Improved nutritional and functional properties of plant protein isolate blends through steam infusion: A study on chickpea, brown rice and defatted peanut protein blends

This study examined the impact of steam-infusion on defatted peanut (Pn), chickpea (Cp), and rice (R) protein isolates (PI) and their blends. Steam infusion significantly increased protein content (up to 83.13 % in PnPI, 75.25 % in CpPI, 76.13 % in RPI) and digestibility (98.92 % in peanut, 98.84 % in chickpea) and improved protein solubility. Steam-infused protein blends (SIPB) showed higher protein content (84.44 %), digestibility (89.61 %), improved EAA scores, and enhanced functional properties compared to non-steam infused protein blends (NSIPB). SEM revealed porous, serrated structures in SIPB, while FTIR analysis showed higher β-turn content corroborated with higher protein digestibility. Also found higher β-sheet content that enabled high emulsion protein stability as revealed by analysis of emulsion proteins by TEM and optical microscopy. Herschel-Bulkley modelling demonstrated improved rheological properties, including shear-thinning behaviour [flow index (α < 1)]. Due to enhanced protein digestibility properties, SIPB can serve as a novel plant protein ingredient in protein-food industry.