SBIR-STTR Award

Modified a. nosphere packaging (MAP) is increasingly used to extend the storage and shelf life of fresh fruits and vegetables. Typical atmosphere compositions range from 2 to 7% ¡2 and I to 10% CO2. Atmosphere requirements vary with each commodity and must be maintained within a narrow window to prevent damage to the food. Packages have been developed using semipermeable plastic films to exchange respiration gases with the outside environment to generate and maintain the desired conditions. Respiration rates of many commodities increase strongly with temperature while gas permeabilities of existing plastic films increase only slightly with temperature. Consequently, even a small increase in temperature can result in damaging CO2 concentrations and/or anaerobic conditions inside the package. A new type of food packaging film is proposed based on IntelimerTm temperature sensitive polymers. The oxygen and carbon dioxide permeability of these films can be tailored to increases with temperature in a manner closely matching the respiration rate of fresh fruits and vegetables. Selected films will be developed for MAP applications, the oxygen and carbon dioxide permeation behavior will be measured over the temperature range of O¡C to 25¡C and a temperature abuse compensating package designed.Applications:Phase I studies will demonstrate the development of Intelimer-based temperature responsive semipermeable polymeric films having oxygen and carbon dioxide permeation properties that match the respiration properties of commercially important fruits and vegetables. The suitability of these films for use in preventing temperature abuse induced damage will be determined by modeling and constructing and evaluating test packages. Use of Intelimer films in Modified Atmosphere Packaging is expected to expand the development and use of modified atmosphere packages. By increasing storage and shelf life and reducing food loss these films will benefit the grower, the distributor and the consumer. Significant cost savings are anticipated and food safety is improved by avoiding anaerobic condition

Modified atmosphere packaging (MAP) can extend the storage and shelf life of fresh fruits and vegetables. Typical atmosphere compositions range from 2 to 7% ¿29 and 1 to 10% CO2. Atmosphere requirements vary by commodity and must be maintained in a narrow window to prevent damage to the food. Semipermeable plastic films may be used to exchange respiration gases with the outside environment to generate and maintain the desired conditions. Respiration rates of most commodities increase strongly with temperature while gas permeabilities of existing films increase only slightly with temperature. Consequently even a small increase in temperature can result in damaging CO2 concentrations and/or anaerobic conditions inside the package. A new type of food packaging film based on Intelimer (r) temperature sensitive polymers was demonstrated by Landec Corporation during Phase I. Studies showed that the oxygen and carbon dioxide permeability of these films can be tailored to increases with temperature in a manner closely matching the respiration rate of fresh fruits and vegetables. In Phase II we will design and characterize improved polymers and films structures suitable for specific cornmercial produce applications.

Anticipated Results:
Phase II research is directed toward demonstrating polymer compositions and film structures which will be commercially viable in value added packaging. Studies of produce quality and shelf life under conditions of temperature fluctuation are designed to show the benefit of abuse compensating films. Use of Intelimer (r) films in Modified Atmosphere Packaging is expected to expand the scope and commercial use of modified atmosphere packages. By increasing storage and shelf life and reducing food loss, these films will benefit the grower, the distributor and the consumer. Automatic prevention of anaerobic package conditions will provide improved food safety.