Novel surface activation technique using energy curable material for the production of bioactive packaging

Aparna Kothapalli, Purdue University

Abstract

Bioactive packaging is a class of active packaging in which bioactive components such as enzymes are immobilized to the food contact area of the polymer matrix. Although the concept of bioactive packaging was first explored in the 1950's, commercial examples of such packaging systems are very scarce. The reason for this can be mainly attributed to the lack of a rapid and effective immobilization technique that can be carried out in-line with the polymer roll stock production. The overall goal of this project was to examine if UV and e-beam polymerization techniques commonly used in the polymer coating industry could be adapted for the rapid production of bioactive packaging. The objectives of the study were to use glucose oxidase/catalase and lactase as model systems and to examine the effect of UV and e-beam polymerization on the activity and kinetic profile of the enzymes. The enzymes (glucose oxidase and lactase) were immobilized on low density polyethylene, a common food contact package layer. The activity and kinetic profile of the immobilized enzymes were compared with those of the free (soluble) enzymes. Ultraviolet (UV) polymerization typically requires the use of a photoinitiator for the production of free radicals. The migration of photoinitiator molecules into the food substance poses regulatory issues. Thus as an alternative, e-beam polymerization, which does not require the use of a photoinitiator, was also examined. Based on the guidelines from Food and Drug Administration (FDA), the extraction experiments were conducted on the UV and e-beam cured polymers and analyzed using gas chromatography/mass spectrometry (GC/MS) for extraction of residual monomer, polymer breakdown products and photoinitiators. UV polymerization effectively immobilized the enzymes with high retained activity, for both enzyme systems tested. The results from the GC/MS analysis of FDA extractables, indicate that e-beam polymerization could be safe and effective for binding of bioactivity without the need for photointiators. The results of this study indicate that UV and e-beam polymerization can be used as rapid and effective techniques for the immobilization of enzymes on packaging materials and ultimately for the production of bioactive packaging.

Degree

Ph.D.

Advisors

Morgan, Purdue University.

Subject Area

Food Science|Polymer chemistry

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