Extension of the shelf-life of fresh oyster mushrooms (Pleurotus ostreatus) by modified atmosphere packaging with chemical treatments

Abstract

The objective of this study was to improve the preservation of fresh oyster mushrooms by modified atmosphere packaging (MAP) and chemical treatments. The MAP effects and treatments on organoleptic quality, weight loss, cell permeability, texture changes and polyphenol oxidase (PPO) activity were studied. In addition, three packaging materials were used for MAP mushroom storage. Low-density polyethylene (LDPE) proved to be a more suitable material than polyvinyl chloride (PVC) and LDPE-PVC as MAP materials. On the other hand, for mushrooms storage, MAP in combination with chemical treatments (sorbitol 0.05 g/100 g, CaCl₂ 1.0 g/100 g and citric acid 3.0 g/100 g) showed inhibitory effects on weight loss and mushrooms cell permeability. Furthermore, the results of polyphenol oxidase (PPO) activity, texture and organoleptic analysis also showed that active MAP, composed of 1.5% O₂ and 20% CO₂ and combined with chemical treatments, was found to be beneficial in maintaining oyster mushrooms quality and shelf-life.

Key words: Modified atmosphere packaging (MAP), oyster mushroom, shelf-life, preservation, chemical treatments.