Partially hydrolyzed lentil and pea protein isolates: Techno-functional properties and bioactivity

This study investigated the impact of enzymatic hydrolysis on the techno-functional and bioactive properties of lentil (LPI) and pea (PPI) protein isolates. Tryptic hydrolysis of LPI and PPI with a target degree of hydrolysis (DH ~1%) reduced the amount of larger molecular weight (Mw) subunits in the lentil (LPH) and pea (PPH) protein hydrolysates. Upon hydrolysis, total solid solubility (TSS) and colloidal stability of lentil and pea proteins were improved at their isoelectric point, however, TSS of LPH was decreased at neutral pH, likely due to protein aggregation from hydrolysis-induced unfolding and heat inactivation of the enzyme. Both LPH and PPH expressed slightly reduced emulsifying activity compared to their parental protein isolates; this phenomenon may be attributed to the reduced surface hydrophobicity and the reduced diffusion-driven interfacial adsorption found in the hydrolysates. Lastly, hydrolyzed protein ingredients showed increased bioactivity, including higher total phenolic contents. • Lentil and pea protein isolates were partially hydrolyzed with a target DH ~1%. • High Mw protein subunits such as 11S, 8S, and 7S were degraded to smaller peptides. • The partial proteolysis enhanced the solubility of protein ingredients at pH 4.5. • Foaming capacity and stability of lentil protein ingredients were improved. • Proteolysis increased total phenolic contents in both pulse protein dispersions.