Functionality and structure of protein isolate from decolorized moringa leaf

The leaves of Moringa oleifera are rich in protein and could serve as an alternative protein source for food fortification, enhancing various products. However, their use in foods is limited due to their green coloration, which negatively impacts consumer acceptability. This project's aim is to examine the impact of decolorization on the functionality and structure of Moringa oleifera leaf powder (MOLP) protein isolate. Decolorization significantly (p ≤ 0.05) changed the proximate composition of MOLP. In general, decolorized MOLP had a higher moisture, ash, and protein content compared to the un-decolorized MOLP (UDMP). Conversely, the fat (4.33%) and carbohydrate (53.75%) contents were higher in the UDMP than in the decolorized MOLP (DMP), which had 0.66% fat and 52.09% carbohydrate. Decolorization significantly influenced the water absorption capacity of the isolate but did not affect its oil absorption capacity. The decolorized protein isolate showed twice the water absorption capacity of the un-decolorized sample, presumably due to differences in the amount of charged and polar amino acids on the surface of the molecule. Scanning electron images revealed that the decolorized protein isolate particles were smaller than those of the un-decolorized isolate. The foaming and emulsion capacities of the isolates were dependent on pH. Glutamic acid and aspartic acid were the major amino acids in both isolates, but decolorization appeared to reduce the total amino acid content in the protein isolate. This study indicates the potential of Moringa protein as a food-fortifying ingredient, enhancing the nutritional and physicochemical properties of various food products. Future studies should focus on optimizing decolorization techniques, investigating long-term stability, examining other functional properties, conducting comprehensive nutritional and toxicological analyses, assessing consumer acceptability, and developing scalable industrial processes.