Endpoint Temperatures in Precooling Delay Lignification and Improve Storage Quality of Postharvest Bamboo Shoots

Field heat and lignin accumulation significantly impact bamboo shoot quality. In this study, crushed-ice precooling was utilized for field heat removal, with different endpoint temperatures (0°C, 5°C, 10°C) evaluated against untreated controls during storage at 4°C. Results demonstrated that the treatment with a 5°C endpoint temperature (T2) optimally preserved quality with minimal lignification, outperforming the 0°C (T1), 10°C (T3), and the control (CK) treatments. The T2 treatment reduced respiratory rate by suppressing the accumulation of malondialdehyde (MDA), H₂O₂, and O₂ ^-, and by inhibiting the activities of phenylalanine ammonia-lyase (PAL), peroxidase (POD), and polyphenol oxidase (PPO), while enhancing the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT). This collectively slowed the lignification process. Additionally, the T2 treatment better maintained moisture content, soluble proteins, soluble sugars, flavonoids, and phenolics, thereby effectively delaying quality deterioration.