Optimization of Extraction Process and Agglutination Activity of Moringa oleifera Leaf Protein by Response Surface Methodology

Moringa leaves are rich in protein, but less soluble. In this study, the protein from fresh Moringa leaves was extracted by salting out method and its activity was studied. Using fresh Moringa leaves as raw material, the effects of extraction time, ammonium sulfate saturation, and solid-liquid ratio on the protein yield were analyzed. On the basis of single-factor experiments, the response surface methodology was used to optimize the extraction of Moringa oleifera protein by salting out method optimum process conditions. The results showed that the effects on protein yield were in order of extraction time > ammonium sulfate saturation > solid-liquid ratio, and the optimal process conditions were determined as extraction time 7 h, ammonium sulfate saturation 71%, and solid-liquid ratio 1:9 g/mL, under this condition, the yield of Moringa leaf protein was 13.49 mg/g, which was basically consistent with the predicted result of 13.76 mg/g. The agglutination titer of Moringa oleifera protein was 2⁸, and D(+) anhydrous glucose was a specific inhibitory sugar of Moringa lectin, which could better inhibit the agglutination reaction of rabbit erythrocytes and Moringa oleifera protein.