Lipolysis of pork fat by the meat starter culture Debaryomyces hansenii at various environmental conditions.

Lipolysis of pork fat by the meat starter culture Debaryomyces hansenii added at a level of 3.5 x 10(6) cells/ml was investigated at different temperatures (10-30 degrees C), pH values (4.7-6.0). NaCl concentrations (2.5-7.5% w/v), and times of incubation (5-15 days). Pronounced growth was obtained amounting to 10(7)-10(9) cells/ml even at conditions combining the lowest temperature, the lowest pH and the highest NaCl concentration. Pork fat was hydrolysed to an extent depending on the environmental conditions. A quadratic polynomial model was developed describing the combined effects of environmental conditions on lipolysis. Regression analysis of data indicated that temperature, pH and time of incubation at conditions of meat fermentation were all significant factors in controlling lipolysis whereas NaCl concentration at the levels studied had no significant effect. Lipolysis increased when temperature increased. At 10 degrees C, lipolysis was very restricted even though growth was observed. An increase in pH resulted in higher lipolysis, the effect being most pronounced at high temperatures.