A Review of Ethylene Permeability of Films

Ethylene plays a major role in regulating fruit ripening and fresh produce senescence during the postharvest period. Accumulated ethylene inside a fresh produce package has the potential to stimulate physiological activity and consequently accelerate deterioration, limiting storage life and leading to product losses. Current scientific effort focuses on the minimization of ethylene effects through ethylene removal or suppression of ethylene response. Other researchers are focussing on the development of sensors for measuring ethylene exposure within supply chain systems in order to be able to use this information to indicate produce quality and predict remaining shelf life. Full and optimal utilization of either ethylene removal or sensing technologies requires knowledge of the rates in which ethylene can flow to or from the package that the product is contained in. This study discusses the need for ethylene permeability data for polymer films and reviews the data available. Ethylene permeability of commercial films was found to range from 57 to 2.7x10(-16)mol.m/m(2).s.Pa at ambient temperatures, with activation energies being in the range of 37 000-48 000 J/mol. Amongst novel films, some containing zeolites could be 10 times more permeable, while permeability of wheat gluten films was highly influenced by relative humidity. However, generally, to date, it would seem that there is a scarcity of information on the transmission of ethylene through commonly used materials, especially at industrially relevant conditions of low temperature and high relative humidity, making prediction of ethylene conditions within a commercial package difficult. Collection of ethylene transmission data for the wide range of available films at industrially relevant conditions is required in order to maximize the utilization of newly developed ethylene removal or sensing technologies and subsequently contribute to the reduction in fresh produce losses within the supply chain. Copyright (c) 2015 John Wiley & Sons, Ltd.