Development of new palladium-promoted ethylene scavenger

Abstract The control of ethylene in stored environments plays a key role in prolonging the postharvest life of many fresh produce types. However, there has been a paucity of research in recent years on developing novel and more effective ethylene scavenging materials. In this study a palladium (Pd)-promoted powdered material that has significant ethylene adsorption capacity (4162 μL g −1 material) at 20 °C and approximately 100% RH was identified and was shown to be far superior to KMnO 4 -based scavengers when used in low amounts and in conditions of high relative humidity (RH). Initial screening was carried out in a plug flow reactor with 200 μL L −1 ethylene, 10% (v/v) O 2 balanced with He at approximately 100% RH. Further work demonstrated that the Pd-promoted material at either 0.01 or 0.03 g L −1 effectively scavenged both exogenously administered (100 μL L −1 ) and/or endogenously produced ethylene by banana or avocado, respectively, to sub-μL L −1 concentrations within a 24 h period. Optimum ethylene adsorption capacity was calculated as approximately 10,000 μL g −1 . Accordingly, corresponding inhibition of ethylene-induced ripening was observed. When removed, Pd-material did not disrupt subsequent ripening. The results from this study demonstrate that Pd-promoted material has commercial potential.