Alcalase and bromelain hydrolysis affected physicochemical and functional properties and biological activities of legume proteins

Abstract

Abstract In this study, protein isolates extracted from pigeon pea (PPI), lentil (LPI) and chickpea (CPI) were hydrolyzed by Alcalase and bromelain. The soluble components of the hydrolysates were characterized and compared with the non-hydrolyzed protein isolates and the whole protein hydrolysates. Alcalase-treated protein isolates showed higher degree of hydrolysis as evidenced by high levels of smaller peptide. The surface hydrophobicity of all hydrolysates is lower than protein isolates. Water absorption capacity and oil binding capacity of three proteins were enhanced by bromelain treatment. Antioxidant activities, as measured by scavenging the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (NO) radicals, of PPI and LPI are better than CPI. The soluble components of the hydrolysates obtained from bromelain treatment inhibited DPPH from 20.5 % to 32.3 %. Alcalase and bromelian exhibited similar effects on the NO radicals scavenging capacity of legume protein isolates. On the other hand, Alcalase hydrolysates exhibited higher oxygen radical absorbance capacity than bromelain hydrolysates. At 2 mg/mL, soluble components of bromelain hydrolysates inhibited the production of pro-inflammatory molecule NO in lipopolysaccharide-induced macrophages from 50.3 % to 59.2 %. Our results showed the potential of enzymatic hydrolysis for the production of functional ingredients with antioxidant and anti-inflammatory properties from legume proteins.