Enhancement of amino acid catabolism in Cheddar cheese using alpha-ketoglutarate: amino acid degradation in relation to volatile compounds and aroma character

The effectiveness of the transaminase acceptor alpha -ketoglutarate in enha ncing amino acid catabolism and manipulating the aroma profile of Cheddar c heese has been studied. Utilisation of alpha -keto glutarate, catabolism of amino acids, volatiles production, and aroma profile of the cheese were mo nitored after 6, 12 and 24 weeks ripening, Glutamate and GABA were consider ably enhanced on addition of the transaminase acceptor while levels of phen ylalanine. leucine, isoleucine, alanine, valine, methionine and threonine w ere reduced. Addition of alpha -ketoglutarate increased volatile components originating from the catabolism of branched chain and aromatic amino acids . These compounds included acetic, propanoic, 2-methylpropanoic and 3-methy lbutanoic acids, 3-methylbutanol. phenylacetaidehyde and benzaldehyde. Addi tionally enhanced production of 3-OH-2-butanone was evident. Addition of al pha -ketoglutarate increased aroma intensity, creamy and fruity aromas. Eff ects obtained must be verified by tasting cheeses made with food grade alph a -ketoglutarate, but results suggest potential benefits in accelerated mat uration, low fat systems and manipulation of flavour profiles. (C) 2001 Els evier Science Ltd. All rights reserved.