title: Release of 1-methylcyclopropene from heat-pressed polymer films.
abstract: Gaseous 1-methylcyclopropene (1-MCP) is an inhibitor of ethylene perception that is being used extensively for apples and ornamental products, and under intensive investigation for its potential benefits for other fruits and vegetables. 1-MCP is currently used in closed environments that maintain stable concentrations for several hours in order to be effective. However, food packaging materials that release 1-MCP at a predictable rate into the package headspace might be useful for application in inhibiting the deleterious effects of ethylene in the postharvest packaging and storage of some horticultural products. A 1-MCP/alpha-cyclodextrin (1-MCP-cd) complex was incorporated into several common packaging films by heat-pressing (dry-blend, lamination) and solution-casting methods. The release of 1-MCP from the films was quantified by gas chromatography with respect to time, loading of 1-MCP, temperature, relative humidity (RH), type of film, and film-forming method. Release of 1-MCP was rapid and high in films held at RH >/= 75%. The rate of release was slow during the 1st 12 h and then increased during the next 24 to 36 h. Higher temperatures resulted in higher and faster release. A loading of 8 mg of 1-MCP-cd per 140 mg of polymer was found to be optimal. Pressing 1-MCP-cd containing films above 100 degrees C reduced the amount of 1-MCP remaining in the film. Incorporation into LDPE resulted in a higher and faster release than from PS, PVC, and PP polymers. 1-MCP release from a film matrix appears to be within the acceptable range for produce packaging applications.
authors.affiliation: Dept. of Food Science, Cornell Univ., 116 Stocking Hall, Ithaca, NY 14853-7201, USA. jhh3@cornell.edu
authors.forename: J H
authors.initials: JH
authors.lastname: Hotchkiss
authors.forename: C B
authors.initials: CB
authors.lastname: Watkins
authors.forename: D G
authors.initials: DG
authors.lastname: Sanchez
mesh_terms: D002849:Chromatography, Gas; D003521:Cyclopropanes / Q000302:isolation & purification* / Q000494:pharmacology; D005030:Ethylenes / Q000037:antagonists & inhibitors* / Q000378:metabolism; D018857:Food Packaging / Q000295:instrumentation* / Q000379:methods*; D005519:Food Preservation / Q000379:methods*; D005638:Fruit; D006813:Humidity; D013696:Temperature; D013997:Time Factors; D014675:Vegetables
chemical_list: D003521:Cyclopropanes; D005030:Ethylenes; C036216:ethylene; C412563:1-methylcyclopropene