Identification of Chinese mitten crab volatile compounds based on MAE-SAFE-GC×GC/HR-TOFMS

Abstract:

Microwave-assisted extraction combined with solvent assisted flavor evaporation(MAE-SAFE) was applied to extract the volatiles from two edible parts of Chinese mitten crab, abdomen meat and gonad part. The volatiles were quantitatively analyzed by the comprehensive two-dimensional gas chromatography/high resolution-time of flight mass spectrometry (GC×GC/HR-TOFMS), and identified by the retention index with an aid of the NIST11 library. A total of 122 volatile compounds were identified, which is the largest identification number among similar researches of same material, and 60 compounds were double identified by the accurate mass (AM) determination. More aldehydes, ketones, nitrogen-containing compounds in gonad part with total of 108 compounds were identified, while only 75 volatiles were identified in abdomen meat. MAE-SAFE has a better effect on the extraction of polar thermo-sensitive volatile compounds than other volatile enrichment method, and 20 ketones, 27 alcohols, 7 nitrogen-containing compounds, 4 sulfur-containing compounds were identified. The gentle and rapid heating method ensures the authenticity of the aroma components. GC × GC/HR-TOFMS with high resolution and high peak capacities enabled isomeric compounds like (E) -2-penten-1-ol and (Z)-2-penten-1-ol to achieve full separation. Compounds like formamide (ammonia flavor), maltol (baking-like flavor) and its precursor 4H-2,3-dihydro-3,5-dihydroxy-6-methylpyran-4-one were first detected in Chinese mitten crab. Therefore, this study provides comprehensive and reliable volatile component information for subsequent screening of key aroma compounds.