Abstract/Summary

The aim of this work was to identify volatiles that contribute to the aroma of cooked cheese, including the role of fat content in their development during cooking. Volatiles and odorants in cooked mature Cheddar were identified using a combination of SPME (solid phase microextraction) /GC-O (gas chromatography - olfactometry) and SPME/GC-MS (gas chromatography – mass spectrometry). A selection of the odorants were quantitated in six cheeses, uncooked and cooked, (mature Cheddar, high-, medium- and low-fat mild Cheddar, mozzarella and Parmesan). Many compounds showed significant differences between cooked and uncooked cheese; Strecker aldehydes, pyrazines and furanones were all significantly higher in cooked cheeses than in uncooked cheese, while ethyl esters (key odorants in uncooked cheese) were not detected in any of the cooked cheese. Principle component analysis demonstrated that fat concentration in mild Cheddar was positively correlated with formation of potential odorants (the Strecker aldehydes, methanethiol, 2-methylketones and fatty acids) upon cooking. Potential lipid precursors for these compounds are discussed.