Soy protein hydrogels with filler emulsion particles coated by hydrolyzed protein

The growing consumer preference for plant-based foods in recent years has spurred research efforts to enhance the structural attributes of plant proteins, addressing the limitations associated with animal-source proteins in terms of sustainability. This includes endeavors to improve the gelling and emulsifying properties of plant proteins. The selective enzymatic hydrolysis of soy protein isolate using pepsin and papain resulted in distinct alterations in the hydrolysate compositions. NSPI (native soy protein isolate) encompassed all beta-conglycinin and glycinin subunits as a baseline for the comparison. SPHPe (soy proteins hydrolyzed by pepsin) exhibited low molecular weight peptides and beta-conglycinin, while SPHPa (soy proteins hydrolyzed by papain) primarily featured peptides below 20 kDa. SPHPe, characterized by a higher beta-conglycinin ratio, demonstrated excellent emulsifying activity and stability compared to SPHPa, which displayed weaker performance. Emulsion-filled gels with SPHPe exhibited the highest gel strength and water-holding capacity, forming denser gels primarily influenced by hydrophobic interactions. Thus, exploring active emulsion-filled gels via enzymatic digestion presents a promising avenue for developing meat substitutes and animal-free food alternatives, offering innovative applications for plant proteins across diverse food products. This study highlights that soy protein with pepsin-derived hydrolysis (SPHPe) enhances its emulsifying properties, and gels filled with SPHPe emulsion exhibit a significant increase in gel strength and water-holding capacity.