Dominant microflora of Picante cheese: effects on proteolysis and lipolysis

Four species of bacteria (Enterococcus faecium and E. faecalis, Lactobacillus plantarum and L. paracasein and three species of yeasts (Debaryomyces hansenii, Yarrowia lipolytica and Cryptococcus laurentiU previously isolated from Picante cheese, were assayed for proteolysis and lipolysis. Milk type (caprine or ovine), ripening time (0 to 65 d) and concentration of NaCl (0 to 14 %(w/v)) have been assessed in terms of their effects upon in vitro curdled milk. Good evidence of proteolytic and peptidolytic activities was provided for Y. lipolytica, and at much lower levels for the other strains. Milk type, ripening time and content of NaCl appeared to be statistically significant processing factors in terms of proteolysis. Clear lipolytic activity was detected for Y. lipolytica, but release of free fatty acids to lesser extents was also observed for the other strains under study. Ripening time was statistically significant with regard to lipolysis but milk type was not. Lipolytic activities were strongly affected by presence of NaCl. According to experimental results, it is suggested that a mixed-strain starter for Picante cheese including L. plantarum, E. faecium (or E. faecalis,) and D. hansenii (and/or Y. lipolyticaj is of potential interest.