Nutraceutical protein isolate from pigeon pea (Cajanus cajan) milling waste by-product: functional aspects and digestibility.

The aim of the present study was to utilize the protein from pigeon pea milling waste by-product for the preparation of protein isolate (PPI). The PPI was exposed to pepsin hydrolysis to reveal functional aspects like increased antioxidant capacity along with gelling ability. Complexation study demonstrated the use of PPI as an encapsulating material for water insoluble bioactive compounds (curcumin). Fluorescence spectroscopy revealed the formation of a complex through hydrophobic interaction. Ex vivo digestibility of the major proteins of PPI resulted in many peptides after digestion with human gastrointestinal enzymes. The peptide sequences identified may have potential biological activities, as revealed by bioinformatic data analysis. The presence of bioactive peptides and essential amino acids in the ex vivo digest suggests the role of PPI as a nutraceutical protein. The study provides a new value addition to pigeon pea milling waste by-product, a novel nutraceutical protein that can be used in functional food formulations.