Microwave Treatment for Dictyophora rubrovolvata in Regulating Postharvest Autolysis and Energy Metabolism

Abstract

The shelf life of Dictyophora rubrovolvata (D. rubrovolvata) has been strongly limited by autolysis, a natural process of self-degradation. Conventional heat treatment methods (hot water or hot air) are not suitable for D. rubrovolvata fruiting bodies because of their fragile and porous structure. Therefore, in this work, we attempted to use microwave treatment (MT/100 W, 75 W, 50 W) to delay autolysis and extend the shelf life of D. rubrovolvata fruiting bodies. The results showed that MT could delay the decrease in cellulose, chitosan, and β-1,3 glucan contents by inhibiting the corresponding enzyme activity and maintain a high level of energy chargeby delaying the decrease in ATP and ADP. Meanwhile, compared with control group (CK), D. rubrovolvata fruiting bodies after MT had improvements in many qualities during storage (4 ℃, 95 % RH), including delayed deterioration of water migration, sensory evaluation, browning, shear force, ethanol, malondialdehyde (MDA), relative conductivity and respiratory rate. Furthermore, D. rubrovolvata fruiting bodies after MT maintained contents of umami compounds compared to CK, which included free amino acids, 5′-Nucleotides and equivalent umami concentration (EUC). The electronic nose (E-nose) results showed that MT maintained a better avour. Notably, the effect of low power (50 W) was better than that of high power (100 W, 75 W). Thus, microwaves could effectively regulate autolysis and energy metabolism of D. rubrovolvata fruiting bodies during the postharvest period. Therefore, microwaves can be applied as a pretreatment method, providing valuable insights regarding postharvest mushrooms.