不同包装材料和包装形式对食品储藏特性的影响

EFFECTS OF PACKAGING MATERIAL AND FORM ON FOOD STORAGE CHARACTERISTICS

收集了3种常用于食品包装的塑料包装材料,分析材料性能并选取一种材料,通过3种不同包装形式(普通包装、真空包装及充氮包装),对休闲食品辣条的储藏特性进行测试。从市场上相关食品厂选取3种不同组成的材料(尼龙薄膜、聚酯薄膜和聚丙烯薄膜)为试验材料。通过薄膜冲击测试,发现聚酯薄膜的拉伸强度和拉伸应变最大且不易发生形变。对3种包装材料的水蒸气透过率进行分析,尼龙薄膜为13.4 g·m^(-2)·d^(-1)、聚酯薄膜为11.6 g·m^(-2)·d^(-1)、聚丙烯薄膜为12.36 g·m^(-2)·d^(-1)。试验结果表明:食品水分的变化和材料材质本身的水蒸气透过率有较大关系,材料的水蒸气透过率越高则水分流失较快,两者呈负相关。对不同保质期的产品可以根据水蒸气透过率选择不同的包装材质。使用聚酯薄膜材料包装进行不同包装形式的储藏试验,试验发现:充氮包装的休闲食品在储藏期间的水分、过氧化值与酸价均优于其他两种包装。充氮包装下水分流失较少,可较好地保持食品原有的品质。随着储藏时间的延长,3种包装形式下食品的过氧化值和酸价均呈现上升的趋势,但充氮包装的上升趋势较缓慢,有利于食品品质的保持。

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.