The effect of exogenous salicylic acid on antioxidant activity, bioactive compounds and antioxidant system in apricot fruit

To improve the postharvest nutritional and functional qualities of apricot fruit, the fruits were treated with salicylic acid (SA) by vacuum infiltration. The effects of SA treatment were investigated via analyzing of the quality attributes especially related to antioxidant activity, active oxygen metabolism and antioxidant system during the storage of apricot fruit at 2 °C for 25 days. Our results showed that significant higher hydrophilic total antioxidant activity (H-TAA) and content of phenolic acids, flavonoids were found in fruits treated with SA. SA treatment reduced the lipophilic total antioxidant activity in apricot fruit. During storage, application of SA significantly enhanced activity of phenylalanine ammonia-lyase (PAL) and content of hydrogen peroxide. Treated fruits showed significantly lower activity of catalase and ascorbate peroxidase but higher activity of superoxide dismutase and peroxidase than those in control fruits. Moreover, SA treatment retarded the ripening progress and quality loss. Thus, SA treatment might enhance the activity of PAL, H-TAA and content of phenolic acids via regulating the metabolism of hydrogen peroxide in apricot fruit.