Hot water treatment after harvest preserves nutritional quality of spinach during storage

The concentration of antioxidants in fresh produce is important in terms of human nutrition. The main antioxidants, found in relatively high concentrations in leafy vegetables, are ascorbic acid (AsA), carotenoids and flavonoids. There is an increasing interest in finding ways to improve the nutritional quality of vegetables by increasing or maintaining antioxidant content during storage. This study has investigated the effect of postharvest high temperature treatments on nutritional quality changes in spinach during subsequent storage. Ascorbic acid was determined by HPLC during storage. The hot water (40°C) pre-treatment reduced AsA loss during storage of spinach. However, the treatment was only effective in the case of spinach leaves subsequently stored at 0°C, while in spinach leaves stored at 6°C this effect was lost. In conclusion, hot water (40°C) treatment can potentially be used for nutritional quality preservation in spinach leaves. Physiological processes induced by hot water treatment require further investigation.