Tea Tree Oil Delays Kiwifruit Ripening Through Regulating Energy Metabolism

Abstract

Kiwifruit is easy to ripen and soften after harvest. Tea tree oil (TTO) has important application value in postharvest fruit preservation. However, the effect of TTO on kiwifruit fruit ripening, quality maintenance and energy metabolism, has not been studied. In this research, we found that TTO could delay ‘Xuxiang’ kiwifruit ripening, and keep good quality even after 18 days of storage. In three different concentrations of TTO treatments, 2.0 mL L⁻¹ TTO has the best preservation effect on kiwifruit. TTO slowed down the softening and degreening, reduced the respiration intensity and delayed the peak of respiration. Moreover, TTO also delayed the decrease of total sugar, titratable acid (TA) and vitamin C (Vc). The fruit treated with TTO kept higher levels of ATP, ADP and energy charge (EC), and higher activities of succinate dehydrogenase (SDH), cytochrome C oxidase (CCO) and ATPase. Correlation analysis results showed that kiwifruit ripening was closely related to nutritional quality and energy metabolism. To summarize, TTO could delay kiwifruit ripening and keep fruit quality by maintaining higher energy level and activities of energy metabolism-related enzymes during the late storage. This study will provide theoretical and technical support for kiwifruit preservation.