Pengaruh Metode Perlakuan Awal (Pre-Treatment) dan Suhu Pengeringan terhadap Mutu Fisik, Kimia, dan Fungsional Tepung Ubi Jalar Oranye

Abstract

The purpose of this research was to find the effect of pre-treatment method and drying temperature on physical, chemical, and functional of orange flesh sweet potato flour. This research was using randomized design with two factors, namely the method of pre-treatment (P): (sweet potato unpeeled and slice, sweet potato peeled and slice, sweet potato unpeeled then slice and soaking in sodium metabisulfite (Na2S2O5) 0,5 %, sweet potato peeled then slice and soaking in sodium metabisulfite (Na2S2O5) 0,5 % and the drying temperature (T): (50 oC, 55 oC, 60 oC, 65 oC). The parameters that analyzed were the color values, bulk density, organoleptic test of color and aroma, browning index, moisture content, and 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, organoleptic test of color and aroma and moisture content, had significant effect on the absorption of oil, had no significant effect on the bulk density, browning index, water absorption, swelling power, solubility, and baking expansion. The temperature of drying gives highly significant effect on organoleptic test of color, browning index, and moisture content, had no significant effect on the value of the color, bulk density, organoleptic test of aroma, water and oil absorption, swelling power, solubility, and baking expansion. The interaction between the two factors had significant effect on moisture content and had no significant effect on the value of the color, bulk density, organoleptic test of color and aroma, browning index, water and oil absorption, swelling power, solubility, and baking expansion. The flour with the best treatment was using pre-treatment of sweet potato unpeeled tuber and soaking in sodium metabisulfite (Na2S2O5) 0,5 % and the drying temperature of 60 °C. β-carotene, ash content, protein content, fat content, crude fiber content, total sugar, reducing sugar, starch content, amylose and amylopectin, dextrose equivalent, the degree of polymerization, and vitamin C content of the best flour was analyzed.