Electronic Theses and Dissertation

Abstract one of the most important ways to use bean is by producing it for fresh, durable, and health drink called soyhurt. soy ghurt is a fermented product of bean by using streptococcus thermophillus and lactobacillus bulgaricus bacteria which has generally been used in producing yoghurt. soyghurt is produced by inoculating streptococcus thermophillus and lactobacillus bulgaricus bacteria and adding some sugar as a substrate at less than 42" c degrees for six hours, so it will reach the same similarities needed. the purpose of this research is to know the effects of adding some starter, and substrate percentages against lactate acids, acid degrees (ph), grease, and protein received. from the deep analysis, it is known that the more increased substrate can decrease bacterium activities that produce lactate acid, grease, and protein. through this observation, it is found that the highest increases of grease is around 0,226% and the highest protein content gotten is around 4, 31% at the additional substrate of 3% wt and starter is 4% wt; the highest lactate acid received is around 1,845% at additional substrate of 3% wt and the additional starter 10% wt which produce the lowest ph values around 4. key words: soyghurt, lactobacillus bulgaricus, and streptococcus thermophillus bacteria