Milk phospholipids and buttermilk based composite nanosystems for enhanced stability and bioaccessibility of β-carotene

Bioaccessibility of lipophilic β-carotene is often compromised and lipid-based colloidal delivery systems (CDS) are considered effective to overcome this issue. In this study, milk phospholipid (MPL), buttermilk powder (BMP) and MPL:BMP composite-nanosystems were developed with encapsulation-efficiency of 91 ± 2.7%. Scanning electron microscopy showed spherical morphology of MPL and MPL:BMP nanosystems; slightly irregular morphology was observed in BMP nanosystems. Dynamic light scattering (DLS) for size (172±5–217 ± 2 nm) and polydispersity-index (0.24–0.37) analyses were performed. Fourier-transform infrared spectroscopy confirmed β-carotene incorporated through weak electrostatic interaction in nanosystems. The lipid peroxidation inhibition capacity of β-carotene by thiobarbituric reactive substances (TBARS) assay revealed that MPL, BMP and MPL:BMP nanosystems effectively inhibited TBARS (20.6 ± 2.9–50 ± 4.5%) formation. In vitro digestion revealed chemical stability was 82 ± 2.4% while bioaccessibility and effective-bioaccessibility was 94.8 ± 5% and 70.5 ± 3.2% in MPL:BMP nanosystems, respectively. Thus, milk-ingredients-based CDS can provide rational design for nutraceuticals application with enhanced bioaccessibility of β-carotene.