Abstract:
In this study, headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) was employed, in conjunction with principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), and odor activity value (OAV), to systematically investigate the composition and differential distribution of volatile flavor compounds in the pileus, indusium, and stipe of dried
Dictyophora rubrovolvata. The results demonstrated that a total of 151 volatile compounds were identified, encompassing 11 types of substances such as esters, terpenes, and ketones. Notable variations were observed in both the types and contents of volatile compounds across the three morphological parts. Specifically, the contributions of the indusium and stipe to the overall flavor profile were significantly greater than that of the pileus.PCA and PLS-DA analyses confirmed that the volatile flavor compounds in the three regions exhibited significant compositional differences, enabling effective differentiation.PLS-DA jointly screened 57 differential compounds with VIP>1, primarily comprising alcohols, terpenes, and hydrocarbons. Combined OAV value analysis revealed five volatile flavor compounds common to all three parts with OAV>1 but VIP<1: (E,E)-3,5-octadien-2-one, (E,E)-2,4-nonadienal, 1-nonanol, trimethyloxazole, and 2-pentyl acetate. They were recognized as the key shared flavor substances among the three parts and serve as the core volatile flavor compounds that define the basic flavor keynote of dried
Dictyophora rubrovolvata. Comparing the specific key flavor compounds with OAV > 1 and VIP>1 across different parts, the cap contain (Z)-6-nonen-1-ol, imparting umami and grassy notes; The indusium contained trans, cis-2,6-nonadien-1-ol, 4,4-dimethyl-2-pentanone, 4,5-dichloro-2-methoxyphenol, and (Z) -6-nonen-1-ol. The first three substances could serve as key flavor compounds that distinguish indusium from other parts; The stipe contained ethyl 3-cyclohexenecarboxylate, which imparted cucumber and grassy aromas to the stem. This compound was a high-contribution component and could serve as a key flavor identifier for the stipe. The findings of this study provide a theoretical foundation for quality-oriented breeding, part-specific processing, and flavor modulation of
Dictyophora rubrovolvata.