Volatile components, total phenolic compounds, and antioxidant capacities of worm-infected Gomphidius rutilus

This study evaluated the effects of worm infection on the volatile components, total phenolic compounds, and antioxidant capacities of Gomphidius rutilus. G. rutilus without worms (GW), G. rutilus infected by a small amount of worms (GS; infected area <50%), and G. rutilus infected by a large amount of worms (GL; infected area>50%) were investigated. The volatile components of G. rutilus were analyzed by simultaneous distillation-extraction (SDE) and headspace solid-phase microextraction (HS-SPME) using gas chromatography-mass spectrometry (GC-MS). A total of 17 and 19 types of volatile compounds were detected, including ketones, alcohols, benzene, alkenes, aldehydes, esters, acids, and alkanes. Alcohols comprised the most abundant compound in GL, GS, and GW. The relative content of 1-octen-3-ol was the highest in all mushrooms. The concentration of eight-carbon (C8) compounds relative to the total volatile compounds varied widely, ranging from 40% (GW) to 64.34% (GS) and 84.42% (GS) and to 91.59% (GL), respectively, among the three samples. The antioxidant capability and the total phenolic contents of G. rutilus were evaluated in this study. The highest total phenolic content (TPC) of 192.23 mg GAE/g was found in GL, which differed significantly (P < 0.05) from the latter two samples, whereas the lowest value of 156.11 mg GAE/g was found in GW. ABTS radical cation scavenging activity, FRAP ferric reducing antioxidant capacity (FRAP) radical scavenging activity, and oxygen radical absorbance capacity (ORAC) were investigated to screen the antioxidant properties of extracts. The contents of total phenolic compounds and their antioxidant capacities in vitro showed significant correlations (P < 0.01). Among the three types of samples, the phenolic compounds of GL exhibited the highest antioxidant capacity, showing the values of 0.089 mM TE/g for ABTS, 0.949 mM Fe2+ E/g for FRAP, and 1.952 M TE/g for ORAC. However, regarding the total antioxidant capacity, GS exhibited the highest antioxidant capacity, showing the values of 0.002648 mM TE/g for ABTS, 0.004437 mM Fe2+ E/g for FRAP, and 0.256 μM TE/g for ORAC. In conclusion, HS-SPME was more suitable for the extraction of volatile aroma components from G. rutilus. GL had the most abundant aroma components. GL had the highest TPC and antioxidant capacity compared with those of GS and GW, whereas GS showed the opposite results. Interestingly, GS was found to have the highest total antioxidant capacity in vitro. Based on these measured indicators, worm infection had no negative effect on the quality of G. rutilus. Therefore, worm-infected G. rutilus can also be consumed by humans.