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

This study examined the effects of water-based thermal processing at two temperatures (80℃ and 95℃) and three storage conditions (room temperature, frozen, and no-storage) on the physicochemical properties and volatile flavor compounds of dried abalone ( Haliotis discus hannai ♀ × H. fulgens ♂) prepared using hot-air drying. Physicochemical assessments included proximate composition, amino acid and fatty acid profiles, rehydration ratio, histological structure and texture properties. The results showed that higher heating temperature (95℃) significantly increased the levels of glycine (Gly), proline (Pro), and monounsaturated fatty acids (MUFAs), while reducing collagen content. In contrast, lower heating temperature (80℃) enhanced adhesiveness ( P  < 0.05). Frozen storage significantly lowered cholesterol levels, whereas room temperature storage decreased saturated fatty acids (SFAs) but increased hardness and chewiness ( P  < 0.05). Volatile flavor compounds were characterized using an electronic nose (E-nose), which revealed distinct differences among treatment groups, and headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME/GC-MS), which identified 24 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, while room temperature storage increased aldehydes and frozen storage reduced alkanes ( P  < 0.05). Odor activity value (OAV) analysis indicated that nonanal, 1-octen-3-ol and octanal were the key contributors to dried abalone aroma. Overall, thermal processing at higher temperatures and room temperature storage effectively enhanced the physicochemical qualities and flavor characteristics of dried abalone.