Characterization of aroma dynamic changes during six developing stages of yellow cultivar Flammulina filiformis based on E-Nose, GC×GC-TOF MS, GC-IMS, and GC-O-MS

Abstract

The aroma volatiles of Flammulina filiformis (F. filiformis) had notably dynamic changes during various developing stages. However, the dynamic fingerprints of the overall aroma volatiles during mushroom development remained largely unknown in F. filiformis. The purpose of this study was to characterize the dynamic changes in the aroma volatiles of yellow cultivar F. filiformis using E-Nose, GC-MS/O, GC-IMS, and GC × GC-TOF MS. A total of 140 volatiles were characterized (about 59% by GC × GC-TOF MS). Phenylacetaldehyde, 2-octenal, hexanal, nonanal, 2,4-decadienal, β-citronellol, 3-octanone, 1-octen-3-one, 2-methylpropyl butanoate, limonene, and 2-pentyl-furan were identified as key aroma compounds. The richness of odorants (numbers and concentrations) was most abundant during the initial stage of fruiting (with a fruity note). The concentrations of C8 volatiles and ketones gradually decreased before the mature stage, followed by a slight increase (with mushroom and sweet notes). An excellent correlation was observed between the changes in aroma attributes corresponding to odorants. Furthermore, the correlation between the volatile contents could be well explained by metabolic pathways (unsaturated fatty acids, β-oxidation of saturated fatty acids, and Ehrlich pathways for amino acids). Overall, this study provides insights into the metabolic pathways of volatiles potential for aroma quality enhancement in F. filiformis.