Effects Of Oxalic Acid Treatment On Peeled Chinese Water-Chestnut During Storage At Low Temprature

Yellowing and microbial infection are the main problems impact on the quality of peeled Chinese water-chestnut tubers. In this paper, the effects of 5 and 10 mM oxalic acid treatment on the sensory, nutritional quality, cell membrane integrity, disease resistance, contents of total phenols and flavonoids and the related enzyme activities in the fresh Chinese water-chestnut tubers were investigated. The main results were as follows:1. Oxalic acid treatment obviously delayed the change in color of peeled Chinese water-chestnut tubers, and 5 mM was better than 10 mM of oxalic acid treatment. Moreover, oxalic acid effectively maintained the sensory and nutritional quality of peeled Chinese water-chestnut tubers during storage due to alleviating the weight loss, maintaining higher soluble solid and ascorbic acid content.2. Oxalic acid treatment effectively inhibited the respiration intensity of peeled Chinese water-chestnut tubers, increased the activities of CAT and SOD in peeled Chinese water-chestnut tubers, and effectively not only reduced the contents of H2O2, O2 and MDA, but also decreased the membrane permeability, which contributed to decreasing the damage of cell membrane and lipid peroxidation in peeled Chinese water-chestnut tubers, and in turn benefited to the integrity of cell membrane.3. Oxalic acid treatment inhibited the acitivites of PAL and PPO, and delayed the increase in flavonoid and total phenol content, and reduced the yellow degree and decay incidence of peeled Chinese water-chestnut tubers. In addition, oxalic acid treatment increased the activity of GLU, which could improve the disease resistance in peeled Chinese water-chestnut tubers during storage at low temperature.