Chemical and bacteriological characteristics of pichtogalo chanion cheese and mesophilic starter cultures for its production

Sixty-two samples of Pichtogalo Chanion cheese traditionally produced in Crete, a few (3 to 6) days old, were analyzed for some chemical and bacteriological characteristics. The results of physicochemical analyses were as follows: (1) moisture content 61.63% (standard deviation 4.67); (2) fat in dry matter 54.03% (SD 7.73); (3) protein content 14.23% (SD 1.72); (4) salt content 1.02% (SD 0.38); (5) water activity (a(w)) 0.990 (SD 0.003); and (6) pH 4.36 (SD 0.25). None of the samples yielded Salmonella spp. Listeria monocytogenes and coagulase-positive staphylococci were present in 6.45% of the samples. Bacillus cereus and sulfite-reducing clostridia were isolated from 14.51% and 40.32% of the samples, respectively. High populations of coliforms were determined in the cheese samples. In 11.3% of the samples, Escherichia coli was not detected, while 88.7% of the samples yielded E. coli most probable number levels from 1.32 to 5.66 log10/g. The log10 CFU/g counts of enterococci were 6.89 (SD 0.84), of yeasts 6.79 (SD 0.61), of molds 4.68 (SD 0.69), and of psychrotrophic bacteria 7.63 (SD 0.62). The log10 CFU/g counts of lactic acid streptococci and lactococci were 7.91 (SD 0.68) and of lactobacilli 8.11 (SD 0.65). Lactic acid bacteria, mainly mesophilic, were isolated and confirmed using API 50 CH test trips. A pasteurized mixture of ewe's and goat's milk was made into Pichtogalo Chanion cheese according to standard procedure at 23 degrees C, after the addition of 4% commercial mesophilic starter culture or 2%, 3%, and 4% starter culture of the isolated and confirmed lactic acid bacteria and the addition of rennet. Results of this work indicated that high quality of Pichtogalo Chanion cheese can be produced using a pasteurized mixture of ewe's and goat's milk and 4% (vol/vol) of mesophilic starter culture.