Pengaruh Konsentrasi Ragi dan Lama Fermentasi terhadap Mutu Tape Ubi Jalar Ungu untuk Diolah Menjadi Keripik Tape Ubi Jalar Ungu

Abstract

This study was aimed to determine the effect of yeast concentration and fermentation time on the quality of purple sweet potato tape to obtain the best treatment that is processed further into purple sweet potato tape chips. This research was conducted at the Food Material Analysis Laboratory and Biochemistry Laboratory of Food Technology Study Program, University of North Sumatra. This study used a factorial completely randomized design (CRD) with two factors, namely yeast concentration (0.5%, 1%, 1.5% and 2%) and fermentation time (2 days, 3 days, 4 days, and 5 days). The parameters analyzed on the tape were total acid, pH, moisture content, alcohol, total sugar, yield as well as organoleptic color, aroma, taste, texture and general acceptance. Parameters analyzed on purple sweet potato tape chips were moisture content, ash content, pH, total sugar, yield, fat content, protein content, and color index. The results showed that yeast concentration and fermentation time gave a highly significant effect on total acid, pH, water content, alcohol, total sugar, yield and organoleptic aroma, taste, and general acceptance, but gave a significant effect on organoleptic texture and had no significant effect on organoleptic color. The interaction between the two factors gave a highly significant effect on total acid, pH, water content, alcohol, total sugar, yield and organoleptic aroma and taste, and had no significant effect on organoleptic texture, color and general acceptance. The best treatment of sweet potato tape processed into chips was tape with a yeast concentration of 0.5% and a fermentation time of 2 days. The resulting purple sweet potato tape chips have a moisture content of 4.82%, pH 5.16, total sugar 21.14%, yield 38.29%, ash content 1.44%, protein 3.9%, fat 23.9% and color index 331.55 (purple color).