1970 Volume 17 Issue 10 Pages 456-461
Cultured milk products from skimmilk-soy milk combinations were fundamentally studied by inoculating pasteurized samples with lactic starter cultures and measuring the acidity and the degree of curd hardness after 8hr. incubation at 30° or 37°C.
Ten per cent dispersions were heated under the 3 conditions at 63°C for 30min, 75°C for 15min, and 80°C for 5min; and then cooled. The result indicated that the viscosity raised at the range 63°-80°C, raised markedly at 80°C. Sucrose added to samples accelerated the development of viscosity, but restrained at 80°C.
With six cultures of lactic acid bacteria, after 8hr of incubation, the acid production tended to be higher in certain skimmilk-soy milk combinations than in skimmilk, exept for one culture. However, the acid production in soy milk was lower than in samples containing 70% (v/v%) soy milk. In soy milk, the acid production of Streptococcus faecalis, Streptococcus thermophilus and Strepococcus laclis increased a little. In samples supplemented with glucose, the genus Lactobacillus and Streptococcus starter cultures differed in their response to the individual skimmilk-soy milk combinations. In all cases, and in all but Lactobacillus acidophilus, sucrose did not promote the acid production of lactic starter cultures.
At soy milk concentration 20-30% (v/v%), curd after storing 24hr at 4°C was soft;on the other hand, at concentration 65-75% (v/v%), the curd structure formed was considered too hard. Addition of sucrose to 10% dispersions generally lowered the curd tensions, but glucose raised the curd tension when Lactobacillus was used.
