Study of proteolysis, lipolysis and volatile profile of a traditional Greek goat cheese (Xinotyri) during ripening

摘要

The proteolytic, lipolytic changes and the volatile profile of Xinotyri goat's cheese (an artisanal variety produced in the mountains of Naxos, a Greek island of the Aegean Sea) were studied during ripening. The cheese underwent very limited proteolysis; generally the WSN %TN and TCA-SN %TN contents remained stable, while the PTA-SN %TN content increased a little. Both beta- and alpha(s1)-caseins were slightly degraded until the age of 22 days and then remained stable. Free fatty acids (FFAs) content increased considerably during ripening and the most abundant FFAs were oleic, palmitic, myristic, stearic and capric acid. A total of 114 volatile compounds were detected. The most abundant group isolated at day 90 were alcohols followed by acids, ketones and esters, comprised 31.91%; 25.22%; 16.38%; and 15.54% of total compounds, respectively. Ethanol, acetic acid and hexanoic acid ethyl ester were at the highest level at all stages of ripening.