Reduction of dietary lysine increases free glutamate content in chicken meat and improves its taste

Taste is a crucial factor of meat quality, and amino acids are important taste‐active components in meat. Here, the effects of dietary lysine (Lys) content on taste‐active components in meat, especially free glutamate (Glu), were investigated. Twenty‐eight‐day‐old broilers (Gallus gallus) were fed diets with graded Lys content of 90% or 100% of the recommended Lys requirement, (according to the National Research Council, 1994 ) for 10 days. Free amino acid content in meat and sensory scores of meat soup were estimated. Free Glu content, the main taste‐active component of meat, was significantly increased by a reduction of dietary Lys. Compared with the Lys 100% group (control), free Glu concentrations of meat were increased by 35.7% in the Lys 90% group (P < 0.05). In addition, free glycine, valine, isoleucine, leucine, histidine and threonine concentrations of meat were significantly increased in the Lys 90% group (P < 0.05). Sensory evaluation of meat soup made from the Lys 100% and 90% groups indicated different meat tastes. Sensory scores of taste intensity, umami and kokumi tastes were significantly higher in the Lys 90% group. These results suggest that a reduction of dietary lysine increased free glutamate content in meat and improved its taste.