Which casein in sodium caseinate is most resistant to in vitro digestion? Effect of emulsification and enzymatic structuring. (March 2019)

• Record Type: Journal Article
• Authors: Böttger, Franziska; Dupont, Didier; Marcinkowska, Dorota; Bajka, Balazs; Mackie, Alan; Macierzanka, Adam
• Is Part Of: Food hydrocolloids. Volume 88(2019)
• Page Start: 114
• Page End: 118
• Publication Date: 2019-03
• Subjects: Digestion -- Sodium caseinate -- ELISA -- Emulsion -- Transglutaminase -- Casein; Hydrocolloids -- Periodicals; Food additives -- Periodicals; Colloïdes -- Périodiques; Aliments -- Additifs -- Périodiques; Colloids; Food additives; Periodicals; Electronic journals; 664.06
• DOI: 10.1016/j.foodhyd.2018.09.042
• Languages: English
• ISSNs: 0268-005X

Abstract

Abstract: We investigated the resistance of individual constituent casein epitopes (αS1 -, αS2 -, β- and κ-CN) in food-grade milk protein sodium caseinate (NaCN) to simulated human gastro-duodenal digestion. The influence of NaCN adsorption to the surface of oil-in-water emulsion droplets and the effect of crosslinking of the protein with enzyme transglutaminase (TG) on the proteolysis were studied by indirect ELISA. TG crosslinking rendered fragments of casein molecules significantly resistant to digestion. However, it depended on the type of casein and whether NaCN was presented in solution or emulsion. The crosslinking was found to considerably hinder the digestion of several amino acid regions in one of the major caseins of NaCN, β-CN. For αS1 - and αS2 -CN, only limited resistance to digestive enzymes was observed after NaCN had been crosslinked in solution but not (or to a limited extent) in emulsion. κ-CN proved to be the least resistant to the enzymatic hydrolysis regardless of the TG treatment. Our work shows for the first time how the digestibility of individual components of important food-grade protein ingredients can differ in a complex, colloidal food system. It also shows an example of how the digestibility can be modulated by chemical and physical structuring. Graphical abstract: Image 1 Highlights: Transglutaminase crosslinking can impact on gastrointestinal proteolysis. The crosslinking improves resistance to digestion of caseins in sodium caseinate. The resistance strongly depends on the type of constituent casein (αS1, αS2, β, κ). The resistance depends on presenting protein in either solution or emulsion.