Characterization of the pattern of development of key compounds contributing to aroma quality of chicken meat and their metabolic markers

Abstract

Age has an important effect on the aroma of chicken meat. In this study, we systematically analyzed the patterns of aroma changes with increasing age and the key aroma-contributing compounds and metabolites that lead to aroma differences with age. Electronic nose (e-nose) and gas chromatography-mass spectrometry analyses showed that the overall aroma intensity and the types and levels of volatile aroma compounds increased with age. Eight key aroma-contributing compounds were identified by GC-olfactometry (GC-O) and odor activity value analyses, and their content increased with age. The e-nose and GC-O results revealed that 315-day-old chickens had the strongest aroma. Thus, taking 315-day-old chickens as reference, we found that the contents of key aroma-contributing compounds and metabolites at 140 days of age were most similar to those at 315 days of age. Due to low feed cost, yellow chickens around 140 days of age were more suitable for marketing in terms of volatile aroma substances. It was found that hexanal, 1-octen-3-ol, and (E,E)-2,4-decadienal contributed the most to chicken aroma. Additionally, small peptides were found to be the main types of metabolites responsible for the aroma difference in chickens due to age. Weighted gene co-expression network analysis identified Ile-Ser, Ile-Thr, and Phe-Ile as metabolic markers of hexanal and 1-octen-3-ol, respectively. Further analysis revealed that Ile-Ser, Ile-Thr, and Phe-Ile may promote the Maillard reaction by acting as substrates on the one hand, and facilitating the uptake of amino acids on the other hand, which in turn increases the contents of hexanal and 1-octen-3-ol.