**3.1. Relationship between casein composition and emulsion interfacial properties**

Caprine caseins have markedly higher content of β-casein than bovine casein. The specific oxidative stability found in emulsified lipids has been explained by the formation of a highly protective interface produced from β-casein as an emulsifier in the emulsions [23, 24]. Likewise, emulsions exert good protective effects on the carotenoids. Thus, it has been reported that the multilayer emulsions around the oil droplets can potentially reduce the amount of light reaching the carotenoid [19, 20]. A lutein dispersion was achieved using bovine casein or caprine caseins (caprine αs1-I-casein and caprine αs1-II-casein) as emulsifier in an emulsion beverage [19, 20]. The caprine casein emulsifier, in particular caprine αs1-II-casein, in combination with arabinogalactan, a water-soluble polysaccharide, is noteworthy because this lutein dispersion system remains stable after light exposure during storage [20].
