Water soluble precursors of beef flavour. Part II Effect of post mortem conditioning英文电子书.pdf

Available online at MEAT SCIENCE Meat Science 79 (2008) 270–277 /locate/meatsci Water-soluble precursors of beef flavour. Part II: Effect of post-mortem conditioning G. Koutsidis a, J.S. Elmore a, M.J. Oruna-Concha a, M.M. Campo b, J.D. Wood b, D.S. Mottram a,* a Department of Food Biosciences, University of Reading, Whiteknights, Reading RG6 6AP, UK b Division of Farm Animal Science, School of Clinical Veterinary Science, University of Bristol, Langford, Bristol BS40 5DU, UK Received 27 July 2007; received in revised form 8 September 2007; accepted 20 September 2007 Abstract Changes in glycolytic metabolites, nucleotide degradation products, free amino acids and other amino compounds were monitored in beef muscle (M. longissimus lumborum), stored for 21 days at 4 C, in order to evaluate how post-mortem conditioning may affect flavour formation in beef. The major effects observed in sugar-related substances were the dephosphorylation of the phosphates of glucose, fruc- tose and mannose, to yield their free sugars, as well as the breakdown of inosine 50 -monophosphate, to give a sixfold increase in ribose. Total reducing sugars increased by only 15% during conditioning, while glycogen levels remained unchanged from 2 days post-slaughter. Free amino acids increased during conditioning, particularly between days