抗氧化载体复合可食用膜的控释特性影响规律及机制研究

Active edible films with antioxidant activities have been widely studied recently. Researchers have always been concerned about how to achieve the controlled release antioxidant activities of edible films with limited antioxidant substances. The encapsulation of antioxidant substances within carriers provides a solution to this issue. Our previous results showed that the controlled release properties were obtained when antioxidant substances were encapsulated within chitosan carriers, and the release rate could be controlled by encapsulation efficiency. Therefore, the influences of chitosan carriers’ structure characteristics, such as particle morphology and structure compactness, on the release properties of antioxidant substances will be further studied. The relationship between release properties and their own structures of film-forming materials and/or microstructure changes in edible films caused by the addition of carriers will be systematically analyzed. Moreover, the controlled release mechanism based on structure characteristics of carriers and films will be investigated by tracking the migration and diffusion of antioxidant substances within edible films during storage. This study can provide theoretical basis for accurately controlling the release of antioxidant substances, and further provide technical guidance for preparing carrier composite edible films with high and sustaining activities.

抗氧化活性是目前可食用膜功能化领域的研究热点。其中，如何在抗氧化物质添加量有限的情况下，实现可食用膜的控释抗氧化是研究者们一直以来关注的问题。抗氧化物质的载体化为这一问题的解决提供了方向。前期的研究表明，壳聚糖载体可实现抗氧化物质的缓释，且释放速率可通过抗氧化物质的包封率来控制。基于此，本项目拟进一步研究壳聚糖载体的颗粒形态、结构紧密度等结构特性对抗氧化物质释放特性的影响规律；系统分析可食用膜基材自身结构特性及载体添加带来的微观结构的差异与抗氧化物质释放特性的相关性；并通过跟踪储存过程中抗氧化物质在可食用膜中的迁移扩散情况，以阐明载体结构特性和膜结构特性对抗氧化物质的控释机制。本研究为抗氧化物质的精准控释提供理论依据，为高效、持续功能化活性载体复合可食用膜的制备提供技术指导。

在包装材料中添加抗氧化物质是在不影响食品感官基础上，实现食品抗氧化的重要途径之一。包装膜中的抗氧化物质会逐渐扩散释放到最易发生酸败变质的食品表面，补充消耗或损失的那部分抗氧化物质，阻止食品因氧化导致的腐败变质。然而，当抗氧化物质释放速率过快或过慢时，均不能在食品表面维持抑制氧化酸败的最佳补充量。因此，实现抗氧化物质的可控持续释放是抗氧化包装持续高效抗氧化的关键。本项目采用了载体技术将抗氧化物质先包载后再添加到膜材料，通过载体与膜基材对抗氧化物质的共同作用达到抗氧化物质控制释放；其次，通过成膜条件、交联处理及后处理实现了膜基质性能的调控；最后，根据研究过程中发现的包装中活性物质的释放受食品品质影响的事实，从食品本身品质变化引起的周围环境变化来调控活性物质释放的体念出发，基于酸敏亚胺键对pH响应的敏感性设计了具有pH响应控释特性的肉桂醛-壳聚糖席夫碱包装，实现了肉桂醛释放的可控性，获得了释放特性与食品保鲜需求的同步，本研究结果将为设计具有持续、高效抗氧化保护作用活性功能膜奠定理论依据。