Mulberry Leaf Protein Extraction and EDTA-2Na Affect Its Extraction Process

In order to explore the optimum extracting conditions with non-denatured principle for leaf proteinfrom mulberry, use Na2HPO4-citric acid buffer to extract mulberry leaf protein and study the rate of proteindegradation. Through 4 factors and 3 levels orthogonal experiments, 4 factors including material-liquid ratio,extracting time, extracting temperature and pH value were optimized. Protein yield and protein extraction ratewere 2 indicators to find the most optimum processing parameters. The results showed that the most optimumconditions were as follows: pH 7.6, material-liquid ratio 1:10, extracting time 25 min, extracting temperature15℃. As soon as the author beated fresh leaves the cell walls must be destroyed, the protein in the cell mightdecompose by the action of the autolysis enzyme, which would lead to a lower leaf protein extraction rate.Under the optimum conditions the author added a certain amount of EDTA-2Na as a protease inhibitor beforebeating so as to enhance the rate of protein extraction. It was found this optimum concentration by observingthe protein degradation curve with different concentrations of EDTA- 2Na. Ultimate it showed that duringextraction, 5 mmol/L of EDTA-2Na could minimizes protein degradation.