Effect Of Cooking On Oxalate In Vegetables

Objective: To understand people eat how much oxalate(soluble oxalate,insoluble oxalate,total oxalate)when eat food which are full of high oxalate, we set up an experiment to study the effect of different cooking duration and cooking conditions on oxalate in spinach and find out the effect of the bean curd when cooking spinach with it.. After that we choose some vegetables and cook them to find out the difference among them after the same cooking.Methods: Spinach obtained from local market and cook with three Chinese traditional methods (frying, cooking with water, stewing) under different duration and conditions; cook spinach with bean curd under different duration and conditions; choose bamboo shoot,cane shoot,green soybeans,spinach and cook them with the same Chinese traditional methods (frying, cooking with water, stewing) to make clear the difference. Deal with the sample carefully and determine the oxalate of them by potassium permanganate.Results: 1. About soluble oxalate and total oxalate: every group after stewing was significantly different from others, soluble oxalate decreased by 64.7％and43％; every group which cooked with water with different duration was significantly different from others, the soluble oxalate decreased more with the duration increasing, but there was no significant difference in groups with different amount of water; There was no significant difference in every group fried with different duration or different weight of edible oil. About insoluble oxalate all groups had no significant difference.2.After adding bean curd, the decreases of soluble oxalate in spinach are 41.2％,52.7％,60.5％and 60.7％; in different duration there was no difference between groups with bean curd or no, except 3min; All groups with different amount of bean curd had no significant difference and there was no significant difference in every group in soup without influencing factor. 3. Cooking different food with the same cooking, we can fred that there was so big difference among these foods. The bamboo shoot,cane shoot,green soybeans got the decreases of 60.8％,16.8％and 23.4％after stewing, 66.7％,37.3％,24.0％after cooking with water, 8.4％,0,46.1％after frying.Conclusions: 1. The effect of decreasing oxalate in spinach with three methods is cooking with water＞stewing＞frying.2. It is important to decrease the oxalate with water and cooking for a long time.3. The insoluble oxalate is hard to decrease and it is all eaten when people eat spinach.4. We can see different effect when cooking vegetables with some cooking methods.