Effects of Torrefied Sawdust–Vermiculite Mixtures as Ethylene Scavengers on Shelf-Life Extension of Fruit Quality

Abstract

Torrefied sawdust has gained attention as a carbon-rich material with enhanced porosity and adsorption properties, making it a promising candidate for ethylene scavenging to extend fruit shelf life. In this study, torrefied oak sawdust was mixed with vermiculite to prepare ethylene scavenger mixtures, and their adsorption performance and effects on fruit quality were systematically evaluated. Laboratory-scale measurements showed that increasing the proportion of torrefied sawdust significantly enhanced ethylene adsorption. Response surface methodology (Box–Behnken design) identified optimal preparation conditions (66% torrefied sawdust, 2 mm particle size, and 342 h exposure) yielding an adsorption efficiency of approximately 84%. Compared with pure vermiculite, the optimized mixture provided substantially higher ethylene removal capacity and contributed to more than a two-fold extension of apple shelf life during storage. These findings highlight the potential of torrefied sawdust–based mixtures as effective, low-cost ethylene scavengers for postharvest fruit preservation and provide valuable design parameters for future material optimization.