The Development Of A Film For MAP Storage Of White Hypsizygus Marmoreus

In order to select an optimal package film for the improvement of the shelf-lifequality of White Hypsizygus marmoreus, firstly, the characteristics of polyphenoloxidase （PPO） in White Hypsizygus marmoreus were studied by spectrophotometerusing catechol as the substrate. Then, the effects of different package films and UV-Cirradiation duration on some quality parameters of postharvest White HypsizygusMarmoreus at25℃±0.5℃were systematically studied. At last, the influences ofmodified atmosphere packaging combined with UV-C on several quality indexes ofWhite Hypsizygus marmoreus were investigated.The results were as follows:（1） The absorptive wavelength of enzymatic reactive product was420nm, and thereaction should be kept at least3min, while the optimal conditions for PPO shouldbe35℃and pH6.5, and the optimal substrate concentration was0.10mol/L. The12.75226kinetic equation of PPO wasV=[S]+17.3489, and the Km was1.59mol/L. ThePPO activity of stipe was much higher than other parts.（2） White Hypsizygus marmoreus is a climacteric vegetable. After the pretreatment ofUV-C irradiation for10min, the0.06mm PE film could significantly reduce therespiration rate and the activity of PPO, while restrain the growth of microorganism,at the same time, maintain the sensory index, hardness, total soluble sugar contentand weight.（3） The shelf-life quality of postharvest White Hypsizygus marmoreus during passiveMAP can be improved, e.g., the respiration rate and the activity of PPO could bedepressed, the better sensory index, rigidity, and higher total soluble sugar contentcan be maintained, when the UV-C irradiation duration was chosen as20min.（4） The white Hypsizygus marmoreus was sensitive to CO₂, the higher content of CO₂would aggravate the browning degree. When the initial O₂and CO₂ratio waschosen as0.4%O₂+13.0%CO₂+86.6%N2, the sensory index and rigidity could bewell maintained, and the respiration rate and the activity of PPO could besignificantly depressed, the gas composition of low O₂and high CO₂could beachieved, the losses of soluble total sugar could be reduced, and the shelf-life couldbe prolonged to more than7d, which means an acceptable MAP storage result.（5） The irradiation of UV-C combined with modified atmosphere（0.4%O₂+13%CO₂+86.6%N2） could significantly improve the storage quality, reduce the respiration, and slow down the loss of weight and total soluble sugarcontent of White Hypsizygus marmoreus..The results of this study could be taken as reference for the packaging technologyof White Hypsizygus marmoreus.