Effects of Different Processing Methods on the Volatile Components and Antioxidant Ability of the Water Extracts from Stropharia rugosoannulata

This study was aimed to compare the effects of thermal treatment (70, 90 ℃) and non-thermal treatment (room temperature, ultrasound treatment, homogenization and high hydrostatic pressure) on the volatile flavor of water extracts of Stropharia rugosoannulata with different particle sizes. Gas chromatography-mass spectrometry and electronic nose were applied to compare these volatile components, and the results indicated that the original mushroom powder without superfine grinding displayed the strong volatile flavor, and the sequence of the corresponding processing technology was followed as: Ultrasound treatment > high hydrostatic pressure > room temperature > homogenization > 70 ℃ > 90 ℃. There were 47 volatile components were identified in those water extracts of 18 S. rugosoannulata. Among them, hexanol, 1-octen-3-ol and hexanal were dominantly existed, and the sum of these three accounted for 75.02%~95.70% of the total volatile components. Under thermal treatment, the peak area of total volatiles in the water extracts of S. rugosoannulata ranged from 819.96×10⁶ to 4727.72×10⁶, while they were accounted for 4063.37×10⁶~8772.13×10⁶ in these non-thermal treated extracts, displayed more intense flavor. Both processing method and the particle size had a significant impact on the antioxidant capacity of the water extract of S. rugosoannulata (P<0.001). Thermal treatment combined with superfine pulverization reduced the free radical scavenging ability (DPPH, ABTS) of the water extract of S. rugosoannulata, but improved its iron ion reduction (FRAP) ability. This research might provide useful reference for the intensive processing of S. rugosoannulata in the seasoning market.