EFFECT OF RIPENING TIME AND THE COMBINATION OF EWE AND GOAT MILK ON THE MICROFLORA OF PICANTE CHEESE

Changes in the counts of total viable microorganisms, lactic acid bact eria, Enterobacteriaceae, staphylococci, and yeasts, as well as pH, sa lt content, total solids content, ash content, and a(w) of Picante wer e examined using ANOVA. Five equally spaced proportions of goat to ewe milk covering the range of 0 to 100% were tested, and the correspondi ng cheeses were sampled at increasingly spaced times over a 180-day ri pening period. Numbers of staphylococci and Enterobacteriaceae were ve ry high, especially in the first days and for cheeses made with a high er percentage of ewe milk. The major groups present throughout ripenin g were lactic acid bacteria and yeasts. Strains of lactobacilli were u biquitously present, and their disappearance between 130-180 days seem s to be related to the increase in NaCl content up to 12% (w/w). There was a notable increase in the levels of yeasts during the first days, and a significant decrease towards 130 days. Both milk composition an d ripening time had statistically significant effects in all microbiol ogical and physico-chemical variables measured, but milk composition a pparently did not cause significant differences in terms of overall or ganoleptic evaluation. Attempts to mathematically correlate the number s of microorganisms with time were successfully performed.