Effect Of Top Air Body In Milk Powder Packaging On Its Stability

Milk powder packaging has developed from ordinary packaging,vacuum packaging,nitrogen-filled packaging to mixed gas packaging.During the shelf life of milk powder,milk powder caking,as well as vitamins and other sensitive nutrients will be attenuated,and the composition of milk powder headspace has a certain impact on its stability.The purpose of this study is to find the appropriate proportion of mixed filling gas in milk powder packaging,and compare it with single gas packaging in this proportion to explore its stability,extend the shelf life of milk powder without affecting the stability of milk powder,and ensure the quality and safety of milk powder.The canned milk powder with different aeration ratios was used as the test object.The pressure in the tank,fat and vitalins,non-enzymatic browning,water activity,agglomeration and total number of colonies were used as stability indexes.The variation of the stability of the milk powder in gas packaging and mixed gas packaging during the shelf life.It was revealed that the chemical powder inactive in the milk powder package（N₂,CO₂）affected the changes of various indexes during the preservation period.The case of the proportional control of the aeration and the influence of thepressure inside the tank on the expansion tank were studied.The suitable ratio of thelixed gas was determined to be CO₂/N₂＝6:4.The attenuation of DHA/ARA in the shelf life of the lixed gas packaged milk powder and the single gas packaged milkpowder was studied.And the fat decay caused by the change of peroxide value and anisidine value;the attenuation of representative vitamin A,vitamin D,vitamin C and vitamin B12:in the shelf life of mixed gas packaged milk powder and single gas packaged milk powder was studied;Changed in absorbance,HMF content,water activity,flow index,non-enzymatic browning and agglomeration during milk powder storage and consumption.In the harsh environment of high temperature or humidity、the air-filled packaging had a certain protective effect,inhibiting browning and agglomeration,wherein the stability of the mixed gas packaged milk power was relatively best。and the stability of the air packed milk powder was the worst.The stability of all factors ranks as followed:Mixed gas packaged milk powder>nitrogen packaged milk powder>carbon dioxide packaged milk powder>air packaged milk powder.The mixing ratio of CO₂/N₂=6:4.had good stability and could be implemented in factory production and could be considered in the rest parts of the country.