Hyperoxic storage increases the content of the active components in the post-harvest Ganoderma lucidum fruiting body

Abstract

This study investigates the effect of hyperoxic storage on the antioxidant properties and bioactive substance metabolism of post-harvest Ganoderma lucidum fruiting bodies. During storage, the fruiting bodies experienced weight loss, which positively correlated with oxygen content. Oxygen treatment facilitated the increase of antioxidant enzyme activity and the decrease of membrane peroxidation. The enzyme activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) were increased by 58 %, 149 %, and 64 %, respectively; malondialdehyde (MDA) content was reduced by 39.91 % compared to the control group when the fruiting bodies were stored in 80% oxygen for 5 d. Meanwhile, the contents of Ganoderma polysaccharides and ganoderic acid increased with time, attaining maximum values of 121 g kg−1 and 8.23 g kg−1 on 4th d and 5th d, respectively, which were 36 % and 32 % higher than the control group. When the fruiting bodies were stored in 40 % and 80 % oxygen, the expression of key enzyme genes involved in the metabolism of Ganoderma polysaccharides and ganoderic acid, such as phosphoglucose metatase (PGM), uridinediphosphate glucose pyrophosphorylase (UGP), β-1,3-glucan synthase (GLS), hydroxymethylglutaryl-CoA reductase (HMGR), squalene synthase (SQS), lanosterol synthase (LS) and squalene epoxidase (SE), was found to be upregulated.