The Study Of Effect Factors Of Lipid Oxidation In Milk Beverage And The Choice Of Flexible Packaging Material

A large number of unsaturated fatty acids are rich in milk beverages, which have high nutritional value. Nonetheless, unsaturated fatty acids are very prone to be oxidized, due to some factors such as temperature, light, and oxygen. The bad taste has been produced in the process. In addition, some oxidation products may be toxic. Therefore, the paper mainly researched the influence of its degree of oxidation due to temperature, light and the oxygen permeability rate of packaging materials, in accordance with the indicator, lipid oxidation degree, in walnut milk; base on the theory of food shelf life, the shelf life model of milk beverages is presented. And it conducted a comprehensive evaluation combined with the physical properties of typical packaging materials.On the basis of the research of domestic and foreign scholars on the mechanism of lipid oxidation and anti-lipid oxidation packaging and theoretical analysis on shelf life of dairy products,the research work mainly included as follow:1) According to the study of the mechanism of lipid oxidation,milk fat oxidation rate was determined through the storage of test under the conditions of different temperatures (23℃,30℃和37℃) and darkness. Through the application of relationship on temperature and food quality rate,the best shelf life formula of lipid oxidation was established under the influence of the temperature.2) Combined with the light oxidation mechanism of fat, through the storage test of the different light intensities and a given temperature, the paper tested the impact of light on lipid oxidation degree; and based on shelf-life equation of photo-oxidation, requirements were put forward on light transmittance of packaging materials.3) According to the storage test of simples in four different packaging materials and the mechanical property test of this four packaging materials, it obtained the influence of the oxygen transmission rate on lipid oxidation of walnut milk. The results showed that lipid oxidation rate of products increased with the increase of oxygen permeability rate, while the oxygen permeability rate of packaging materials was larger; the oxygen permeability rate was not apparent on the role of lipid oxidation while it's smaller. Therefore, aluminum plating film can substitute for polymer-aluminum packaging material in the requirement of a long shelf life.