Umami and saltiness enhancements of textured pea proteins by combining protease- and glutaminase-catalyzed reactions

Plant-based meat analogs (PBMAs) have attracted attention owing to their various advantages, however, their taste limits their application, requiring improvement of the umami and saltiness levels while meeting clean-label requirements. Enzymatic treatments for food processing are effective strategies for developing clean-label food products because enzymes are not considered food additives. In this study, we aimed to enhance the umami and saltiness intensity of PBMA patties by combining protease- and glutaminase-catalyzed reactions. For the production of extrudates to construct PBMA patties, enzymatically hydrolyzed pea proteins (eHPP) were produced via enzyme catalysis combinations, followed by the preparation of eHPP-mixed textured pea protein (eTPP) from eHPP and starch. Sensory evaluation revealed that the umami, kokumi, and saltiness levels of the eTPP-based patties containing 0.5% NaCl were significantly higher than those of the control patties containing 0.5% NaCl. Notably, the eTPP-based patties exhibited a 20% salt reduction. By screening for saltiness-enhancing amino acids and peptides released from eTPP-based patties in artificial saliva, the combination of Glu, Arg, Lys, and the separated peptide 3 was determined important in enhancing the saltiness intensity of NaCl. Moreover, it was revealed that the saltiness-enhancing peptide 3 may be a Maillard-induced peptide, based on the Lys residues in Glu-Gly-Lys-Gly and 5-hydroxymethylfurfural condensed from Glucose in starch during the extrusion process. Our findings suggest that the combination of proteases and glutaminases could be an attractive approach to enhance the umami and saltiness levels of PBMA products while meeting clean-label requirements.