Effects of Heat Treatment of Soy Milk on Acid Production by Lactic Acid Bacteria and Quality of Soy Yogurt

두유(豆乳)의 가열처리가 젖산균의 산생성(散生成)과 대두요구르트의 품질에 미치는 영향

  • Ko, Young-Tae (Department of Foods & Nutrition, Duksung Women's University)
  • 고영태 (덕성여자대학교 식품영양학과)
  • Published : 1988.06.01

Abstract

The effects of various heat treatments of soy milk prepared from soy protein concentrate on growth and acid production by five species of lactic acid bacteria were investigated. Sensory property and sedimentation characteristics of soy yogurt prepared from heat-treated soy milk were also evaluated. Heat treatment of soy milk stimulated acid production by all cultures. Acid production was generally proportional to degree of heat treatment and acid production by all cultures except Streptococcus lactis was maximum in soy milk heated at $121^{\circ}C-1min$. However, viable cell count was not changed markedly by heat treatment of soy milk. Sensory property of soy yogurt beverage (SYB) prepared from soy milk heated at $95^{\circ}C-30min$ was better than that of unheated sample while sensory property of SYB prepared from soy milk heated at $121^{\circ}C-15min$ was inferior to that of unheated sample. Heat treatment of soy milk generally retarded sedimentation of curd in SYB.

Keywords

soy yogurt;soy protein concentrate;lactic acid bacteria