Analysis Of The Contents Of NO₃～-,NO₂～-,Vc And The Antioxidant Activities Of Vegetables In Gui Yang

Vegetables are the plant that are easily accumulate nitrate. When the nitrate is breathed in by people,it will restore to nitr- ite,and nitrite can turn to Tobacco-specific nitrosamines which can induce cancer in the digestive system.VitaminC can prevent the formation of Tobacco-specific nitrosamines,there fore it can prevent cancer. Fruits and vegetables can clear away NO2- and its clearance rate has some relationship with the their Antioxidant Activities.So,the factors that the contents of nitrate,nitrite and VitaminC in the vegetable, and the antioxidant activities have become a very important criterion in the evaluation of vegetables quality.This paper is to study the clearance rate of the contents of the nitrate,nitrite and VitaminC and the percentages of .O2-,.OH- and H2O2 scavenged by vegetables in Gui Yang city. And we use LSR to analyze the data.From the analysis,we get the following results: There are great differences in the contents of nitrate, nitrite in the fresh vegetables in Gui Yang city.Generally speaking,leaf vegetables most likely to accumulate nitrate;even within the same vegetable,such as leaf and stem has different contents of nitrate and nitrite,and the contents of nitrate,nitrite in the leaves is more than in the stem.The clearance rate of aqueous extraction of five kinds of vegetables to nitrite, O2-,.OH- and H2O2,the fruits vegetables have the highest rate(23.43%);and the next is the leaf vegetables, flower vegetables,stem vegetables;and the last one is the root vegetables.All this demonstrates that there are rich active materials substances to clean out .O2-,.OH-,H2O2 , in the aqueous extraction in the fruits vegetables;and it has the highest of the antioxidant activities. The clearance rate of the aqueous extraction in the leaves and stems vegetables is: leaves>stems.