包装膜透性对西兰花采后冷藏品质变化的影响

Effect of Packaging Film Permeability on the Quality of Postharvest Broccoli during Cold Storage

摘要:

本文研究了具有不同氧气（O2）和二氧化碳（CO2）透过率的包装膜对西兰花采后自发气调包装保鲜过程中包装袋内气体成分及西兰花贮藏品质变化的影响。采用预冷后的新鲜西兰花，经 4 种不同 O2和 CO2透过量的聚乙烯薄膜密封包装，包装袋尺寸为 30 cm×25 cm，调查了不同包装处理在 1±0.5 ℃下冷藏 60 d 包装袋内气体成分、组织电导率、色差、感官指标、Vc 和叶绿素指标的变化情况。结果表明，在本试验条件下，不同 O2和 CO2透过率的包装膜对包装袋内气体成分、色差 L*值和西兰花贮藏品质及货架期具有显著影响（p<0.05）。其中，O2和 CO2透过率分别为 16398.3 cm3/m2·24 h·0.1 MPa 和 68644.9 cm3/m2·24 h·0.1 MPa 的包装膜从贮藏第 1 d 开始即可维持包装袋内 O2（11.86~15.78 kPa/500 g）和 CO2（2.61~4.25 kPa/500 g）水平达到相对稳定状态，直至贮藏期结束袋内西兰花仍保持较好的新鲜度和总体感官品质。

Abstract:

The effects of packaging films with different oxygen and carbon dioxide transmission rates on the package headspace gas composition during modified atmosphere packaging (MAP) for the preservation of postharvest broccoli, and the changes in the storage quality of broccoli were studied. After precooling, fresh broccoli was packaged and sealed in 30 cm×25 cm polyethylene bags with four different oxygen and carbon dioxide transmission rates and stored at 1±0.5 ℃ for 60 d. Changes in package headspace gas composition, tissue electrolyte leakage, color difference, sensory attributes, vitamin C (Vc) content, and chlorophyll content were investigated. The results indicated that packaging films with different oxygen and carbon dioxide transmission rates significantly (p<0.05) affected package headspace gas composition, L* value, product storage quality, and shelf life under the conditions of this experiment. Among them, stable oxygen (11.86~15.78 kPa/500 g) and carbon dioxide (2.61~4.25 kPa/500 g) levels could be maintained in the packages with oxygen and carbon dioxide transmission rates of 16398.3 cm3/m2·24 h·0.1 MPa and 68644.9 cm3/m2·24 h·0.1 MPa from day 1, and the freshness and high overall quality scores of the products stored in these packages were maintained until the end of the storage period.