Characterization and discrimination of the flavor profiles of Chinese indigenous sheep breeds via electronic sensory, smart instruments and chemometrics

Abstract

This study was conducted to analyze the flavor profile of six commercially available Chinese indigenous breeds of sheep meat and to distinguish them based on their flavor characteristics. Various techniques such as gas chromatography-mass spectrometry (GC-MS), electronic nose (E-nose), high performance liquid chromatography (HPLC) and electronic tongue (E-tongue) were employed to analyze both volatile and non-volatile compounds in the meat samples. The results showed that, a total of 28 volatile compounds in sheep meat were detected, with 1-octen-3-ol, 1-pentanol, hexanal, octanal, and nonanal identified as the major contributors to its aroma. Tan Sheep and Oula Sheep had significantly higher concentrations of 1-pentanol, nonanal, 1-octen-3-ol, 1-octanol, and hexanoic acid than other breeds. Sweet amino acids were the most abundant free amino acids, comprising 72–85% of the total FAAs, and inosinic acid was the most abundant ATP-related compound. Small-Tailed Han sheep had significantly higher levels of SFAAs, total FAAs, and AMP, while Tan sheep had significantly higher levels of UFAAs, and Oula Sheep had significantly higher levels of GMP. The response values of differential electronic sensors W5S, W1W, NMS, PKS, and SCS were found to be useful in discriminating between breeds of sheep meat. The fusion electronic sensory signals were used to train support vector machine and random forest models, both achieving 100% accuracy in discriminating between sheep breeds.