Abstract:
The changes in volatile components in Pacific oysters under temperature stress were investigated using multiple methods, including sensory evaluation, gas chromatography-ion mobility spectroscopy (GC-IMS), gas chromatography-mass spectrometry (GC-MS), and multivariate statistical analysis. The analysis was conducted under different temperature stress conditions (12, 22, and 32 ℃). Concurrently, survival rate and fatty acid content of Pacific oysters were determined. After 6 days of stress, the 12 ℃ group exhibited a 97.90% survival rate, accompanied by an increase in n-3 polyunsaturated fatty acid (PUFA) content. Sensory evaluation, GC-IMS, and GC-MS results indicated a decrease in the content of aldehydes associated with fishy flavor, including octanal, and an increase in the content of (E,Z)-2,6-nonadienal (12.15%), which associated with fruity flavor, providing a pleasant odor to Pacific oysters. In contrast, exposure to high temperature stress at 32 ℃ resulted in a decrease in survival rate to 26.00%, accompanied by a decrease in n-3 PUFA content from 46.07% to 39.59%. Concurrently, there was a considerable increase in the content of aldehydes associated with fishy flavor, such as saturated aldehydes, intensifying the fishy smell of Pacific oysters and resulting in a notable deterioration in quality. In other words, high temperature stress caused a serious decline in oyster quality. Statistical analysis revealed significant differences in six key volatile components: octanal, hexanal, (E,Z)-2,6-nonadienal, (E)-2-nonenal, (E,E)-2,4-heptadienal, and 3-octanone. The survival rate, n-3 PUFA content, and volatile component composition of Pacific oysters were remarkably influenced by temperature stress. This study provides a valuable reference for enhancing the quality of Pacific oysters.
