Postharvest application of salicylic acid enhanced antioxidant enzyme activity and maintained quality of peach cv. ‘Flordaking’ fruit during storage

Peach fruit has become very popular among stone fruits in Pakistan with increasing production. The main area of peach production in Pakistan is Swat, in the northern part of the country. Significant fruit losses occur during harvest temporary storing, and transport to market. Objective of this study was to determine the effectiveness of salicylic acid (SA) at different concentrations (0, 0.5, 1.0, 1.5 or 2.0 mmol L−1) on postharvest life of peach fruit (cv. ‘Flordaking’). Fruits were treated with SA immediately after harvest and stored at 0 °C for 5 weeks. Generally, all of the SA concentrations gave a higher activity of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) during five weeks of storage. The 2.0 mmol SA concentrations showed the highest activity for enzymatic antioxidants. The fruit browning enzyme polyphenol oxidase (PPO) activity decreased in SA treated fruits. SA treated fruits exhibited higher radical scavenging activity (RSA) than control fruits. The SA 2.0 mmol concentration resulted in increased fruit weight, firmness, and decreased juice pH. The higher concentration of SA (2.0 mmol) proved to be the most effective in keeping peach fruit quality intact along with maintained skin color and delayed fruit surface decay during storage. Conclusively amongst all treatments SA 2.0 mmol application exhibited maximum antioxidants enzymatic activities, minimum weight loss, stored firmness and decreased pH during storage period.

► Peach fruit treated with salicylic acid and stored for five weeks in cold store which exhibited reduced PPO activity, weight loss, fruit softening, L*, C* and h° values and contained juice pH as compared with control.
► During storage, treated fruit with salicylic acid showed higher SOD, CAT, POD and free radical scavenging activities, increased L* values, soluble solids content and overall acceptability.