Dairy starter; 1: acid and flavor compounds production of some single strains.
1987
Resubal L.E. | Emata Q.C. | Celestino E.L. | Collado E.R.
Four types of milk medium (reconstituted skimmilk or RSM, cow, goat and carabao's milk), 3 storage periods (16 hr, 2 days and 5 days) and 5 strains (Streptococcus lactis, Streptococcus diacetilactis, Lactobacillus bulgaricus, Lactobacillus casei and Betacoccus cremoris) at the rate of 1% were tested on quality of dairy starter in a 4 x 3 x 5 factorial in an RCB design. Streptococcus lactis, Streptococcus diacetilactis and Betacoccus cremoris were incubated for 16 hr at room temperature (26-36 degrees Celsius) while Lactobacillus bulgaricus and Lactobacillus casei at 37 degrees Celsius. Percent lactic acid, lactose and pH were determined right after incubation and at 2 and 5 days of storage at refrigerated temperature (3-9 degrees Celsius). Reconstituted skimmilk had the highest lactose (12.2%)) and lactic acid (0.23%) contents but lowest pH (5.70). Fat content was highest with carabao's milk (7.24%) and lowest with RSM (0.06%). Storage period, type of milk medium and type of starter significantly (P<.05) affected acidity and pH. Lactose content was affected by starter culture and milk medium (P<.05) but not by storage period. Lactobacillus casei had the fastest rate of acid production, hence the lowest lactose content, when inoculated to 4 milk media at 5 days of storage. With this culture, the highest mean value of lactic acid was obtained with RSM (1.71%) hence the fastest lactose degradation rate, and 5 days of storage (1.53%).
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