Study On The Preparation Of Decreasing The Nitrate Content Of Spinach

The nitrate was harmful to human which was confirmed by many researches, we analysed the physiological reason of nitrates accumulated based on understanding the variety of the nitrates accumulated ,tried to invent a safe and effective preparation and provided convenience for reducing the nitrate of spinach. The effects of spraying eighty different proportion of three components on nitrate contents of spinach were studied in order to select the optimum proportion based on pot experiment , then verified the results.There were three steps in this experiment, preliminary selection、final determination and verification test. Researching the effects of different treatment on spinach by measuring nitrate content、nitrate reductase(NR) activity and root activity。At last , A discs experiment was conducted to study the effects of potassium on nitrate content of spinach, The nitrate content of spinach were measured under different potassium and sodium ,and the activity of nitrate reductase,vitamin C, soluble sugar,soluble protein,chlorophyll content were measured under the suitable condition .The results are as following:1.Preliminary selection: the five final results were selected by measuring the output and the nitrate contents of eighty treatments. they were 49、50、68、78、80.ComponentⅠand componentⅠwere the main reagent ,they played main role in decreasing the nitrate contents,the componentⅢwas auxiliary reagent.2 Decreasing and final determination :through measuring nitrate contents and nitrate reductase(NR)activity ,we learned that nitrate content in petiole was the highest but that in leaf was the lowest, the nitrate reductase(NR) activity in leaf and in petiole differ by more than two times and the leaf was the major organ of nitrate reduction. so the nitrate in leaf could be reduced quickly, The results above demonstrated that there was negative correlation between the nitrate content and nitrate reductase(NR) activity as some people said .The root activity and quality of spinach were increased. Furthermore, five treatments could decreasing the nitrate content of spinach, the final preparation was 50,that is to say, the concentration of componentⅠw as 2mg·L~-1、componentⅠwas 1mg·L~-1、componentⅢwas 1mg·L~-1.3 Verification test: the nitrate contents of different kinds of spinach were decreased by spaying the preparation, and the quality have been raised to different extent.4 The results of potassium showed that, Treatment with 0.2% potassium tartrate for 2 hours reduced the nitrate in leaf discs significantly( reduced 60%, compared to control), and the activity of nitrate reductase increased 9.3 times compared to the control, and the chlorophyll content could be improved without decreasing content of vitamin C, soluble sugar ,and soluble protein.