Quality Characteristics of Frozen Soy Yogurt Prepared with Different Proteolytic Enzymes and Starter Culture

단백분해효소 전처리 및 starter culture의 종류에 따른 frozen soy yogurt의 품질특성

  • Lee, Jung-Eun (Department of Food & Nutrition, Chung Ang University) ;
  • Lee, Sook-Young (Department of Food & Nutrition, Chung Ang University)
  • 이정은 (중앙대학교 식품영양학과) ;
  • 이숙영 (중앙대학교 식품영양학과)
  • Published : 2001.12.01

Abstract

This study was carried out to evaluate the quality characteristics of frozen soy yogurts prepared with different proteolytic enzymes and starter culture. The viable cell counts of lactic acid bacteria in frozen soy yogurts were measured $10^8$ CFU/g by the single culture method, while $10^9$ CFU/g by the mixed culture method except ${\alpha}-chymotrypsin$ treatment. The viable cell counts of lactic acid bacteria did not decrease after freezing for 30 min in ice cream maker. The lactic acid bacteria from the mixed culture showed better bile acid tolerance than those from the single culture. The lactic acid bacteria from the frozen soy yogurt prepared with ${\alpha}-chymotrypsin$ and mixed culture of Bifidobacterium bifidum and Lactobacillus bulgaricus showed better acid tolerance and bile acid tolerance. The highest(73.45%) overrun was observed in the frozen soy yogurt treated with ${\alpha}-chymotrypsin$ and mixed culture of B. bifidum and L. bulgaricus. The melt-down percent was higher in the single culture than the mixed culture. In sensory test, the frozen soy yogurt prepared with ${\alpha}-chymotrypsin$ and mixed culture of B. bifidum and L. bulgaricus was the most desirable, the highest scores in sourness, bitterness and mouthfeel.