Metabolomic profiles and compositional differences involved in flavor characteristics of raw breast meat from slow- and fast-growing chickens in Thailand

This study aimed to differentiate the flavor characteristics of raw chicken breast meat from Thai slow-growing breeds (NC: native chicken, and KC: Korat/crossbred chicken) and fast-growing broilers (BR: broiler chicken) by using NMR-based metabolomic approaches along with multivariate data analysis. Chemical compounds related to chicken's flavor including free amino acids (FAA), ATP and its related compounds, sugars, as well as volatile compounds (VOC), were also investigated. BR had the highest total FAAs, followed by NC and KC (P < 0.05). In contrast, the accumulations of ATP degradation products, particularly ADP and IMP, were found at higher levels in the NC and KC (P < 0.05), while the highest total reducing sugars were noted in the KC (P < 0.05). Most VOCs found in the fresh breasts were products from the degradation of lipids, especially through lipid oxidation, which was found in varied types and proportions among samples. Not only chemical compounds but varying amounts of metabolites among samples were also detected. Apart from 21 identified metabolites, Glu, Gln, and betaine were the most prevalent in all samples with VIP > 1.00. Among 19 metabolic pathways, the most important pathways (P-value < 0.05, FDR < 0.05, impact > 0.05) were discovered to differentiate the flavor of raw chicken breast meat from various breeds. These metabolic pathways included (1) Ala, Asp and Glu metabolism; (2) D-Gln and D-Glu metabolism; (3) Purine metabolism; (4) β-Ala metabolism; (5) Aminoacyl-tRNA biosynthesis; (6) Nicotinate and nicotinamide metabolism; (7) Pyrimidine metabolism. Interestingly, based on the principal component analysis plot and partial least square-discriminant analysis (R