果蔬微孔膜内湿度调节包装设计及试验验证

Design of equilibrium-modified atmosphere and humidity packaging for postharvest fruits and vegetables and validation test

在保持果蔬包装内气氛的条件下,通过优化并控制包装内的相对湿度,减少了果蔬袋内凝水和失水,试验结果对果蔬采后品质影响显著。通过对果蔬冷藏期间的气体传递、果蔬蒸腾以及薄膜透湿过程进行分析建模,确定包装贮存气氛环境条件,近一步利用所建模型设计微孔参数和薄膜面积,从而使果蔬在贮藏时保持适宜的气氛和相对湿度条件。以双孢菇为试验对象,通过测定双孢菇呼吸速率,设计合适的微孔数量、直径以及薄膜面积;通过贮藏试验对比多种薄膜面积包装内气体组分、失重率、亮度和相对湿度,对模型进行试验验证。结果表明,在5℃、100 g的双孢菇根据模型计算得出的微孔参数(n=4,d=50μm)、薄膜面积(442~553 cm^(2))条件下,与其他组相比能够保持较好的气氛范围[O_(2)为(5±2)%,CO_(2)为(17±4)%]和相对湿度(93%~100%),显著抑制双孢菇的多酚氧化酶活性,在贮藏10 d后的亮度值为83.48±0.61,失重率为(3.86±0.44)%,保鲜期可达12 d,试验数据与模型预测值具有较高的吻合度。

This study aimed to optimize and control the relative humidity conditions inside the package while maintaining the atmos-phere inside the fruit and vegetable package,thus reducing the impact of condensation and water loss inside the bag on the post-harvest quality of fruits and vegetables.By analyzing and modelling the gas transfer,fruit and vegetable transpiration,and film moisture permeabili-ty processes during fruit and vegetable refrigeration,the environmental conditions of the package storage atmosphere were determined,and the microporous parameters and film area were designed using the proposed model to maintain a suitable atmosphere and relative humidity conditions for fruit and vegetables during storage.The model was validated by measuring the respiration rate of Agaricus bisporus and desig-ning the appropriate number and diameter of micropores and film area,and comparing the gas fraction,weight loss rate,brightness,and relative humidity inside the package under various film area packages through storage tests.Results showed that 100 g of Agaricus bisporus could maintain a better atmosphere range[(5±2)%for O_(2) and(17±4)%for CO_(2))]and relative humidity(93%-100%)compared with other groups under the microporous parameters(n=4,d=50μm)and film area(442-553 cm^(2))calculated according to the model in 5℃environment,and after 10 d of storage.The brightness value was 83.48±0.61 and the weight loss rate was(3.86±0.44)%,which maintained the storage quality better and the freshness period was up to 12 d.The experimental data had a high agreement with the model prediction.