CHANGES IN FLAVOR AND VOLATILES OF FULL-FAT AND REDUCED-FAT CHEDDAR CHEESES DURING MATURATION

To determine why reduced-fat (7% fat) Cheddar cheese does not develop full Cheddar flavour, volatiles from four manufactures of full-fat Che ddar (conventional and made by an ultrafiltration process) and reduced -fat Cheddars (1.5 and 2% salt, also made by the ultrafiltration proce ss) were compared at intervals over a 26-week period of maturation. Mo lecular distillates and headspace volatiles were examined by gas chrom atogr aphy/mass spectrometry. Headspace volatiles were also analysed f or sulphur compounds by gas chromatography with a flame photometric de tector. Full-fat cheeses consistently had more flavour than reduced-fa t cheeses. For each type of cheese the rate of production of dimethyl sulphide became progressively less as the season advanced. from lush s pring pastures to dry summer pastures. Overall, there was a steady inc rease with time of maturation in the level of H2S while the concentrat ion of methanethiol rose for the first 8 weeks and then levelled off. The concentration of sulphur compounds in the headspaces was greater g enerally for the reduced-fat cheeses than for the full-fat cheeses, bu t when partition coefficients are taken into consideration, the actual concentration of methanethiol in the reduced-fat cheese was about hal f that in the full fat cheese. There was a correlation of 0.82 between the intensity of Cheddar flavour and the concentration of methanethio l in the cheeses, indicating that a lack of methanethiol in the reduce d-fat cheeses was a major contributor to their lack of flavour. A comb ination of methanethiol and decanoic acid or butanoic acid in all chee ses gave a better correlation with Cheddar flavour than methanethiol a lone. Copyright (C) 1996 Published by Elsevier Science Limited