논문 상세보기
pp.208-210
본 실험은 yoghurt의 제조시 저장성를 높이기 위한 열처리가 Yoghurt의 pH와 β-galactosidase activity와 생균수에 어떤 영향을 미치는가를 측정하였다. 열처리시 pH는 많은 변화를 보이지 않았으나 β-galactosidase activity 는 55℃에서 30분간 가열시까지는 거의 영향이 없었고, 70℃가열시는 5분후에도 많은 저하를 보이고 있었다. 생균수 측정에 있어 55℃에서 60분간 가열시 1/2배 정도의 감소를 보였으나 70℃에서 5분간 가열시에도 생균수의 현저한 변화를 보였고 20분간 가열시 생균수의 검출이 어려웠다.
In order to know the influences of heat treatment of yoghurt on pH, β-galactosidase and viable cells, yoghurt sample was made by general method with Lactobacillus bulgaricus and Streptococcus thermophilus, and the changes in pH, β-galactosidase-activity and viable cell-count were determined during heating at 55℃ and 70℃. The pH of yoghurt was not changed when the yoghurt was heated at 70℃, but at 55℃ it decreased slightly. The stability of β-galactosidase was not affected markedly by heat treatment at 55℃, but was rapidly inactivated at 70℃. The heat treatment of yoghurt at 55℃ had the halb of viable cell in 1 hour, but the heat treatment at 70℃ had considerable effect on viable cell in 5 minutes.
