title: Lutein-enriched emulsion-based delivery systems: Influence of pH and temperature on physical and chemical stability.
abstract: Lutein may be utilized in foods as a natural pigment or nutraceutical ingredient to improve eye health. Nevertheless, its use is limited by its poor water-solubility and chemical instability. We evaluated the effect of storage temperature and pH on the physical and chemical stability of lutein-enriched emulsions prepared using caseinate. The emulsions (initial droplet diameter=232 nm) remained physically stable at all incubation temperatures (5-70 °C); however the chemical degradation of lutein increased with increasing temperature (activation energy=38 kJ/mol). Solution pH had a major impact on the physical stability of the emulsions, causing droplet aggregation at pH 4 and 5. Conversely, the chemical stability of lutein was largely independent of the pH, with only a slight decrease in degradation at pH 8. This work provides important information for the rational design of emulsion-based delivery systems for a lipophilic natural dye and nutraceutical.
authors.affiliation: Department of Food Science, University of Massachusetts, Amherst, MA 01003, USA; Department of Human Nutrition and Food Science, California State Polytechnic University, Pomona, 3801 West Temple Ave, Pomona, CA 91768, USA.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Davidov-Pardo
authors.affiliation: Department of Food Science, University of Massachusetts, Amherst, MA 01003, USA.
authors.forename: Cansu Ekin
authors.initials: CE
authors.lastname: Gumus
authors.affiliation: Department of Food Science, University of Massachusetts, Amherst, MA 01003, USA; Department of Biochemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia. Electronic address: mcclements@foodsci.umass.edu.
authors.forename: David Julian
authors.initials: DJ
authors.lastname: McClements
mesh_terms: D002364:Caseins / Q000737:chemistry*; D004355:Drug Stability; D004655:Emulsions / Q000737:chemistry*; D014975:Lutein / Q000737:chemistry*; D013696:Temperature
chemical_list: D002364:Caseins; D004655:Emulsions; D014975:Lutein
keywords: Activation energy; Casein; Emulsions; Lutein; Storage stability