Extraction of Plant Based Protein from Moringa oleifera Leaves using Alkaline Extraction and Isoelectric Precipitation Method

Abstract

This study aimed to investigate the effect of solid-to-solvent ratio on the yield and properties of protein concentrate extracted from dried M. oleifera leaves powder by alkaline extraction and isoelectric precipitation method. Extraction of protein concentrate was carried out by manipulating the solid-to-solvent ratio (1:10, 1:20 and 1:30) that affects protein yield of MOLPC. The characterization of both chemical and physical functional properties was performed for dried M. oleifera Leaf Powder (MLP) and M. Oleifera Leaf Protein Concentrate (MOLPC). Fat absorption capacity (FAC) and water absorption capacity (WAC) of MOLPC were characterized at the different solid-to-solvent ratio and functional properties of MOLPC such as protein solubility, foaming and emulsifying capacity were characterized at different pH (2.0 – 11.0). The proximate analysis for the MLP had shown the moisture content (4.86 ± 1.18 %); ash (9.53 ± 0.07 %); crude protein (17.86 ± 0.23 %); crude fibres (12.54 ± 0.01 %) and fats (0.50 ± 0.38 %). Based on the findings, MOLPC tends to have higher protein content (26.58 ± 1.86 to 35.15 ± 3.4 %) compared to MLP. The FAC and WAC increased as the solid-to-solvent ratio increased (3.21 – 3.82 g/g and 5.19 – 6.41 g/g). For the functional properties of MOLPC; the protein solubility, foaming and emulsifying properties were all found to be pH-dependent.