Chitosan-Mediated Metabolic Regulation Alleviates Cold Damage and Enhances Quality in Dwarf Bananas

Dwarf bananas are an important tropical fruit crop. They are particularly susceptible to cold stress, which often leads to quality deterioration. Although previous studies have examined the effects of cold stress on dwarf bananas, research on effective regulatory strategies and underlying mechanisms remains limited. This study investigates the mechanistic regulatory effects of chitosan (CTS) on cold stress in postharvest dwarf bananas, revealing that CTS mitigates cold-induced injury and improves fruit quality. Using an integrated approach of metabolomics, lipidomics, and enzyme activity assays, this study explored the potential mechanisms by which CTS alleviates chilling injury. Lipidomic results showed that CTS enhances cold tolerance by regulating the metabolism of glycerides, glycerophospholipids, linoleic acid, and linolenic acid. Metabolomics data further indicated that CTS increases the levels of amino acids, carbohydrates, and key substrates and intermediates of the tricarboxylic acid (TCA) cycle in cold-stressed dwarf bananas. Collectively, these effects enhance respiration, energy homeostasis, and antioxidant capacity, enabling dwarf bananas to better tolerate low-temperature stress.