Effects of forchlorfenuron treatment on the shelf-life quality of ready-to-eat kiwifruit and its mechanism

Ready-to-eat kiwifruit refers to kiwifruit with a uniform texture, maturity and favorable taste that can be consumed immediately after purchase without the requirement for a natural ripening process. Although extensive research has been conducted on the application of forchlorfenuron (CPPU) in kiwifruit cultivation, studies on its impact on the "edible window" of ready-to-eat kiwifruit and relevant mechanisms remain limited. In this study, to investigate the impact of CPPU treatment on the edible shelf-life qualities of ready-to-eat kiwifruit, we conducted an in-depth analysis of multiple aspects, including fruit qualities, enzyme activities, cellular structure, and metabolites. The results indicated that CPPU treatment increased the fruits' volume and weight, but decreased the firmness. During storage, CPPU treatment increased the respiratory rate of kiwifruit, with a peak respiratory intensity of 46.14 mg·kg⁻¹·h⁻¹ and 34.36 mg·kg⁻¹·h⁻¹ for the samples treated with or without CPPU, respectively. This suggested that CPPU accelerated the conversion of starch to sugar and the ripening of kiwifruit. At room temperature, the edible window of ready-to-eat kiwifruit not exposed to CPPU was 7 days, while the samples treated with CPPU was 5 days. This was probably attributed to the reduction in antioxidant enzyme activities like catalase and superoxide dismutase, and the increase in ɑ-amylase activity and malondialdehyde content after treatment with CPPU. The present study supplies useful information for developing ready-to-eat kiwifruit, especially for CPPU-treated kiwifruit.