Fabrication of WPI-EGCG covalent conjugates/gellan gum double network emulsion gels by duo-induction of GDL and CaCl2 for colon-controlled Lactobacillus Plantarum delivery

In this study, we demonstrated the role of whey protein isolate (WPI)/(-)-epigallocatechin-3-gallate (EGCG) covalent conjugates/gellangum double network emulsion gels by duo-induction of glucono-δ-lactone (GDL) and CaCl2 on the digestion viability of Lactobacillus Plantarum powders. We employed a novel one-step continuous cold gelation strategy to product double network emulsion gels. The gellan gum in continuous phase was first induced by CaCl2 to form a gel in a short time. Besides, the GDL was improved covalent cross-linking between WPI-EGCG covalent conjugate Pickering particles or particle-coated oil droplets because of the slowly pH reduction. The first cross-linked gellan gum gels could be more closely integrated into the GDL-induced second gel networks with synergistic role, which promoted the formation of compact and homogeneous networks through hydrophobic interactions and disulfide bonds. Thus, the results provide a promising strategy for probiotic powders encapsulation of double network emulsion gels in oral applications of gel type foods.