Abstract: The effects of cinnamon oil (CO) and its inclusion complex with β-cyclodextrin (β-CD) on preserving the quality of fresh-cut watermelon were evaluated by examining their impacts on the changes of microbiological, physicochemical and sensory quality indicators. Untreated samples were used as controls. Results showed that mass loss rate, total bacterial count and titratable acid content of the fresh-cut watermelon showed an increasing trend during storage, while L* and a* values exhibited a downward trend. The content of soluble solids first increased and then decreased. In addition, the above indicators displayed slower changes during cold storage compared with storage at room temperature. Among all treatments, CO-β-CD inclusion complex (containing 0.040 8 g of CO per 100 g of watermelon) combined with 4 ℃ storage had the best preservative effect on fresh-cut watermelon by effectively inhibiting the increase of mass loss rate and titratable acid content, weakening browning degree, and maintaining higher soluble solid content. Moreover, the total number of microorganisms in watermelon subjected to this treatment was significantly lower than that in the control and other treatments (P < 0.05) and the sensory score was significantly higher compared with the control and CO treatment groups (P < 0.05), suggesting that this treatment could maintain the commerciality of fresh-cut watermelon. The stability of CO could be improved and its strong odor could also be masked after being embedded into β-CD. The inclusion complex could effectively maintain the quality and prolong the shelf life, and thus have a good prospect in the preservation of fresh-cut watermelon.

Key words: cinnamon oil, β-cyclodextrin, inclusion complex, fresh-cut watermelon, preservative effect