Abstract: The volatile organic compounds (VOCs) in Lentinus edodes at different maturity stages were identified by optimized headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (GC-MS) and analyzed by odor activity value (OAV) and partial least squares discriminant analysis (PLS-DA). The results showed that the optimal extraction conditions were as follows: 1.0 g of sample was extracted at 50 ℃ for 25 min and then the analytes adsorbed on the fiber were desorbed in the GC-MS injection port for 3 min. A total of 71 VOCs were identified in L. edodes, and there were significant differences in the types and contents of volatile compounds at different maturity stages (P < 0.05). Out of these, 18 VOCs that could be used as biomarkers to distinguish L. edodes at different maturation stages were selected by PLS-DA and variable importance in projection (VIP). Besides, 16 volatile compounds with OAV ≥ 1 were identified. Among these compounds, 1-octen-3-ol, 3-octanol, 1-octen-3-one, 3-octanone, benzeneacetaldehyde, dimethyl disulphide, dimethyl trisulphide, 2,3,5-trithiohexane, and 1,2,4-trithiohexane showed VIP greater than 1, thus making them the most significant differential volatile compounds among different maturity stages of L. edodes. This study provides a theoretical foundation for understanding the mechanism of aroma formation during the maturation process of L. edodes.

Key words: Lentinus edodes; maturity stage; aroma; volatile compounds; headspace solid-phase microextraction; gas chromatography-mass spectrometry; partial least squares discriminant analysis