Optimization of the extraction and precipitation process of a leaf protein concentrate from Moringa oleifera Lam.

This study aimed to determine the best extraction and precipitation conditions of Moringa oleifera Lam. leaf protein. The influence of pH (10, 11, 12) and the concentration of NaCl (0, 0.25, 0.5) for the protein extraction process were studied through a Completely Randomized Design (CRD) with factorial arrange 32. The combination of pH 11 and 12 with 0 M NaCl had the best yield (P<0.05). The treatment of pH 11 without NaCl followed a precipitation stage for its purification, and the effect of different levels of pH (4, 4.5, 5) and temperature (40, 60, 80 °C) were evaluated using a CRD with factorial arrange 22 and 6 central points. The temperature did not affect the yield of the process in a significant way and the amount of precipitate was maximized at pH 4 and 4.5. From 100 g of the dry leaf, 7.26±0.19 g of protein was isolated with a recovery of 26.93±0.22 g 100 g-1 from the total protein. Due to their astringency and bitterness, consuming large amounts of Moringa oleifera Lam leaves is not a solution; therefore, obtaining a leaf protein concentrate could be useful for diverse applications in nutritional supplements, and as raw material for functional products development.