The effect of thermal times of circulating non-fried roast technique on the formation of (non)volatile compounds in roasted mutton by multi-chromatography techniques and heat transfer analysis

The circulating non-fried roast (CNR) technology was firstly applied to roast mutton. The formation of (non)volatile compounds in the mutton roasted for 0-15 min was investigated. The samples roasted at varying times were discriminated using GC-O-MS and multivariate data analysis. A total of 40 volatile compounds were observed, in which 17 compounds were considered as key odorants with odor activity values (OAVs) higher than 1, such as dimethyl trisulfide and 2-ethyl-3,5-dimethylpyrazine. Composition and concentrations of volatile compounds were significantly changed during the process. The key nonvolatile compounds that contributed to flavor were 5'-inosine monophosphate (5'-IMP) and glutamic acid based on taste active values (TAVs) greater than 1. The reduced concentrations of most free amino acids and 5'-nucleotides decreased the equivalent umami concentrations (EUC). The higher thermal conductivity, lower thermal diffusivity and water activity were responsible for the formation of volatile compounds with increased roasting times. The CNR technology was an efficient tool to roast meat products.