光照对PET瓶装UHT乳营养物质的影响研究

Research of the light radiation effect on the nutrient amount in UHT milk

本文重点研究PE T瓶包装UHT奶在光照条件下营养物质的变化情况。添加10%以上光阻隔剂的PE T瓶或采用添加炭黑为中间层的多层PE T瓶,在1 0 00 l ux光照条件下,U H T奶的P H值、乳糖、脂肪、粘度、蛋白、钙含量等指标随光照时间延长而变化不大。维生素Va、Vb2、Vc随着光照时间增加均呈下降趋势。在1000lux及5000lux下,所选择的包装方案中UHT奶Va指标在整个光照过程中呈相近下降趋势;Vb2和Vc含量指标随光照强度增加,下降更为显著。光阻隔剂含量在13%及以上或多层瓶方案,对Vb2有较好的保护作用;多层瓶方案更有利于Vc的保护。

This paper focuses on the effect of light radiation on the nutrients of UHT milk packed with PET bottles. PET bottles with more than 10% light blocking agent included or multilayer PET bottles with the middle carbon layer, were used to pack UHT milk and ke pt some items well under the experiment light radiation(1000 lux)for 90 days, which were p H, lactose, fat, protein, viscosity index,calcium content and so on.But the amount of vitamin decreased very significantly, such as Va, Vb2, Vc. Compared 1000 lux with 5000 lux, the content of Va had decreased with almost similar slope.The content of Vb2 and Vc decreased more significantly under stronger light radiation. Vb2 in UHT milk could be protected well for PET bottles with more 13% light blocking agent or multilayer PET bottles. Multilayer bottle was helpful to protect the Vc content of UHT milk, relatively.