塑料包装袋透气性对保鲜蔬菜颜色的影响

塑料包装具有一定的气体阻隔性,使包装内环境气体组成因蔬菜呼吸作用的进行而达到低氧、高二氧化碳状态,抑制了呼吸作用的进行,减缓蔬菜衰老变质,从而达到保鲜目的;但二氧化碳浓度过高、氧气浓度过低又会造成无氧呼吸并积累有毒物质,因此在保鲜包装中应使用具有一定透气性的包装材料,以保证包装袋内外可发生一定程度的气体交换。本文测试了四种塑料包装材料的气体透过率,利用自制计算机视觉系统跟踪测试了经过其包装后蔬菜在6d内的颜色变化情况,初步分析了塑料包装袋透气性对蔬菜颜色的影响,从护色角度得出了聚酯/聚乙烯较适宜作为蔬菜包装材料的结论。

Effect of the Gas Permeability of Plastic Packing Bag on the Fresh- preservation Vegetable Color

Plastic packaging has certain character of gas separation. It can reach the state of low oxygen and high carbon dioxide in packing bag owing to vegetable respiration, on this state the process of respiration can be restrained, the vegetable demotion slow down, accordingly fresh-preservation purpose is reached. But too high the density of carbon dioxide and too low density of oxygen is in packing bag, anoxic respiration and accumulate poisonous material of vegetable can be caused, therefore in fresh-preservation packaging, the packing material of certain gas permeability will be used in order to ensure the necessary gas exchange. In this paper the gas permeability of 4 kinds of plastic packing materials has been tested using self-made computer visual system. And the color change of vegetable is tested using the bags in 6 days, the effect of the permeability of plastic packing bag on vegetable color has been analyzed preliminarily. The conclusion that multiplex material making from polyester and polyethylene is more suitable to pack the vegetable.