Effects of Edible Coatings and 1-MCP Treatments on Retention of Peel Green Color during Postharvest Storage in Sudachi Fruit

Abstract

Maintenance of green peel is desirable during storage and marketing of sudachi (Citrus sudachi Hort. ex Shirai) fruit. This study investigated the potential of edible coatings and 1-methylcyclopropene (1-MCP) treatment in extending the postharvest life during storage at 10, 15, and 20°C. Edible coatings were applied on freshly harvested green sudachi fruit either as a layer by layer (LBL), which involved alternate deposition of chitosan and alginate, or as an ion complex (IC) coating, which involved one-time deposition of a chitosan and alginate mixture. Storage at 10°C maintained the green peel color for up to 15 d with no significant differences among the treatments. At 15 and 20°C, the edible coatings significantly lowered ethylene production and respiration rates, and noticeably maintained green peel color for up to 19 d when applied as tri-layer IC, and 15 d when applied as tri-layer LBL. In addition, tri-layer IC coatings during storage at 15°C appeared to be more effective as they further extended the green peel stage to 21 d compared with 7 and 11 d for mono-and bilayer coatings, respectively. By contrast, 1-MCP treatment failed to inhibit peel yellowing, but instead stimulated fruit respiration and ethylene production. From these results, it is evident that edible coatings may provide a promising postharvest method to extend the postharvest life and preserve the quality of sudachi fruit.