1) Among five lactic acid bacteria examined, Str. thermophilus and Str. diacetilactis produced remarkably greater amount of acids in soybean milk than Str. lactis, Str. cremoris and L. bulgaricus.
2) Soybean milk and skimmed dry milk were combined in the ratio of 7 : 3 and were carried out in lactic acid fermentation for 24 hours at optimum temperature. The result indicated that the yield of precipitation and protein content of it were the most, the moisture content was the least and curd structure formed was considered too hard.
3) Based on these and other results, following procedure was used for manufacturing: soybean milk and skimmed dry milk were combined in the ratio of 7 : 3, heated at 121℃ for 20 min., cooled, added Str. thermophilus as lactic acid starter and incubated for 24 hours and 37±1℃. The curd was cooked, hooped, and pressed for 24 hours, to the surface of which, Penicillium caseicalum and sodium chloride were spread. During ripening of the curd at 15℃ and 85∼90% RH for 21 days, Pen. caseicolum was highly developed after 7 days, pH was increased and proteolytie activity has reached to the peak point after 14 days. After 7 days of ripening total water soluble nitrogen, water soluble protein nitrogen and amino acids nitrogen were begun to increase. After 21 days of ripening total water soluble nitrogen, water soluble protein nitrogen and amino-N reached to 52%, 32% and 14% of total nitogen. In the soybean cheese, after 21 days of ripening, 17 or more kinds of amino acids were detected by two-dimentional paper chromatography. The product contained 63.2% of moisture, 17.5% of crude protein, 13.2% of crude fat, 2.8% of crude ash and 2.5% of sodium chloride.
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