Application of humidity-regulating tray for packaging of mushrooms

• Mushrooms lose moisture even at 100% RH.
• Humidity-regulating tray maintained a stable RH of 93% in a mushroom package.
• Humidity-regulating tray absorbed 4.1 g of water vapour within 6 days.
• Mushroom quality was better in humidity-regulating tray than plastic tray.

Major postharvest challenge of mushroom includes high transpiration rate resulting in rapid weight loss and the risk of water vapour condensation inside the package, which results in accelerated deterioration in quality and decay. Thus, this study investigated the transpiration behaviour of mushroom under various combinations of storage temperature (4, 12 and 20 °C) and relative humidity (RH) (76, 86, 96 and 100%) and assessed the impact of salt embedded humidity-regulating tray on humidity and condensation behaviour in mushroom package at 7 °C and 85% RH. The impact of humidity-regulating and control-polypropylene (control-PP) trays on condensation and quality of mushroom was evaluated after 6 days. Despite the saturated RH condition, across all temperatures studied, mushrooms stored at 100% RH lost moisture at the rate of 0.03–0.22 mg kg−1 s−1. Humidity-regulating tray maintained a stable RH (93%) inside the package and it absorbed 4.1 g of water vapour within 6 days at 7 °C and 85% RH storage condition. Humidity-regulating tray better maintained the quality of mushrooms compared to control-PP tray, but it absorbed only 4.1 g of water vapour in 6 days which was not enough to prevent water condensation in the package headspace for mushrooms.