Flavonoid-Rich Dark Chocolate Improves Endothelial Function and Increases Plasma Epicatechin Concentrations in Healthy Adults
Journal of the American College of Nutrition, Vol. 23, No. 3, 197–204 (2004)
Dark chocolate derived from the plant (Theobroma cacao) is a rich source of flavonoids. Cardioprotective effects including antioxidant properties, inhibition of platelet activity, and activation of endothelial nitric oxide synthase have been ascribed to the cocoa flavonoids.
Conclusion: Flavonoid-rich dark chocolate improves endothelial function and is associated with an increase
in plasma epicatechin concentrations in healthy adults. No changes in oxidative stress measures, lipid profiles,
blood pressure, body weight or BMI were seen.
Procyanidin and catechin contents and antioxidant capacity of cocoa and chocolate products.
Gu L, House SE, Wu X, Ou B, Prior RL. Arkansas Children's Nutrition Center, ARS-USDA, and Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72202, USA.
Cocoa and chocolate products from major brands were analyzed blind for total antioxidant capacity (AOC) (lipophilic and hydrophilic ORAC(FL)), catechins, and procyanidins (monomer through polymers). Accuracy of analyses was ascertained by comparing analyses on a NIST standard reference chocolate with NIST certified values. Procyanidin (PC) content was related to the nonfat cocoa solid (NFCS) content. The natural cocoa powders (average 87% of NFCS) contained the highest levels of AOC (826 +/- 103 micromol of TE/g) and PCs (40.8 +/- 8.3 mg/g). Alkalized cocoa (Dutched powders, average 80% NFCS) contained lower AOC (402 +/- 6 micromol of TE /g) and PCs (8.9 +/- 2.7 mg/g). Unsweetened chocolates or chocolate liquor (50% NFCS) contained 496 +/- 40 micromol of TE /g of AOC and 22.3 +/- 2.9 mg/g of PCs. Milk chocolates, which contain the least amount of NFCS (7.1%), had the lowest concentrations of AOC (80 +/- 10 micromol of TE /g) and PCs (2.7 +/- 0.5 mg/g). One serving of cocoa (5 g) or chocolate (15 or 40 g, depending upon the type of chocolate) provides 2000-9100 micromol of TE of AOC and 45-517 mg of PCs, amounts that exceed the amount in a serving of the majority of foods consumed in America. The monomers through trimers, which are thought to be directly bioavailable, contributed 30% of the total PCs in chocolates. Hydrophilic antioxidant capacity contributed >90% of AOC in all products. The correlation coefficient between AOC and PCs in chocolates was 0.92, suggesting that PCs are the dominant antioxidants in cocoa and chocolates. These results indicate that NFCS is correlated with AOC and PC in cocoa and chocolate products. Alkalizing dramatically decreased both the procyanidin content and antioxidant capacity, although not to the same extent.
Flavanol and Flavonol Contents of Cocoa Powder Products: Inﬂuence of the Manufacturing Process
C. ANDRES-LACUEVA, M. MONAGAS, N. KHAN, M. IZQUIERDO-PULIDO, M. URPI-SARDA, J. PERMANYER, AND R. M. LAMUELA-RAVENT ´ OS* J. Agric. Food Chem. 2008, 56, 3111–3117 3111
Major brands of cocoa powder products present in the Spanish market were analyzed for monomeric ﬂavanols [(+)-catechin and (-)-epicatechin] and ﬂavonols [quercetin-3-glucuronide, quercetin-3-glucoside (isoquercitrin), quercetin-3-arabinoside, and quercetin]. In addition, the inﬂuence of the manufacturing process of cocoa powder products, in particular, the alkalinization treatment (Dutching), on the original content of these ﬂavonoids has been studied. (-)-Epicatechin was in the range of 116.02–730.26 µg/g, whereas (+)-catechin was in the range of 81.40–447.62 µg/g in the commercial cocoa products studied. Among ﬂavonols, quercetin-3-arabinoside and isoquercitrin were the major ﬂavonols in the cocoa powder products studied, ranging from 2.10 to 40.33 µg/g and from 3.97 to 42.74 µg/g, respectively, followed by quercetin-3-glucuronide (0.13–9.88 µg/g) and quercetin aglycone (0.28–3.25 µg/g). To our knowledge, these results are the ﬁrst quantitative data in relation to the content of individualized ﬂavonol derivatives in commercial cocoa powder products. The alkalinization treatment resulted in 60% loss of the mean total ﬂavonoid content. Among ﬂavanols, (-)-epicatechin presented a larger decline (67%, as a mean percentage difference) than (+)-catechin (38%), probably because of its epimerization into (-)-catechin, a less bioavailable form of catechin. A decline was also conﬁrmed for di-, tri-, and tetrameric procyanidins. In the case of ﬂavonols, quercetin presented the highest loss (86%), whereas quercetin-3-glucuronide, quercetin-3-arabinoside, and isoquercitrin showed a similar decrease (58, 62, and 61%, respectively). It is concluded that the large decrease found in the ﬂavonoid content of natural cocoa powder, together with the observed change in the monomeric ﬂavanol proﬁle that results from the alkalinization treatment, could affect the antioxidant
properties and the polyphenol biovailability of cocoa powder products.
KEYWORDS: Cocoa powder; catechin; epicatechin; ﬂavonols; quercetin; alkalinization
Epicatechin mediates beneficial effects of flavanol-rich cocoa on vascular function in humans
PNAS January 24, 2006, Hagen Schroeter*, Christian Heiss, Jan Balzer, Petra Kleinbongard, Carl L. Keen*, Norman K. Hollenberg**, Helmut Sies¶, Catherine Kwik-Uribe††, Harold H. Schmitz††, and Malte Kelm§
Epidemiological and medical anthropological investigations suggest that ﬂavanol-rich foods exert cardiovascular health beneﬁts. Endothelial dysfunction, a prognostically relevant key event in atheroscle- rosis, is characterized by a decreased bioactivity of nitric oxide (NO) and impaired ﬂow-mediated vasodilation (FMD). We show in healthy male adults that the ingestion of ﬂavanol-rich cocoa was associated with acute elevations in levels of circulating NO species, an enhanced FMD response of conduit arteries, and an augmented microcirculation. In addition, the concentrations and the chemical proﬁles of circulating ﬂavanol metabolites were determined, and multivariate regression analyses identiﬁed (-)-epicatechin and its metabolite, epicatechin-7-O-glucuronide, as independent predictors of the vascular effects after ﬂavanol-rich cocoa ingestion. A mixture of ﬂavanols-metabolites, resembling the proﬁle and concentration of circulating ﬂavanol compounds in plasma after cocoa ingestion, induced a relaxation in preconstricted rabbit aortic rings ex vivo, thus mimicking acetylcholine-induced relaxations. Ex vivo ﬂavanol-induced relaxation, as well as the in vivo increases in FMD, were abolished by inhibition of NO synthase. Oral administration of chemically pure (-)-epicatechin to humans closely emulated acute vascular effects of ﬂavanol-rich cocoa. Finally, the concept that a chronic intake of high-ﬂavanol diets is associated with prolonged, augmented NO synthesis is supported by data that indicate a correlation between the chronic consumption of a cocoa ﬂavanol-rich diet and the augmented urinary excretion of NO metabolites. Collectively, our data demonstrate that the human ingestion of the ﬂavanol (-)-epicatechin is, at least in part, causally linked to the reported vascular effects observed after the consumption of ﬂavanol-rich cocoa.
Epicatechin content and antioxidant capacity of cocoa beans from four different countries
African Journal of Biotechnology Vol. 9(7), pp. 1052-1059, 15 February, 2010 , Azizah Othman1, Abbe Maleyki Mhd Jalil2, Kong Kin Weng2, Amin Ismail2,3*, Nawalyah Abd.Ghani2 and Ilham Adenan4
Natural antioxidant has received more attention to be part of daily diet. Cocoa beans is one of the main sources of polyphenols especially epicatechin. This study was conducted to investigate the relationship between antioxidant potential and epicatechin content of raw cocoa beans from different countries, namely Malaysia, Ghana, Cote d’Ivoire and Sulawesi (Indonesia). Antioxidant potential was determined using trolox-equivalent antioxidant capacity (TEAC) and ferric reducing antioxidant power (FRAP) assays. Reversed-phase high performance liquid chromatography (HPLC) was used to quantify the amount of epicatechin. The epicatechin content of raw cocoa beans was in the range of 270 - 1235 mg/100 g cocoa beans. Based on the two assays, Sulawesian beans exhibited the highest antioxidant capacity followed by Malaysian, Ghanaian and Cote d’Ivoirian beans for both extracts. Both ethanolic (r= 0.92) and water (r = 0.90) extracts of cocoa beans showed a significant positive and high correlation between epicatechin and TEAC value. Similarly, FRAP assay also showed a positive and high correlation with epicatechin for both ethanolic (r = 0.84) and water (r = 0.79) extracts. Results indicated that antioxidant capacity using two different antioxidant assays exhibited a positive and high correlation with epicatechin content in cocoa beans. Thus, epicatechin content in cocoa beans could be responsible for the antioxidant capacity.