Lactobacillus acidophilus와 Propionibacterium freudenreichii로 혼합 배양한 Whey 발효물이 빵의 특성에 미치는 영향

Fermented Whey Produced by Mixed Culture of Lactobacillus acidophilus and Propionibacterium freudenreichii : Effect on Quality Properties of Bread

[ $10\%$ ] 유청배지에 Lactobacillus acidophilus와 Propionibacterium freudereichii를 혼합 배양할 때 유청 발효물 중의 생균수의 변화, 유당 소모량, 프로피온산과 초산생성량 등을 측정하였고, 유청 발효물을 식빵 제조에 일정량 첨가하여 식빵의 부피, 조직감, 보존성 등을 분석하였다. 4일 배양동안 L. acidophilus의 생균수는 배양 36시간에 $2.4\ties10^9$ cfu/mL, P. freudenreichii는 배양 96시간에 $9.42\times10^8$ cfu/mL로 최대값을 나타냈고 L. acidophilus가 P. freudenreichii보다 빠르게 증식하였다. 유당의 소모율은 $87.5\%$이었고, 4일 배양 후 프로피온산은 18.5g/L, 초산은 4.8g/L 생성되었으며 그 비율은 3.8:1이었다. 식빵의 부피는 유청 발효물을 많이 첨가할수록 작았으나 조직감은 유청 발효물이 많이 첨가될수록 낮은 경도 값으로 부드럽게 나타났으며, 보존성은 유청 발효물을 $10\%$첨가하였을 때 대조구에 비하여 2일 이상의 효과가 있는 것으로 나타났다.

A mixed Lactobacillus acidophilus and Propionibacterium freudenreichii was cultured in the $10\%$ whey broth with $0.5\%$ yeast extract for 4 days. Viable cell numbers of Lactobacillus acidophilus and Propionibacterium freudenreichii were $2.4\ties10^9$ cfu/mL after 36hr and $9.42\times10^8$ cfu/mL after 96 hr. Consumption rate of lactose during fermentation was $87.5\%$. Propionic acid was produced 18.5g/L and acetic acid was produced 4.8g/L, as a result of that, comparison of propionic acid and acetic acid was 3.8:1 Volume of white pan bread was decreased as added amount of whey was increased. Hardess of white pan bread was decresed as added amount of whey was increased. Preservation period of white pan bread with $10\%$ whey fermented product elongated 2 day compared to control.