Chlorine dioxide gas may modify properties of polymeric packaging materials.
[ClO.sub.2], in its gaseous form, has been used for vapor-phase decontamination, both in treating the produce before packaging and sanitizing products inside packages. Little is known about its effects on packaging system material properties and performance.
Research at Michigan State University and elsewhere indicates that changes in the performance of certain polymers, when they're used as packaging materials, could impact a product's shelf life. This research could provide the information needed for selecting materials when [ClO.sub.2] gas is being considered for inclusion in a packaging system as a bactericide that would improve the safety of fresh produce safety and prolong its shelf life.
In their research on the mass transfer of [ClO.sub.2], investigators determined the permeability, solubility and diffusion coefficients of [ClO.sub.2] for 10 types of polymeric packaging materials. Their approach involved using an isostatic technique. They used a continuous system that measured [ClO.sub.2] concentrations with an electrochemical sensor as a detector.
This effort showed that polyethylene terephthalate, polylactic acid, polypropylene, nylon, and multilayers of ethylene vinyl acetate and ethylene vinyl alcohol have high [ClO.sub.2] barriers. But polystyrene, linear low-density polyethylene, linear low-density polyethylene, high-density polyethylene and polyvinyl chloride demonstrated poor barrier characteristics to [ClO.sub.2].
The effects of gaseous [ClO.sub.2] on the physical and mechanical properties of polymeric packaging materials were also determined by exposing the selected materials to [ClO.sub.2] for one, seven and 14 days. Changes were observed, such as a significant decrease in the tensile strength and modulus of elasticity of the treated polyethylene samples. It also appears that changes occurred in the absorbance intensity of the infrared spectrum of polystyrene, polyethylene terephthalate, polylactic acid, and layers of ethylene vinyl acetate and ethylene vinyl alcohol, indicating that alterations occurred in the materials and their properties.
Further information. Rafael Auras, School of Packaging, Michigan State University, East Lansing, MI 48824; phone: 517-432-3254; fax: 517-353-8999; email: firstname.lastname@example.org.
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|Publication:||Emerging Food R&D Report|
|Date:||May 1, 2010|
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