Debittering and antioxidant improvement of soy protein hydrolysates using curcumin as hydrophobic core

Background: Protein hydrolysates possess various bioactive functions (e.g. antioxidant), but their bitter taste is unacceptable to most consumers. In the present study, a novel approach for debittering was introduced, which involved the utilization of a hydrophobic compound, curcumin (Cur). Soy protein hydrolysates (SPH), prepared through alcalase hydrolysis, served as the research model for this investigation.

Results: It was found that bitter intensity of SPH was dominated by the hydrophobic amino acid residues, and the addition of Cur could remarkably reduce bitterness. The debittering mechanism is attributed to the direct binding of Cur to the exposed hydrophobic amino acid residues of SPH via hydrophobic interaction, thereby shielding the hydrophobic bitter groups and hindering their interaction with the bitter taste receptors. Moreover, this debittering strategy leads to the generation of stable nanoparticles with a Cur-core/SPH-shell architecture, which can significantly improve the antioxidant capacity of SPH compared to those using biomacromolecules for encapsulation.

Conclusion: Using curcumin as a hydrophobic core is a facile and feasible strategy with bifunction of debittering as well as improving bioactive effect of SPH, which may extend its application in foods. © 2024 Society of Chemical Industry.