Rearch On Sevral Key Technologies Of Modified Atmosphere Packaging For Perishable Fruits And Vegetables

Modified atmosphere packaging (MAP) is an storage method which uses respiration of fruits and vegetables and the permeability of packaging films, to establish and maintain the dynamic equilibrium of gas concentrations in the packaging system. MAP is an important technology extending the shelf life of fresh fruits and vegetables, and it has been the focus of subjects at home and abroad.In this paper, the effect of the logistics condition on modified atmosphere packaging was considered for Agaricus bisporus and Strawberry, and the theoretical and experimental research on the logistics modified atmosphere packaging technology was carried out.The research work mainly included as follow:(1) The respiration rate of Agaricus bisporus and Strawberry was measured by the close system method at temperatures 5,15, 20 and 25℃. Based on the Michaelis-Menten equation, combined with Arrhenrius, the temperature parameter--activation energy has been abtained. Therefore the respiration model was been established. Lastly the model was tested for its validity at 10℃, the result showed a good agreement between experimental values and model values.(2) Fixed frequency vibration tests were carried out to study the effect on the respiration rates for Agaricus bisporus and Strawberry. It showed that both the amplitude and vibration acceleration have the joint effects on the respiration rates,and the approximation of critical vibration acceleration was generated.(3) The MAP threshold experiment design was completed for Agaricus bisporus and Strawberry. During the storage period, sensory and physical chemistry indexes was evaluated and measured for three packaging types. Comprehensive fuzzy evaluation model was established, and the evaluation scores have been abtained through the matrix calculation.Then limited oxygen fermentation thresholds were genereted: 2-3% for Mushrooms, 4-5% for Strawberry.(4) Applying the gas exchange model and the respiration rate model, a preliminary design method of logistics modified atmosphere packaging was proposed, including the packaging film selection and the optimization method of gas concentration.