Pengaruh Fermentasi Natural dan Fermentasi Lactobacillus casei Terhadap Karakter Fisikokimia Tepung Ubi Jalar (Ipomea batatas) Varietas Jago

Abstract

Sweet potato (Ipomea batatas) has considerable potencies to be developed to support food diversification in Indonesia. One of sweet potato variety is Jago. Jago variety has high yields with high starch content, and suitable to be used in flour and starch production. Fermentation can be done to increase physicochemical and functional quality of sweet potato flour. In this research, sweet potato Jago was fermented for 1, 2 and 3 days using natural fermentation and controlled fermentation with Lactobacillus casei. Then the physicochemical properties were analyzed. Analysis showed that the sweet potato flour with best functional quality was the flour which fermented using L. casei during 3 days (L3). This flour contained 11.42% moisture, 0.41% ash, 0.20% fat, 1.72% protein, and 86.24% carbohydrate. The water absorption index of this flour was 2.78 gr/gr, the water solubility index was 0.0009 gr/ml, swelling power was 10.36%, solubility was 0.21%, whiteness index was 88.30% and freeze-thaw stability was 59.64%. The RVA analysis showed that peak viscosity of L3 flour was 6395 cP, breakdown viscosity was 3931 cP, final viscosity was 4030 cP, setback viscosity was 1566 cP, pasting temperature was 75.75⁰C and the peak time was 6.93 minute.