Evaluation of MAP engineering design parameters on quality of fresh-sliced mushrooms

Modified atmosphere packaging (MAP) relies on the interplay between product-respiration and package-film-permeability with the aim of maintaining initial quality and extending shelf-life of fresh produce. This work evaluates the effect of MAP engineering design parameters (amount of product, number of perforations and weight of CO₂ scavenger) on quality of sliced mushrooms. Sliced button mushrooms were packed in a tray, covered with cellophane film, and stored at 10 °C for 3 days. Headspace gas composition and chemical and physical quality parameters (weight loss, pH, firmness and colour) were measured throughout the storage period. All design parameters produced a significant effect (p < 0.05) on quality. Addition of CO ₂ scavenger in the package increased the deterioration of mushrooms. MAP optimisation design requires consideration of mushroom weight and number of film perforations. The optimal conditions found were 110 g of sliced mushrooms and 2 perforations (0.33 mm diameter) which led to an equilibrium gas composition of 3.6% O₂ and 11.5% CO₂, after 3 days of storage at 10 °C.