Comparative studies of loading lipophilic substances into casein micelles and investigating the influence of whey proteins and heat treatment on loading stability

Application of casein micelles ( CM ) as nanocarriers for lipophilic substances was studied. Casein micelles were separated from skimmed milk by microfiltration. Casein micelles were partly dissociated at 2 °C, pH 5.5, and loaded with β‐carotene, vitamin D2 or docosahexaenoic acid ( DHA ). Loading concentrations and times were varied. Loading efficiency was in the order: β‐carotene > vitamin D2 > DHA . Optimal loading times were 60 min for β‐carotene and 15 min for vitamin D2 and DHA . Adding whey protein to loaded CM led to lower vitamin D2 content in the micellar phase. Heat treatment (85 °C/2 min) led to stable loading concentrations over 4 days of storage.