Abstract: Changes in physiological indices, bioactive contents and microstructure of ‘Changkou’ hawthorn fruits treated with 1-methylcyclopropene (1-MCP) or ethylene absorbent (EA) were determined during controlled freezing-point storage. The results showed that compared to other treatments, 1.0 μL/L 1-MCP combined with controlled freezing-point storage at ?1.0 ℃ efficiently inhibited ethylene production and respiratory rate, delayed the ethylene production peak and respiratory peaks, lowered the conversion rate of protopectin into soluble pectin, maintained pulp hardness better, mitigated the degradation of flavonoids in pulp and the increase of anthocyanin content in pericarp, efficiently restricted the loss of soluble solids and titratable acid, declined mass loss percentage and browning rate, and increased marketable fruit percentage. Controlled freezing-point storage was an effective means of preserving fruit pericarp and pulp tissue structure. Overall, 1.0 μL/L 1-MCP treatment combined with controlled freezing-point storage at ?1.0 ℃ could be an appropriate method to maintain the quality of hawthorn fruits.

Key words: hawthorn, controlled freezing-point storage, quality preservation, 1-methylcyclopropene, ethylene absorbent