Main content area

Influence of protein type on oxidation and digestibility of fish oil-in-water emulsions: Gliadin, caseinate, and whey protein

Qiu, Chaoying, Zhao, Mouming, Decker, Eric Andrew, McClements, David Julian
Food chemistry 2015 v.175 pp. 249-257
antioxidants, carboxylic ester hydrolases, digestibility, digestion, emulsions, fish, fluorescence, gliadin, hydroperoxides, in vitro digestion, lipid peroxidation, oils, oxidation, oxidative stability, sodium caseinate, thiobarbituric acid-reactive substances, tryptophan, wheat, whey protein isolate
The influence of three surface-active proteins on the oxidative stability and lipase digestibility of emulsified ω-3 oils was examined: deamidated wheat gliadin (gliadin); sodium caseinate (CN); whey protein isolate (WPI). Gliadin and WPI were more effective at inhibiting lipid oxidation (hydroperoxides and TBARS) of fish oil-in-water emulsions than CN. Protein oxidation during storage was determined by measuring the loss of tryptophan fluorescence. The CN-emulsions exhibited the highest loss of tryptophan fluorescence during aging, as well as the highest amount of lipid oxidation. Potential reasons for the differences in oxidative stability of the emulsions with different proteins include differences in interfacial film thickness, protein chelating ability, and antioxidant amino acids profiles. During in vitro digestion, gliadin-stabilized emulsions had the lowest digestion rate of the three proteins. These results have important implications for using proteins to fabricate emulsion-based delivery systems for ω-3 oils.