title: Prooxidative and antioxidative properties of β-carotene in chlorophyll and riboflavin photosensitized oil-in-water emulsions.
abstract: Effects of β-carotene on the oxidative stability of chlorophyll or riboflavin photosensitized oil-in-water (O/W) emulsions were determined by analysing the depleted headspace oxygen content, lipid hydroperoxides, fluorescence intensity, and headspace volatiles. As the concentration of β-carotene increased from 0 to 10, 100, and 1000 μM, the oxidative stability of samples containing chlorophylls decreased in a concentration-dependent manner under light, indicating that β-carotene acted as a prooxidant. However, in riboflavin photosensitized O/W emulsions, 100 and 1000 μM β-carotene inhibited lipid oxidation. Although β-carotene protected both photosensitisers in O/W emulsions, β-carotene displayed antioxidative or prooxidative properties, which depended on the polarity of the photosensitisers. The development of t-2-heptenal and 1-octen-3-ol increased greatly in chlorophyll sensitised O/W emulsions with an increase in β-carotene concentration, implying that more singlet oxygen oxidation occurred due to the higher levels of remaining chlorophylls. However, the content of t-2-heptenal and 1-octen-3-ol in the riboflavin sensitised O/W emulsions was not significantly correlated with the β-carotene concentration, which indicates that β-carotene in the lipid particles effectively quenched singlet oxygen.
authors.affiliation: Department of Food Science and Biotechnology, Sungkyunkwan University, Suwon, Republic of Korea.
authors.forename: JungWoo
authors.initials: J
authors.lastname: Park
authors.forename: Tae Soo
authors.initials: TS
authors.lastname: Kim
authors.forename: Mi-Ja
authors.initials: MJ
authors.lastname: Kim
authors.forename: JaeHwan
authors.initials: J
authors.lastname: Lee
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D002734:Chlorophyll / Q000737:chemistry*; D004655:Emulsions / Q000737:chemistry; D008027:Light; D009821:Oils / Q000737:chemistry; D010083:Oxidants, Photochemical / Q000737:chemistry*; D010084:Oxidation-Reduction / Q000528:radiation effects; D012256:Riboflavin / Q000737:chemistry*; D026082:Singlet Oxygen / Q000737:chemistry; D014867:Water / Q000737:chemistry; D019207:beta Carotene / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D004655:Emulsions; D009821:Oils; D010083:Oxidants, Photochemical; D019207:beta Carotene; D014867:Water; D002734:Chlorophyll; D026082:Singlet Oxygen; D012256:Riboflavin