作为食品包装技术研发人员,所开发的包装材料结构是否满足所包装食品的货架期保护需求?在满足货架期前提下,成本最优化的选择是什么?我最近在网站上看到了一篇日本包装研发人员所写的货架期试验报告,非常有借鉴意义.直接复制过来,供大家参考,有时间,我也想总结一下平时工作中对货架期的试验心得.

Study on the Shelf-life of Japanese Pumpkin Cracker in the Different Types of Package

Suchinda Nimmannittaya

Department of Packaging Technology, Faculty of Agro-Industry,

Chiang Mai University.

After packing pumpkin snack in 4 types of packaging materials which are

CPP50.8u  (Cast Polypropylene-50.8 micron),

OPP20/PE 40(Laminated Oriented Polypropylene-20 micron and Polyethylene-40 micron)

OPP20/CPP20 (Laminated Oriented Polypropylene-20 micron and cast Polypropylene-20 micron) and

OPP20/VMCPP25 or OPP20/Metallized CPP25 (Laminated Oriented Polypropylene-20 micron and Metallized Cast Polypropylene-25 micron),

and storing it at 20, 30 and 40˚C. From the 3 different temperatures, it is found that the pumpkin snack which was stored at 20˚C has the highest changing percentages of moisture content and water activity. Moisture content of pumpkin in CPP and OPP/VMCPP is higher than 3.5 percent after storing at 40˚C for 8 weeks (snack should not have percent of moisture content over 3.5). TBA (Thiobarbituric Acid Number), which is related to rancidity of snack, is slightly changed during the stored time for 10 weeks, after that the TBA will get higher. The data shows that TBA of the snack at 40˚C is the highest one, comparing to the snacks is 3 different temperatures.

In the second experiment, after storing the snack in 4 types of packaging material, at 32-35˚C and 85-95 % of relative humidity for 10 weeks, the snack in CPP bag has the same quality as the snack in OPP/VMCPP. The data shows that after keeping the snack in both types of package for 9 weeks, it is found that Aw of snack in CPP bag is 0.39±0.007 and Aw of snack in OPP/VMCPP is 0.30±0.0000. Likewise, the percentages of moisture content of the snack are as following, 3.46±0.0636 in CPP bag and 3.33±0.0212 in OPP/VMCPP bag.

TBAs in all types of package are not significantly different. For the sensory test, after storing the snack for 9 weeks, the value of rancidity, crispiness and overall acceptability of the snack in CPP bag are 3.58±1.66, 4.79±2.10 and 3.96±1.59 respectively, meanwhile the value in OPP/VMCPP bag are 4.75±2.11, 5.96±1.90 and 5.04±1.98, which are not significantly different in statistical evaluation.

According to the experimental data, it indicates that the 50.8 micron CPP bag from Royal Project Food Processing at Chiang Mai University, which is currently used for pumpkin snack, has the same quality as OPP/VMCPP bag. Both bags can protect the quality of products inside for at least 9 weeks at 32-35˚C and 85-90% of relative humidity. While the price of CPP bag is 65-66 percent cheaper than the price of OPP/VMCPP bag in the same size and thickness.