APPLICATION OF OXALIC ACID TO PRESERVE THE OVERALL QUALITY OF ROCKET AND BABY SPINACH LEAVES DURING STORAGE

The effect of postharvest treatment with oxalic acid (OA) on the overall quality of two leafy vegetables, rocket and baby spinach, was investigated for the first time. The leaves of rocket and baby spinach were dipped in 1 mM OA solution for 1 min and then stored for 6 days at 8C. As control, the leaves of rocket and baby spinach were immersed in hypochlorite, as currently practiced by fresh-cut companies. OA treatment significantly delayed deterioration during storage, with clear benefits for overall quality. Specifically, OA reduced the visual quality loss and yellowing of the leaves, slowing down the respiration rate, ammonia production, chlorophyll degradation and electrolyte leakage. In addition, the antioxidant activity and total phenol content were preserved by OA treatment. Finally, OA reduced the mesophilic aerobic count, with a performance similar to that of hypochlorite washing. Thus, OA treatment might be a valid method for preserving the postharvest overall quality of rocket and baby spinach.