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.
Imanari
M
M
Graduate School of Science and Technology, Niigata University, Niigata, Japan.
Kadowaki
M
M
Fujimura
S
S
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