Influence of pasteurization and fat composition of milk on the volatile compounds and flavor characteristics of a semi-hard cheese

The effects of pasteurization and fat composition were studied simultaneous ly during the manufacture of experimental semi-hard cheeses. Two different fat compositions were obtained by collecting milk in the spring from cows t hat grazed pasture on farms located on the plain and from cows that were fe d hay on farms located in the mountains. Pasteurized milk was compared with raw milk, and creams from the two groups of cows were compared. The sensor y profile of all of the cheeses showed predominantly milky flavors. The raw milk cheeses had a more intense flavor than the pasteurized milk cheeses. This difference was supported by the profiles of volatile compounds. Raw mi lk cheeses were characterized by higher amounts of numerous alcohols, fatty acids, and sulfur compounds, and pasteurized milk cheeses were characteriz ed by higher amounts of ketones. These differences were related to the high level of indigenous microflora in raw milk cheeses. Alkenes were found to be more abundant in the cheeses from milk of cows grazing pasture and terpe nes were more abundant in the cheeses from milk of cows fed hay, but flavor differences between these cheeses were very slight.