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 hanseni i added at a level of 3.5 x 10(6) cells/ml was investigated at differe nt temperatures (10-30 degrees C), pH values (4.7-6.0), NaCl concentra tions (2.5-7.5% w/v), and times of incubation (5-15 clays). Pronounced growth was obtained amounting to 10(7)-10(9) cells/ml even at conditi ons combining the lowest temperature, the lowest pH and the highest Na Cl concentration. Pork fat was hydrolysed to an extent depending on th e environmental conditions. A quadratic polynomial model was developed describing the combined effects of environmental conditions on lipoly sis. Regression analysis of data indicated that temperature, pH and ti me of incubation at conditions of meat fermentation were all significa nt factors in controlling lipolysis whereas NaCl concentration at the levels studied had no significant effect. Lipolysis increased when tem perature increased. At 10 degrees C, lipolysis was very restricted eve n though growth was observed. An increase in pH resulted in higher lip olysis, the effect being most pronounced at high temperatures.