Studies On Respiration Rate And Quality Of Atmosphere Packaged Agaricus Bisporus

Modified atmosphere packaging(MAP) is a well-established technology that can inhibits the respiration rate and metabolic activity of perishable produce, which helps in extending the shelf-life and maintenance of the quality of perishable produce.In order to solve the problems in modified atmosphere packaging of Agaricus bisporus,three parts were studied in this paper.Firstly,The gas permeability coefficients of different material films at 2,4,8 and 20℃were calculated by Small Bags Method.The influences of temperature on the gas permeability coefficient and gas permeability coefficient ratio were analyzed.The results suggested that the gas permeability coefficients of films increased with temperature;as the temperature increased the gas permeability coefficient ratio of LDPE increased significantly,while the gas permeability coefficient ratio of PVC kept stable.The relationship between permeability coefficients and temperature was well described by Arrhenius equation,and it was linear relationship between nature logarithmic of gas permeability coefficient and the reciprocal of temperature.Secondly,The package headspace composition,in terms of oxygen and carbon dioxide concentrations,in modified atmosphere package of Agricus bisporus at 2℃,4℃,8℃and 20℃respectively were monitored within 15h.The respiration rate of Agricus bisporus under modified atmosphere packaging at any instant of time were calculated by a C program based on permeable system.The dependence of respiration rate on gas composition was well described by a Michaelis Menten type equation with uncompetitive CO₂ inhibition.The model constants were estimated by fitting the model to the experimental data by non-linear regression using Excel,and the veracity and practicability of the respiration rate model were validated.The relationship between maximum rate V_m and temperature was well described by Arrhenius equation.Thirdly,A L₉(3)⁴ orthogonal test was carried out to evaluate the storage quality of Agricus bisporus under active modified atmosphere packaging with different temperature,packaging material,O₂ and CO₂ volumetric concentrations. Weight loss,fructification firmness,degree of browning,the respiration rate, membrane permeability,soluble solid content,polyphenoloxidase(PPO) and peroxidase(POD) activity of Agricus bisporus were investigated on the 3^th d,5^th d, 7^th d,9^th d,11^th d after storage,respectively.The optimum composition of active modified atmosphere packaging for Agricus bisporus was that storage temperature 2℃,packaging material PVC2,15%O₂ volumetric concentration,10%CO₂ volumetric concentration.