Structure and in vitro bioactive properties of O/W emulsions generated with fava bean protein hydrolysates

Abstract

The use of plant-derived proteins in the generation of food products is gaining popularity as an alternative to proteins of animal origin. This study described the emulsifying and bioactive properties of fava bean protein hydrolysates (FBH) generated at low and high degree of hydrolysis (DH), i.e., FBH₈ (low DH: 8.4 ± 0.3) and FBH₂₁₀ (high DH: 15.6 ± 0.7) when adjusted to three different pHs (3.0, 5.0 and 8.0). Overall, FBH₈, had more favourable emulsifying properties compared to the FBH_210. The emulsion generated with FBH₈ at pH 8.0 also had the highest antioxidant activity when measured by the oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP) assays with values of 1108.6 ± 3.8 and 1159.9 ± 20.5 μmol Trolox Eq·g^-1 emulsion, respectively. The antioxidant activity of the emulsions, in most cases, remained unchanged following in vitro simulated gastrointestinal digestion. Both the FBH₈ and FBH₂₁₀ emulsions following in vitro simulated gastrointestinal digestion were able to inhibit the activities of dipeptidyl peptidase-IV (DPP-IV) and angiotensin converting enzyme (ACE) with ∼45% and 65% inhibition, respectively. These results indicated that hydrolysates from fava bean may find use for the generation of bioactive emulsions.

Keywords: Bioactivity; Emulsion; Fava bean; Protein hydrolysates; Simulated gastrointestinal digestion.