarutan, dan baking expansion. Hasil penelitian menunjukkan bahwa pengaruh perlakuan awal memberikan pengaruh berbeda sangat nyata terhadap derajat asam dan memberikan pengaruh berbeda tidak nyata terhadap kadar antosianin, daya serap air, daya serap minyak, swelling power, kelarutan, dan baking expansion. Lama perendaman memberikan pengaruh berbeda sangat nyata terhadap kadar air, serta memberikan pengaruh berbeda tidak nyata terhadap derajat asam, kadar antosianin, daya serap air, daya serap minyak, swelling power, kelarutan, dan baking expansion. Interaksi antara kedua faktor memberikan pengaruh berbeda tidak nyata terhadap kadar air, derajat asam, kadar antosianin, daya serap air, daya serap minyak, swelling power, kelarutan, dan baking expansion. Kata kunci: perlakuan awal, lama perendaman, natrium metabisulfit, natrium klorida, asam askorbat, tepung ubi jalar ungu