Exploration of the evolution and production of volatile compounds in grouper (Epinephelus coioides) during cold storage

Abstract

Microbial growth, protein degradation and lipid oxidation played an important role in the flavor of grouper during cold storage. In order to study the relationship between volatile compounds (VOCs) and microorganisms, proteins and lipids in grouper during cold storage, headspace-solid phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) was used to analyze the VOCs of grouper during cold storage. The total viable counts (TVC), Pseudomonas count, total sulfhydryl (SH) content, carbonyl content, TBARs, total free fatty acids (FFAs) content and free amino acids (FAAs) were measured. The results showed that the indicators related to microorganisms, proteins and lipids deteriorated to different degrees during cold storage. A total of 67 VOCs were identified in the grouper. After screening, 10 key VOCs were found, 8 of which had a negative odor and were highly correlated with the deterioration of grouper quality. Through further correlation analysis, the source of key VOCs was basically determined, and the main factors affecting VOCs production were determined to be microbial growth, followed by protein degradation and lipid oxidation. It laid a foundation for regulating the flavor formation of grouper during cold storage from the source in the future.