Effects of adding low levels of a disulfide reducing agent on the disulfide interactions of β-Lactoglobulin and κ-Casein in skim milk

Nguyen H.A. Nguyen (1) , Marie Wong (2) , Skelte G. Anema (3) , Palatasa Havea (3) , Fanny Guyomarc'H (4)

1 Institute of food, Nutrition and Human health
2 Institute of Food Nutrition and Human Health
3 Fonterra Research Centre
4 STLO - Science et Technologie du Lait et de l'Oeuf

Low concentrations of a disulfide reducing agent were added to unheated and heated (80 °C for 30 min) skim milk, with and without added whey protein. The reduction of the β-lactoglobulin and κ-casein disulfide bonds was monitored over time using electrophoresis. The distribution of the proteins between the colloidal and serum phases was also investigated. κ-Casein disulfide bonds were reduced in preference to those of β-lactoglobulin in both unheated and heated skim milk (with or without added whey protein). In addition, in heated skim milk, while the serum κ-casein was reduced more readily than the colloidal κ-casein, the distribution of κ-casein between the two phases was not affected.

Mots clés: κ-Casein; β-lactoglobulin; skim milk; disulfide reducing agent; disulfide bonds; disulfide

Domaines: Ingénierie des aliments

Nguyen H.A. Nguyen, Marie Wong, Skelte G. Anema, Palatasa Havea, Fanny Guyomarc'H. Effects of adding low levels of a disulfide reducing agent on the disulfide interactions of β-Lactoglobulin and κ-Casein in skim milk. Journal of Agricultural and Food Chemistry, 2012, 60 (9), pp.2337-2342. ⟨10.1021/jf205297p⟩. ⟨hal-01209306⟩