Rennin 및 Starter의 첨가(添加)가 대두(大豆)치즈의 제조(製造) 및 숙성(熟成)에 미치는 영향(影響) = Effects of Rennin and/or Starter Addition on the Manufacture and Ripening of Soybean Cheeses

다국어 초록 (Multilingual Abstract)

This experiment was designed to optimize the process of manufacturing the soybean cheeses and to elucidate the chemical changes during ripening when the chemical changes during ripening when the milk components and enzyme preparations were added to the raw materials. Conditions for extracting soybean protein such as temperature, duration and amount of water added were determined; various coagulaters were compared by checking the curd texture and yield; starters from S. thermophilus, S. lactis MLB and S. cremoris EB-9 were tested as single- or multi-stain combinations; and the effects of skim milk and/or rennins-both microbial and calf origin-addition upon the process of manufacturing and ripening were studied. The results obtained were as follows. 1. optimal conditions for soybean extraction were found to be: temperature $100^{\circ}C$, duration 10 minutes, and amount of water added 9-fold, as considered the extraction rate of solids and proteins, and curd yield. 2. Sodium gluconate was the most effective among the coagulators tested, and 5% of single-strain starter from S. thermophilus was appered to be adequate inoculum for curd formation. 3. The effects of skim milk and/or rennins addition on the process of manufacturing and ripening of soybean cheeses were: 1) The addition of rennins resulted in fast formation of curd, especially with skim milk it was so. And Hansen rennet extracts brought better results in curd formation than Meito rennet extracts did. 2) No significant effect was observed on the changes in moisture content during ripening, however the levels of moisture contents in the products were higher in case of using Meito rennet extracts. 3) Effect on pH changes during ripening was also not significant in general, while levels of pH were decrease markedly during manufacturing and the initial stage of ripening. 4) The levels of bacterial counts were much higher in case of skim milk addition throughtout the ripening period. In general the numbers were reached to approximately $10^8cells/g$ during manufacturing, then decreased gradually to below $10^2cells/g$ in 8 weeks of ripening. 5) The addition of skim milk and/or rennin resulted in higher ripening index, and skim milk plus Meito rennet extracts was appeared to be best combination for the ripening index.