High carotenoid bioaccessibility through linseed oil nanoemulsions with enhanced physical and oxidative stability

Abstract

Carotenoid (astaxanthin or lycopene) emulsions obtained by high pressure homogenization were investigated for their physical, oxidative and storage stability and biological fate on an in vitro digestion model of bioaccessibility. Emulsion stability evaluated at various processing environments (20–50°C, 2–10 pH, 0–500mM NaCl, and 0–35days storage at 25°C) depended on carotenoid and homogenization pressures (5, 10, 100MPa). Trolox increased the oxidative stability of nanoemulsions (100MPa) and acted synergistically with BHT in increasing the stability of lycopene nanoemulsion. Intestinal digestibility depended on homogenization pressures with the fastest release and lower amount of free fatty acids observed at 100MPa. Carotenoid nanoemulsions (100MPa) were partially (66%) digested and highly bioaccessible (>70%). Therefore, nanoemulsions provide an effective and stable system for efficient astaxanthin or lycopene delivery and bioavailability in foods, beverages, nutraceuticals and/or other agriproducts.