Trans-2-hexenal-loaded gelatin/dialdehyde starch/nanocellulose cushioning aerogel: synergistic postharvest preservation of Chinese bayberry with 1-MCP.

Abstract

Chinese bayberry is a highly fragile and perishable fruit that requires protective and functional packaging to maintain its postharvest quality. In this study, a novel bio-based aerogel was developed using a gelatin/dialdehyde starch matrix reinforced with cellulose nanofibrils (CNF) via Schiff-base crosslinking and freeze-drying. The as-prepared aerogel exhibited superior compressibility, elasticity, and biodegradability. This aerogel was further functionalized by loading trans-2-hexenal (E2H) and combined with 1-methylcyclopropene (1-MCP) treatment, thereby constructing a postharvest preservation system for Chinese bayberry with the triple functionality of ethylene inhibition, antifungal activity, and cushioning performance. The optimal aerogel formulation (30% CNF content) demonstrated robust mechanical performance and sustained E2H release behavior, which followed first-order kinetics. In vitro and in vivo assays confirmed its significant inhibitory effect against Penicillium citrinum, the primary postharvest pathogen of bayberry. Storage experiments at 4 °C revealed that the synergistic effect of E2H-loaded aerogel pads and 1-MCP treatment effectively reduced decay, preserved firmness and nutritional quality, and extended the shelf life of bayberries to 18 d, significantly surpassing the control group which lost commercial value after 8 d. Furthermore, the aerogel completely degraded in soil within two weeks, confirming its potential as an eco-friendly packaging material. This work, integrating both protective and active preservation functionalities, provides a sustainable and efficient packaging approach for fragile fruit.