Effect of NO Treatment on Postharvest Storage Quality of Golden Hook Bean

Abstract

Golden hook bean readily turns purple and is susceptible to senescence after harvest, affecting its storage quality. In order to clarify the effect of NO treatment on the postharvest quality of golden hook bean, the bean was soaked in 0.2 mmol/L sodium nitroprusside (SNP) solution as an exogenous NO donor for 10 min and stored at (8 ± 1) ℃. The purpling rate, rust spot rate, appearance quality, color, total soluble solid (TSS) content, mass loss rate, hardness, antioxidant contents and antioxidant enzyme activity were determined during storage. Compared with the control group (immersion in deionized water), SNP treatment could effectively delay the occurrence of purpling and rust spot, reduce mass loss rate, maintain SSC, inhibit the decrease in anthocyanin content during the late storage stage, reduce the production of malondialdehyde (MDA), increase the contents of antioxidants such as total phenols, flavonoids and carotenoids, significantly increase catalase (CAT) and ascorbate peroxidase (APX) activity overall (P < 0.05 and P < 0.01), and inhibit the activities of polyphenol oxidase (PPO) and peroxidase (POD) (P < 0.05 and P < 0.01). Therefore, SNP treatment can delay purpling and senescence of golden hook bean during storage by regulating antioxidant enzyme activities and antioxidant contents, thereby maintaining its quality during storage and prolonging its storage period.

Keywords

• nitric oxide; golden hook bean; storage quality