Fat-Derived Volatiles of Various Products of Cows', Ewes', and Goats' Milk

Abstract

Raw milks and various dairy products from cows', ewes', and goats' milk were analyzed for fat-derived volatiles by headspace solid phase micro extraction-gas chromatography/mass spectrometry. In most products analyzed, free fatty acids of chain C4–C18, several carbonyl compounds, and lactones were detected. Moreover, acetic acid—a non fat-derived free fatty acid—and several ethyl esters were detected in some products. Raw cows', ewes', and goats' milks exhibited some qualitative and quantitative differences in their volatiles. Pasteurized cows' milk with 3.5% fat exhibited higher levels of most volatiles than that with 1.5% fat, while that with 0% fat exhibited the lowest levels. Only a few qualitative differences were observed among cultured milk and cows' and ewes' yoghurt, while the two yoghurts exhibited some quantitative differences. Levels of most volatiles decreased by decreasing the fat content of strained yoghurt (8.1, 2.1, and 0% fat). Cow and ewe sweet cream butters exhibited some differences in their volatiles. Twenty-day-old feta cheese exhibited higher levels of fat-derived volatiles than the ripened one (60 days old). Cow Gruyere-type cheese, ewe Gruyere-type cheese, and a goat semi-hard cheese exhibited qualitative and quantitative differences in their volatiles. Ewe and goat cheeses contained several ethyl esters, while cow cheese did not.