TEMPERATURE ABUSE COMPENSATING FILMS FOR MODIFIED ATMOSPHEREFOOD PACKAGING

MODIFIED ATMOSPHERE PACKAGING (MAP) IS INCREASINGLY USED TO EXTEND THE STORAGE AND SHELF LIFE OF FRESH FRUITS AND VEGETABLES. TYPICAL ATMOSPHERE COMPOSITIONS RANGE FROM 2 TO7% O2 AND 1 TO 10% CO2. ATMOSPHERE REQUIREMENTS VARY WITH EACH COMMODITY AND MUST BE MAINTAINED WITHIN A NARROW WINDOWTO PREVENT DAMAGE TO THE FOOD. PACKAGES HAVE BEEN DEVELOPEDUSING 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 INTELIMER(STABILIZER) TEMPERATURE SENSITIVE POLYMERS. THE OXYGEN AND CARBON DIOXIDE PERMEABILITY OF THESE FILMS CAN BETAILORED 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 0 DEGREES CENTIGRADE TO 25 DEGREES CENTIGRADE AND A TEMPERATURE ABUSE COMPENSATING PACKAGE DESIGNED.