Effects of thermal processing and storage on physicochemical properties and volatile flavor compounds of dried abalone (Haliotis discus hannai♀ × H. fulgens♂)

This study investigated the effects of water-based thermal processing at 80 and 95 ℃ and 3 storage conditions (room-temperature, frozen, and non-storage) on the physicochemical properties and volatile flavor compounds of dried abalone (Haliotis discus hannai♀ × H. fulgens♂) prepared using hot-air drying. Physicochemical evaluations included proximate composition, amino acid and fatty acid profiles, rehydration ratio, histological structure and texture properties. The results showed that thermal treatment at 95 ℃ significantly increased the levels of glycine, proline, and monounsaturated fatty acids, while reducing collagen content. In contrast, lower heating at 80 ℃ significantly enhanced adhesiveness (P < 0.05). Frozen storage notably decreased cholesterol content, while room-temperature storage reduced saturated fatty acids but increased hardness and chewiness (P < 0.05). Volatile flavor compounds were characterized using an electronic nose, which revealed distinct aroma profiles among different treatment groups, and headspace solid-phase microextraction gas chromatography-mass spectrometry, which identified 24 volatile compounds: 7 aldehydes, 5 alcohols, 2 alkenes, 7 alkanes, 1 ester, 1 ketone, and 1 furan. High-temperature processing elevated the levels of alcohols, aldehydes, and ketones, whereas room-temperature storage increased aldehydes and frozen storage reduced alkanes (P < 0.05). Odor activity value analysis indicated that nonanal, 1-octen-3-ol and octanal were the key flavor compounds. Overall, heating at 95 ℃ enhanced specific physicochemical and flavor-related attributes, including amino acids, fatty acids, and volatile compounds, while room-temperature storage promoted aldehyde accumulation but also resulted in increased hardness and chewiness.