Changes in epidermal waxy morphology and related properties of postharvest sweet cherry

[Objective] This study aimed to reveal the reasons of different varieties for sweet cherry's storability and provide theoretical support and technical guidance for edible coating in its postharvest preservation. [Methods] Four representative sweet cherry varieties （Red Light, Rainey, Red Agate, and Friendship） were selected as research objects. The surface morphology of different varieties of sweet cherry skin, the contact angle of skin to different solutions, the changes of surface morphology, contact angle and critical surface tension of Red Agate sweet cherry during storage were investigated. [Results] There were differences in the distribution and morphology of wax on the epidermal of the four varieties of sweet cherry, and the contact angle of the skin to the same solution was significantly different. The wax content of the Red Agate epidermis decreased during storage. Due to the hydrophobicity of sweet cherry skin, adding Tween-20 as a surfactant to the coating liquid can significantly improve its surface wettability. The contact angle of the Red Agate epidermis to deionized water decreased during storage, and the critical surface tension increased with the extension of storage time. [Conclusion] The storability of different varieties of sweet cherries may be correlated with their skin characteristics. Adding 0.1% Tween-20 to the coating solution can make the solution more evenly coated on the surface of the sweet cherry.