Cocoa polyphenols

There are two important sources of brown polyphenols, cocoa and tea, used as colorants for foods. Both are very old and date back to antiquity. 

WEISBURGER J H (2001) Chemopreventive effects of cocoa polyphenols of chroitic diseases , Exp Biol Med, 226 (10), 891-7. 

RICHELLE M, TAVAZZi I, OFFORD E (2001) Comparison of the antioxidant activity of commonly consumed polyphenolic beverages (coffee, cocoa, and tea) prepared per cup serving , J Agric Food Chem, 49 (7) 3438-42. 

With the death of the bean, cellular structure is lost, allowing the mixing of water-soluble components that normally would not come into contact with each other. The complex chemistry that occurs during fermentation is not fully understood, but certain cocoa enzymes such as glycosidase, protease, and polyphenol oxidase are active. In general, proteins are hydrolyzed to smaller proteins and amino acids, complex glycosides are split, polyphenols are partially transformed, sugars are hydrolyzed, volatile acids are formed, and purine alkaloids diffuse into the bean shell. The chemical composition of both unfermented and fermented cocoa beans is compared in Table 1. 

In live cocoa seeds, the methylxanthines are localized in polyphenolic storage cells. Bean death, which occurs 24 to 48 h after initiation of fermentation, triggers diffusion of the methylxanthines from the nib to the shell. The early studies of Humphries state that cacao cotyledons lose about 40% of their theobromine during fermentation.17 According to Knapp and Wadsworth, the loss of theobromine and caffeine becomes significant on the third day when the methylxanthines begin to diffuse into the shell.18 This migration continues until the concentration of the methylxanthines in nibs and shell are almost equal. 

Maleyki A, Jalil M and Ismail A. 2008. Polyphenols in cocoa and cocoa products is there a link between antioxidant properties and health Molecules 13 2190-2219. 

Keogh JB, Mclnemey J and Clifton PM. 2007. The effect of milk protein on the bioavailability of cocoa polyphenols. J Food Sci 72(3) S230-S233. 

Arteel GE and Sies H. 1999. Protection against peroxynitrite by cocoa polyphenol oligomers. Fed Eur Biochem Soc Lett 462(1-2) 167—170. 

Dr. Joe Vinson of the University of Scranton believes that there is something to the chocolate effect, and he came to Belmont to tell us about his intriguing research. Vinson has determined the total polyphenol content of various chocolates and has also found a way of measuring how effective these mixtures are in preventing the oxidation of human ldl in a test tube. In other words, he has calculated a phenol antioxidant index, which takes into account both the quantity and the quality of these desirable substances. At the symposium Vinson reported that cocoa powder and dark chocolate are the best, followed by milk chocolate. Instant cocoa mixes trail the field. Then Vinson delivered the kicker chocolate has more, and better, polyphenols than fruits or vegetables and more than red wine. A forty-gram bar of dark chocolate has as many polyphenols as a cup of that widely promoted antioxidant cocktail we call tea. But there is still the matter of chocolate s fat content. Researchers tell us, though, that at least half of it is stearic acid, which does not raise blood cholesterol. 

JS Bonvehi, FV Coll. Evaluation of bitterness and astringency of polyphenolic compounds in cocoa powder. Food Chem 60 365-370, 1997. 

Ca2 + transport CRAC channel Cocoa flavanols Apigenin Opuntia ficus indica polyphenols... 

Sies H, Schewe T, Heiss C, Kelm M. 2005. Cocoa polyphenols and inflammatory mediators. Am J Clin Nutr 81 304S—312S. 

The appeal of chocolate is universal, but the pleasures of eating chocolate products may perhaps be tempered by their fat and sugar content. However, in a series of human feeding studies it has been shown that the high proportion of stearic acid in the cocoa butter of chocolate does not adversely affect plasma lipids. Two recent reports of antioxidant activity have increased interest in the health aspects of chocolate an in vitro low-density liposprotein (LDL) oxidation study and a short-term in vivo study. Epicatechin, the major monomeric polyphenol antioxidant in chocolate, and an extract of chocolate liquor were both found to stimulate cellular immune response in vitro. 

The quality of the phenol antioxidants was assessed by Vinson et al. (1999) using the IC50 for LDL + VLDL (very low density lipoprotein) oxidation, with smaller values indicating a higher quality. Quality of the antioxidants was due to free-radical scavenging activity and not chelation as the concentration of polyphenols for 50% inhibition was < 1 xM and cupric ion 25 xM in the oxidation medium. There was less percent variation within the groups for this parameter than for the total polyphenol content. The quality order was dark chocolate > cocoa > milk chocolate. The dark chocolate and cocoa were significantly different from the milk chocolate (p < 0.05), but not... 

A relatively new analytical separation technique known as Ultra Performance HPLC or Ultra Performance Liquid Chromatography (UPLC ) is similar in principle to HPLC except that it uses smaller particle sizes (<2.5 pm) and higher flow rates to increase the speed of separation and peak capacity, or number of peaks resolved per unit time in gradient separations (Swartz, 2005). UPLC was used to separate and quantify six major polyphenolic compounds in cocoa with a 50 mm by 2.1 mm column with a 1.7 pm particles size and a run time of only... 

Cooper K.A. Campos-Gimenez E. Alvarez D.J. Nagy K. Donovan J.L. Williamson G. 2007. Rapid reversed phase ultra-performance liquid chromatography analysis of the major cocoa polyphenols and inter-relationships of their concentrations in ehoeolate. J. Agric. Food Chem. 55 2841-2847. 

Stahl, L. Miller, K. Apgar, J. Sweigart, D. Stuart, D. McHale, N. Ou, B. Kondo, M. Flurst, W. 2009. Preservation of cocoa antioxidant activity, total polyphenols, flavan-3-ols, and procyanidin content in foods prepared with cocoa powder. J. Food Sci. 74 C456-C461. 

An alternative that I strongly prefer is making a steaming cup of hot cocoa. Low in fat and calories, that cup of cocoa relaxes the mind and can help to lower blood pressure, thanks to its polyphenol content. See the recipe section at the end of the book for preparation tips. I personally find that I get a much better night s sleep after drinking a mug of cocoa. 

One such study came from the University of L Aquila in Italy where researchers have been busily looking into the cardiovascular benefits of the fiavonols, a type of polyphenol, that are found in cocoa products. Dr. Claudio Ferri and his colleagues, in collaboration with investigators at Tufts University in Boston, learned that flavonol-rich dark chocolate reduces blood pressure during both the day and the night in patients with hypertension. 

I ve included quite a few of my favorite recipes, frequently spiked with cocoa powder or grape juice concentrate to provide lots of flavor as well as a load of blood pressure-healthy polyphenols. Look to berries for even more polyphenols. There s no limit to the combinations of ingredients. On a happy, economical note, you ll never waste fruit when it gets a bit overripe ... 

Yup, this one s named after another frozen confection on a stick. It takes advantage of the high polyphenol content of plain cocoa powder (not hot cocoa mix). 

My wife. Dawn, is a far better baker than I am, since she likes to follow recipes to the letter and I tend to wing it. Baking calls for strict adherence to directions, but this recipe is easy enough even for me to follow without messing it up. Even so, it tastes better when Dawn makes this cake for me—it s the love factor. Beyond the sheer indulgence, you ll get the polyphenols of cocoa and the good fats. 

Here s a dessert that combines the blood pressure benefits of potassium in a banana with the polyphenols of cocoa. 

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