Postharvest application of boric acid on grapes to improve the shelf-life and maintain the quality

Boric acid (BA) is commercially acceptable and economically feasible material to enhance the shelf life of pears, oranges and other horticultural plants. Here, we investigated the effect of BA on the shelf life and post-harvest quality of table grapes (cv. ‘Kyoho’). The grapes were immersed in a BA solution with different concentrations [0 (as the control), 10, 30, 50 mM] for 10 min and stored at 25 ± 1 °C for 10 days. Compared to the control, the BA treatments maintained higher berry firmness by inhibiting the activity of polygalacturonase (PG) and cellulase. In addition, the BA-treated grapes maintained higher antioxidant enzyme activities, such as catalase (CAT) and superoxide dismutase (SOD), and lower metabolic toxic products, like the superoxide anion (O2-) production rate, malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) content than the control. The experimental results showed that the post-harvest application of BA effectively delays the senescence of grapes compared with the control, and the 10 mM BA treatment had the most obvious effect.