Study of Extractable Substances and Microbial Penetration of Polymeric Packaging Materials to Develop Flexible Plastic Containers for Radiation Sterilized Foods

摘要

Flexible packaging laminates were developed and evaluated for use with prepackaged irradiation-sterilized ham, bacon and chicken. Laminate structures comprised poly (ethylene terephthalate) as the outside ply, aluminum foil as the middle ply, and heat sealable inside ply, namely film of polyolefin, polyamide or polyester. These laminates were evaluated for food compatibility, low-temperature resistance, and resistance to microbial and insect penetration. The flexible laminate with the polyamide as the food-contacting film was found satisfactory for use with prepackaged ham, chicken and bacon in various test environments over a one year storage. A flexing apparatus, developed to induce bacterial penetration through defects in flexible packages, was found capable of detecting leaks not visible to the naked eye. The three types of flexible laminates showed no negligible weight loss and no package rupture in shipping vibration tests performed as low as -180C. Exposure of the flexible laminates to three types of boring insects over a three month period caused no complete penetration of the packages under study. (Author)