Regulation of taste-active components of meat by dietary branched-chain amino acids; effects of branched-chain amino acid antagonism.
1. The effects of dietary branched-chain amino acids (BCAAs) including leucine (Leu), isoleucine (Ile) and valine (Val) on taste-active components, especially free glutamate (Glu), in meat were investigated. 2. Broiler chickens (28 d old) were given varied dietary BCAA levels for 10 d before marketing. Dietary BCAA content ratios were either 100:100:100 (Low Leu group), 150:100:100 (Control group) or 150:150:150 (High Ile + Val group) for Leu:Ile:Val (% of each BCAA requirement according to NRC, 1994). Taste-related components of meat (free amino acids and ATP metabolites) and sensory scores of meat soup were estimated. 3. Free Glu content, the main taste-active component of meat, was significantly increased by dietary BCAA. Compared to the Control group, free Glu content increased by 30% in the High Ile + Val group. However, the inosine monophosphate (IMP) content in meat did not change among groups. 4. Sensory evaluation of meat soups showed that Control and High Ile + Val groups had different meat flavours. The sensory score of overall taste intensity was significantly higher in the High Ile + Val group. 5. These results suggest that dietary BCAA concentrations regulate free Glu in meat. Increasing dietary Ile + Val induces an increase in free Glu content of meat, improves meat taste and is more effective for increasing free Glu content in meat than decreasing dietary Leu level.
Graduate School of Science and Technology, Niigata University, Niigata, Japan.
M
M
Imanari
M
M
Kadowaki
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S
Fujimura
D000597:Amino Acids, Branched-Chain / Q000032:analysis* / Q000037:antagonists & inhibitors* / Q000097:blood; D000821:Animal Feed; D000818:Animals; D000831:Animals, Newborn; D002645:Chickens; D003116:Color; D003624:Darkness; D018698:Glutamic Acid / Q000032:analysis / Q000097:blood; D006799:Housing, Animal; D006801:Humans; D008027:Light; D008460:Meat / Q000592:standards; D018482:Muscle, Skeletal / Q000737:chemistry; D013649:Taste
D000597:Amino Acids, Branched-Chain; D018698:Glutamic Acid