Research On Keeping Quality Mechanism Of Packaging In Milk Powder And Prediction Method Of Shelf-life

Milk powder is one of the main dairy products. It contains protein, fat, sugar, vitamin, etc. During storage, these nutrients are unstable and easily cause biochemical reactions such as fat oxidation, enzymatic browning and vitamin degradation. Therefore, This paper focused on the deterioration mechanism and the influences of temperature, light and oxygen concentration for infant formula. The interrelated equations and the prediction model based on key quality indicator were obtained in accordance of prediction model theory for food shelf-life.This paper focused on researching on deterioration mechanism in milk powder and prediction method of shelf-life based on accelerated experiments. Results were as follow:(1) According to the study of fat oxidation, enzymatic browning and vitamin degradation in milk powder, indicator and method were determined and theory and method of storage accelerated testing were established.(2) Combined with deterioration mechanism in milk powder, enzymatic browning and vitamin C degradation were studied through the storage test under different temperatures and darkness. Rate of enzymatic browning and dynamic model of vitamin C degradation were obtained. Meanwhile, Shelf-life prediction model were established.(3) For milk powder packed with packaging materials of different light transmittance, during storage test under constant temperature and humidity, related indicators in milk powder were studied and equation for Shelf-life was obtained based on light intensity.(4) According to the study of milk powder packed with different oxygen concentration, the result showed propanal,pentanal and hexanal in milk powder packed with air had higher growth rate than others packed with low oxygen concentration or deoxidizing agent .Meanwhile, vitamin C degradation rate was obviously faster than the other two groups. Deoxidizer packaging for milk powder inhibited deterioration obviously.