The need for safe food products has motivated food scientists and industry to find novel technologies for antimicrobial delivery for improving food safety and quality. Controlled release packaging is a novel technology that uses the package to deliver antimicrobials in a controlled manner and sustain antimicrobial stress on the targeted microorganism over the required shelf life. This work studied the effect of controlled release of nisin to inhibit growth of Micrococcus luteus (a model microorganism) using a computerized syringe pump system to mimic the release of nisin from packaging films which was characterized by an initially fast rate and a slower rate as time progressed. The results show that controlled release of nisin was strikingly more effective than instantly added ("formulated") nisin. While instant addition experiments achieved microbial inhibition only at the beginning, controlled release experiments achieved complete microbial inhibition for a longer time, even when as little as 15% of the amount of nisin was used as compared to instant addition.

Smart blenders controllably form multi-component polymer melts into a wide variety of fine-scale structural arrangements that can be retained in extruded plastics. The machines operate on the principle of chaotic advection, a recent subfield of fluid mechanics, and have been used to produce cast film and blown film but can also be used to extrude sheet, rod, tubing, and other products. Because and structure of a composite material influences greatly additive diffusion, and matrix dissolution, this processing method provides a means for producing packaging film, medications, and medical implants with tailored release rates of active compounds. In this article, an ability to alter release rates of tocopherol, a natural antioxidant of importance to food packaging, is specifically investigated via on-line specification of a process parameter governing blend morphology in extruded cast films. Blends of lowdensity polyethylene and polypropylene, and also low-density polyethylene and high-density polyethylene were used.

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