Abstract: Purpose: To discover the effect of processing temperature on the volatile composition of yellowfin tuna. Methods: An electronic nose was used to detect raw and thermally processed (70, 80, 90, 100, 120 ℃ and 150 ℃) yellowfin tuna samples. The data obtained were analyzed by principal component analysis (PCA). Moreover, raw, 95 ℃ processed and 150 ℃ processed yellowfin tuna samples were analyzed by headspace solid-phase micro-extraction and GC-MS. Results: The electronic nose signals of different samples showed a strong cluster property. A total of 52, 50 and 53 volatile compounds were identified in aw, 95 ℃ processed and 150 ℃ processed yellowfin tuna samples, respectively. Among these compounds, the predominant ones were aldehydes, hydrocarbons, alcohols, kotones and furans, which synergistically contributed to the characteristic flavor of yellowfin tuna. Conclusions: Raw yellowfin tuna contains a large amount of the off-flavor compounds 1-penten-3-ol and 1,5-octadien-3-ol. Thermal processing can result in a significant decrease in their relative contents but a significant increase in the contents of the aroma-active compounds long-chain aldehydes and furans. 2-Ethyl-furan and 2-pentyl-furan are responsible for the characteristic aroma of roast yellowfin tuna.

Key words: yellow fin tuna, electronic nose, gas chromatography-mass spectrometry (GC-MS), volatile components