Dépôt numérique

Polyphenols in cocoa: influence of processes on their composition and biological activities

Lacroix, Monique ORCID logoORCID: https://orcid.org/0000-0002-2042-4033 (2010). Polyphenols in cocoa: influence of processes on their composition and biological activities In: Chocolate, Fast Foods and Sweeteners: Consumption and Health. Food and Beverage Consumption and Health . Nova Science Publishers, Inc., Portland, OR, pp. 183-197.

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Cocoa and cocoa products, namely cocoa liquor, cocoa powder and chocolates (milk and dark chocolates) may present varied polyphenol contents and possess different levels of antioxidant potentials. Those products are an important source of polyphenols. The content of polyphenols in cocoa powder is between 12-18% of its total wt. on dry basis. The major phenolic compds. are epicatechin, proanthocyanidins and catechin. The bioavailability of these compds. depends on other food constituents, and their interaction with the food matrix. Some of the identified benefits of phenolic-rich cocoa and chocolate include antioxidant properties, reduced blood pressure via the induction of nitric-oxide (NO)-dependent vasodilation in human and flow-mediated dilation of the brachial artery, improvement of endothelial function, vasoprotective, prevention of cancer and blood pressure - lowering effects, improvement of blood flow regulation, prevention of cardiovascular disease, prevention of diabetes, improvement of insulin sensitivity, a decrease of platelet activation and function, treatment of glaucoma as well as a modulation of immune function and inflammation. Phenolic-rich cocoa and chocolate may also exert a protective effect on low-d. lipoprotein (LDL) oxidn., which has been assocd. with a reduced risk of developing atherosclerosis. Inhibition of DNA synthesis, modulation of ROS prodn., regulation of cell cycle arrest, modulation of survival/proliferation pathways are the most important mechanisms that can exert chemopreventive effects towards different organ specific cancers. In addn., polyphenols can directly influence different points of the apoptotic process, and/or the expression of regulatory proteins. Cocoa can contain a high concn. of flavanols, catechins and procyanidins which have been reported to have strong antioxidative activity. Epicatechin seem to be absorbed much more than catechin. However, catechins have shown a bioavailability of approx. 25-30% of ingested catechins in urine. These flavonoids have potent antioxidant and antiplatelet activities following consumption of cocoa or chocolate. After oral supplementation, they are present in blood as metabolites such as glucuronides and/or sulfate conjugated and/or methylated forms. In acute feeding studies, flavanol-rich cocoa and chocolate increased plasma antioxidant capacity and reduced platelet reactivity. According to some studies, 150 mg of flavonoids is needed to trigger a rapid antioxidant effect and changes in prostacyclin. Some dose-response evidence demonstrates an antioxidant effect with approx. 500 mg flavonoids. The antioxidants in cocoa can prevent the oxidn. of LDL-cholesterol, related to the mechanism of protection in heart disease. (-)-Epicatechin and other cocoa flavan-3-ols have shown good cardiovascular protection. These compds. reported to decrease the plasma concns. of proinflammatory cysteinyl leukotrienes. They also inhibit low-d. lipoprotein oxidn., reduce thrombosis, improve endothelial function, and reduce inflammation. However, cocoa beans from different countries of origins and the methods of prepn. (primary and secondary) could partially influence the antioxidant polyphenols of cocoa products.

Type de document: Chapitre de livre
Mots-clés libres: -
Centre: Centre INRS-Institut Armand Frappier
Date de dépôt: 01 avr. 2024 02:01
Dernière modification: 01 avr. 2024 02:01
URI: https://espace.inrs.ca/id/eprint/14239

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