Hot water pre-treatment alleviates chilling injury in sweet potato: Synergistic regulatory effects on antioxidant and energy metabolism

Abstract

This study investigated the alleviating effects of hot water (HW) treatment on chilling injury (CI) in sweet potato tuberous roots stored at 5 °C. Results showed that HW48 ℃-10 min effectively mitigated CI and browning degree during cold storage. Specially, HW48 ℃-10 min maintained cellular structural integrity, as evidenced by lower relative conductivity, poor malondialdehyde accumulation, lower lipoxygenase activity, and a more intact microstructure. Furthermore, the treatment enhanced the activities of superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase, while strengthening antioxidant capacity and reducing membrane damage. Additionally, higher energy charge levels, as well as activities of cytochrome oxidase, succinate dehydrogenase, Ca^2 +-ATPase, and H⁺-ATPase, were observed in samples treated with HW48 ℃-10 min, which were positively related to membrane damage repair during cold storage. Overall, HW48 ℃-10 min would be a promising approach for preserving sweet potato tuberous roots under cold storage.