Utilization of Plant Protein Hydrolysates in an Instant Porridge Mix with Improved Protein Digestibility and Palatability

Aging affects protein digestibility due to the altered GI function, resulting in malabsorption and physiological changes. This study aims to formulate a plant-based instant porridge mix with increased protein digestibility and an enriched protein content. Protein hydrolysates were prepared using groundnut and pumpkin seed isolates by sequential enzymatic hydrolysis with alcalase and thermolysin. This dual-enzyme approach facilitated the release of smaller peptides, which is beneficial for muscle health and metabolism. Incorporating hydrolysates in a semolina and green gram-based porridge mix significantly increased the protein content from 8 to 21% and the in vitro protein digestibility (IVPD) from 71% to 85% along with a reduction in starch digestibility. There was an overall improvement in the amino acid profile, with the PDCAAS value reaching 0.84 from 0.59 in the control. The bitterness of hydrolysates, often a barrier to consumer acceptance, was effectively overcome by the addition of spices and citric acid, validated through sensory and E-tongue analysis. FTIR spectra showed the interaction between protein hydrolysates and starch molecules due to hydrogen bonding. Changes in the physicochemical and pasting behavior were also observed. The final formulation showed desirable sensory characteristics and consumer acceptability, highlighting its potential as a functional food for the aging population.