Antioxidant effect of_β-carotene on lipid peroxidation and synergism with tocopherol in an emulsified linoleic acid model system

Abstract

The antioxidant effect of beta-carotene was investigated in an emulsified linoleic acid model system with or without exposure to light. The effect of tocopherol on the antioxidant action of beta-carotene was also investigated. The antioxidant effect of beta-carotene was significant, and synergistically increased by the addition of rac alpha-tocopherol, in the dark but not in the light. It was#10; confirmed that superoxide anions (O(2)(-)) and hydrogen peroxide (H(2)O(2)) were formed during the light exposure, and that their formation could be significantly inhibited by the addition of tryptophan or mannitol, scavenger of hydroxyl radicals. These results strongly suggest direct participation of hydroxyl radicals, formed via the Haber-Weiss reaction, in the emulsified linoleic acid model system, with beta-carotene inhibition in the dark but an increase in the light. Regarding the mechanism of the antioxidant effect of beta-carotene, when beta-carotene is oxidized, the hydroperoxide in the acts as an electron acceptor and the hydroperoxide itself then decomposes.

Nutritional properties of organic and conventional beef meat at retail

“…Similarly, β ‐carotene contributes to the meat preservation against oxidation by quenching reactive oxygen species and retarding lipid and protein oxidation . It has been shown that β ‐carotene acts synergistically with α ‐tocopherol with respect to avoiding lipid peroxidation . The higher anti‐oxidant contents can be particularly beneficial for extending the shelf life of organic beef as a result of its higher concentration of easily oxidizable n‐3 PUFA …”

Purification and in vitro antioxidative effects of giant squid muscle peptides on free radical-mediated oxidative systems

“…When linoleic acid is oxidized in an emulsified model system, types of radicals present in the oxidation process can be varied depending on the light/dark conditions [29]. It is known that superoxide anion (O 2 À ) and hydrogen peroxide are formed during the light exposure, and hydroxyl radicals ( S OH) are generated according to Haber-Weiss reaction [30].…”

Antioxidant and Anti‐inflammation Activities of Ocotea, Copaiba and Blue Cypress Essential Oils in Vitro and in Vivo

“…The assay principle has been described in the literature [15]. Briefly, 0.5 g b-carotene was dissolved in 1 ml of chloroform and mixed with 6.25 ll of linoleic acid and 25 ll of Tween-20.…”