Enhanced storage and gastrointestinal stability of spray-dried whey protein emulsions with chitosan and gum Arabic

Protein-based emulsions are widely utilized for delivering bioactives but suffer from thermodynamic instability, microbial spoilage, and gastrointestinal instability, necessitating enhancement strategies. This study explores the improvement of whey protein isolate (WPI) emulsions through chitosan (CS) coating and spray drying with maltodextrin (MD) or gum Arabic (GA). Canola oil droplets were stabilized with WPI, electrostatic coated with CS, and spray-dried. CS addition significantly increased entrapment efficiency from ∼75–78 % to ∼95–98 %, correlating with enhanced storage and gastrointestinal stability. During a 2-h gastric digestion study, CS/GA-protected powders demonstrated only 3.6 % lipolysis compared to 27.1 % for unprotected WPI emulsions, exhibiting superior gastric resistance. Under small intestinal conditions, their digestion rate constant was one-fifth of that for unprotected WPI emulsions. Furthermore, CS/GA-protected powders maintained excellent storage stability for one year. These findings highlight the potential of WPI-based emulsion powders as effective oral delivery systems for lipophilic bioactives, offering improved storage and gastrointestinal stability.