Abstract: To investigate the effects of 1-methylcyclopropene (1-MCP) and ethylene absorbent applied alone and in combination on the postharvest softening of hawthorn fruits, ‘Qiuguo’ hawthorn fruits were subjected to three treatments: 1-MCP, ethylene absorbent, and their combined treatment. During storage, physiological and metabolic indices, nutritional quality indices, cell wall component contents, and metabolism-related enzyme activities were determined. Changes in cell wall microstructure were observed, and correlation analysis was performed. The results showed that compared with the single treatments, the combined treatment was more effective in inhibiting the rate of ethylene release and respiratory intensity, delaying the increase in relative electrical conductivity, and maintaining fruit firmness. It also slowed down the losses of total soluble solids, titratable acid, ascorbic acid, and total phenols. Additionally, it significantly retarded the conversion of protopectin to water-soluble pectin and the degradation of cellulose, and inhibited the activities of pectin methylesterase, polygalacturonase and cellulase. The combined treatment effectively delayed the postharvest softening of hawthorn fruits by inhibiting the activities of key enzymes involved in cell wall metabolism and retarding the degradation of cell wall components, thereby maintaining cell wall structural integrity. This study provides a theoretical basis for optimizing preservation technologies for hawthorn fruits.

Key words: hawthorn fruits; 1-methylcyclopropene; ethylene absorbent; fruit softening; cell wall metabolism