Effects of modified atmosphere package (MAP) with a silicon gum film window and storage temperature on the quality and antioxidant system of stored Agrocybe chaxingu

Packages of Agrocybe chaxingu with or without silicon gum film windows were flushed with an initial modified atmosphere (MA) 100 mL/L O2, 100 mL/L CO2 and balance N2 and stored at 1 °C and 3 °C, respectively. The changes in gas headspace, sensory, content of malondialdehyde (MDA), generation of superoxide anion, the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) of mushroom were investigated. A. chaxingu stored in MAP without silicon gum film window at 1 °C had the poorest sensory quality because of chilling injury and physiological injury caused by a combination of storage temperature and poor atmosphere conditions (O2 under 9 mL/L and CO2 above 172 mL/L since Day 4). These injuries induced a relatively high content of MDA and generation of superoxide anion. The antioxidant enzyme system, including SOD, CAT and POD, was stimulated, to increase activities and scavenge the reactive oxygen species (ROS) to reduce injury during the initial storage period. However, these injuries also induced senescence of the stored mushroom, which resulted in decreased activities of antioxidant enzyme system. The activities of antioxidant enzyme system of A. chaxingu stored in MAP with silicon gum film window at 3 °C was the most favourable to delay the senescence process in the latter part of storage period, and the mushroom had the best quality to the end of storage.