EFFECTS OF PACKAGING MATERIAL AND FORM ON FOOD STORAGE CHARACTERISTICS

Three kinds of plastic packaging material and three different packing types (ordinary packing,vacuum packing and nitrogen filling) were selected to analysis plastic material properties and packing form on the storage characteristics of snack food in the present study.The tested plastic packaging materials were nylon film,polyester film and polypropylene film obtained from the related food plants.It is found that the polyester film had the strongest tensile strength and tensile strain which was not easy to deformation through film impact test.The moisture permeability of three kinds of packaging materials was analyzed,and the value of nylon film,polypropylene film and polyester film were 13.4,12.36 and 11.60 g·m^-2·d^-1,respectively.The results showed that the change of water content of snack food was closely related to the moisture permeability of the packing material.The negative correlation existed between the moisture permeability and evaporation loss rat.Different packaging materials could be selected according to the water vapor transmittance for products with different shelf life.The results of packing form experiments showed that the change of moisture content,peroxide value and fat acid value of the snack food in nitrogen-filling packing type were better than those of the other two packing forms.Nitrogen-filling packaging had less moisture loss,and the original quality of food could be better maintained.With the prolongation of storage time,the peroxide value and acid value of food under the three packaging forms all showed an increase trend,but the rising rate of food with nitrogen-filling packaging was slower,which was beneficial for the maintenance of food quality.