Identification of the deterioration flavor markers based on E-nose, GC-IMS and GC-MS during fresh sea cucumber storage and preservation by thymol.

The freshness in A. japonicus after thymol treatment was tested. The results showed that sensory scores in thymol group significantly increased 14.83 and 21.67 compared to the Frozen and BK groups after storage. Texture parameters showed that hardness, springiness, and chewiness of body wall treated with thymol were 2.56, 1.21, and 2.02 folds that of the BK group, respectively. Volatile flavor results revealed 38 flavor substances and 33 volatile organic compounds in the body wall. Aldehydes, alcohols, heterocycles, and alkane were the key sources to odor components of A. japonicus, including nonanal, hexanal, 1-octanol, 1-hexanol, d-limonene, and 2-methylbutyl acetate. Moreover, heptenoic acid, dimethyl disulfide, and dimethylamine, as distinct volatile flavor substances, were the main contributors of fishy, malodorous, and spicy smells of autolysis A. japonicus. This study guides the potential use of thymol in sea cucumber preservation and seeks the spoiled flavor markers for non-destructive rapid testing technology development.