基于气阻-气导混溶的自平衡气调包装对采后蔬菜呼吸生理和食用品质的影响

Modified atmosphere storage of vegetables is key issue for agricultural products’ preservation. Equilibrium modified atmosphere packaging technology has the advantages of high efficiency, low cost, saving energy and convenience, and has broad prospects for development. Existing theoretical system lacks the explanation of the mechanism of gas molecules acting on modified atmosphere packaging matrix. It affects the development of modified atmosphere packaging. In the previous work, the concepts of gas conductor and gas barrier were put forward. Using homogeneous blending， equilibrium modified atmosphere packaging with certain gas permeability were developed, and the mechanism of gas permeability was preliminarily verified. The topic is aimed to establish a systematic hypothesis for air conductor-air barrier. On this basis, the subject intends to (1) propose and verify the air conductor-air barrier hypothesis, and regulate the permeability of materials by changing the miscibility ratio of components; (2) design equilibrium modified atmosphere and monitor the dynamic equilibrium and steady state of gas components in packaging; (3) explore the respiratory intensity of vegetables under gas conditions in packaging; (4) monitor The changes of vegetable texture characteristics, color, moisture content and important chemical substance content; (5) calculate the shelf life of vegetable with using a key quality factor of vegetable storage as key factor; (6) analyze the influence of packaging materials on the safety of vegetable consumption, establish a theoretical system for the relationship of the gas permeability of packaging materials, the gas environment in packaging, the respiratory physiology of vegetables after harvest and the quality of vegetable consumption. This work provides theoretical support for the development of equilibrium modified atmosphere technology, and plays an important role for keeping storage quality and edible safety of vegetable.

蔬菜的气调保鲜是农产品贮藏领域关键性课题。自平衡气调包装技术具有高效、廉价、节能、方便等优点，具有广阔发展前景。已有理论体系缺乏针对气体分子在气调包装材料上作用机制的根源性阐释，制约了气调包装的开发。前期工作提出气导质和气阻质概念，均相共混开发具有一定气透性的自平衡气调包装，初步验证气透性原理。课题拟建立系统的气导-气阻假说，通过改变材料组分的混溶比，调控材料气透性；设计气导-气阻自平衡气调包装，维持适宜的气体组分动态平衡稳态；探究蔬菜在包装内气体条件下的呼吸强度，监测蔬菜质构特征、色度、水分含量和重要化学物质含量等指标的变化；确定蔬菜贮藏的关键品质因子，计算蔬菜贮藏货架期；分析包装材料对蔬菜食用安全性的影响，建立包装材料的气透性、包装内气体环境、蔬菜采后呼吸生理及蔬菜食用品质间影响关系的理论体系。项目为自平衡气调包装技术的开发提供理论支持，对维持蔬菜贮藏品质和食用安全性意义重大。

蔬菜是重要的农业作物，也是人体健康不可或缺的食物原料。中国的蔬菜产品加工水平相对较低，储运过程中损耗极其严重。自平衡气调包装作为抑制果蔬呼吸作用，保证果蔬贮藏品质的先进技术，方便、节能、高效、具有广阔的应用前景。.项目致力于通过接枝改性手段开发气导质材料，通过气导质和气阻质的共混，设计自平衡气调包装，维持适宜于蔬菜贮藏的气体环境，抑制蔬菜呼吸生理，保持其贮藏品质。.项目基于气导质-气阻质原理开发了一些列针对性自平衡气调包装，极大抑制蔬菜贮藏过程中品质劣变，将其保质期延长1.5到3.4倍，主要包括：①适用于西兰花的PEEK-PVDF自平衡气调包装。包装对二氧化碳、氧气和氮气的渗透性分别为1.05~14.95 barrer，0.19~2.97 barrer和0.05~0.44 barrer，二氧化碳/氮气和氧气/氮气分离因子分别为19.80~28.91和3.50~5.48，包装内氧气和二氧化碳平衡浓度分别为0.4 %~5.2 %和4.7~11.5 %。在此条件下，西兰花的感官评分、色度、质构、微生物、pH、叶绿素、总酚、抗坏血酸等品质参数的变化都得到抑制，货架期由15天增至30天以上。②适用于辣椒的SPEEK-PES自平衡气调包装。包装对辣椒的感官、颜色、质地和化学性状的维持具有显著的效果，特别是由60 %SPEEK和40 %PES组分构成的气调包装，维持了含有5.18 %氧气和3.16 %的二氧化碳的包装内环境，使辣椒货架期延长2.3倍以上。③适用于卷心菜的SPES-PES自平衡气调包装。包装可以最大限度地保持卷心菜感官、颜色、质构、叶绿素、总酚、总黄酮、抗坏血酸和亚硝酸盐等品质指标。其中，含有75 % PES和25 % SPES的包装可以维持内环境含有6.0 %二氧化碳和2.9 %氧气，将卷心菜货架期延长3.1倍。④其他包装，包括适用于草莓保鲜的SPEEK-PU自平衡气调包装；适用于圣女果保鲜的SPES-PVDF自平衡气调包装；适用于花椰菜保鲜的结冷胶-木质素自平衡气调包装；适用于豆角保鲜的壳聚糖-聚乳酸自平衡气调包装等。这些包装极大地延长了产品货架期，从理论和实践上丰富了自平衡气调技术，有显著的科学意义和应用前景。