Evaluation of ethylene scavengers for potential application in fresh produce packaging
Fresh fruit and vegetables are sensitive products with a short shelf-life. Often these are packaged to maintain their quality for a longer time. Active substances can be added in packaging to provide additional benefits such as moisture absorption, antimicrobial effect or removal of foul odours. Among such active substances, some materials scavenge or remove ethylene. Ethylene is a colorless gas, often referred to as “ripening hormone,” produced by fruit and vegetables. Accumulation of ethylene in packages causes the undesireable fast ripening in fruit and vegetables. Commercial sachets containing scavengers are put in fruit and vegetable packaging to remove ethylene. This research is part of a “FreshInPac” project funded by CORNET that aims to develop bio-based multifunctional packages with ethylene absorbing and antimicrobial effects for extending shelf-life of produce. The objective of this study was to comparatively analyze various materials developed in-house as well as commercial scavengers for ethylene removal under similar conditions (temperature 20°C; humidity ~50%; and initial ethylene concentration 10 ppm in a 1-L glass jar). The materials investigated were categorized by their ethylene removing principle: 1) adsorbers (bentonite, sepiolite, halloysite, zeolite, diatomite): these can physically adsorb ethylene, thus, removing it from the environment; 2) adsorber-oxidizer (potassium permanganate (KMnO4) based products, commercial as well as KMnO4 deposited on zeolite in the lab): these chemically react with ethylene, thereby, converting it to other products and these materials are themselves used up in the process irreversibly; 3) catalyzers (titanium dioxide, magnesium oxide, and diatomite with palladium): these are similar to oxidizers except these remain unused at the end of the reaction. Natural clays and zeolite did not show any appreciable ethylene absorption. However, a pre-heat treatment of the materials removed attached moisture from the particles resulting in increased ethylene absorption capacity. KMnO4 based materials were the fastest and best at removing ethylene. Titanium dioxide-palladium absorbed ethylene slowly. These results will be helpful in improving ethylene scavenging materials to extend the life of packaged fruits and vegetables.
Namrata Pathak won the ISHS Young Minds Award for the best poster presentation at the XIII International Controlled and Modified Atmosphere Research Conference (CAMA2021), which was held virtually in Belgium in August 2021..
Namrata Pathak, Leibniz-Institut für Agrartechnik und Bioökonomie e.V. (ATB), Max-Eyth-Allee 100, 14469 Potsdam, Germany, e-mail: firstname.lastname@example.org
The article is available in Chronica Horticulturae