Flavonoids

Flavinoids are a large group of plant polyphenols. These compounds usually occur bound to sugar molecules. Phytochemicals are naturally occurring plant compounds such as cocoa, so flavinoids are also classed as phytochemicals. Some phytochemicals are thought to play a role in maintaining health, others may be toxic. Polyphenols are a broad class of antioxidant phytochemicals that are found throughout the plant kingdom. An example are procyanidins, a class of polyphenolic compounds found in several foods such as apples, almonds, barley, grapes, tea, maize, cinnamon, cocoa, peanuts, wine and strawberries. Procyanidins may act as antioxidants and modulate key biological pathways in mammals.

Epidemiological studies show that a high polyphenol diet can reduce the risk of coronary heart disease and stroke. Polyphenols inhibit the oxidation of low-density lipoproteins (LDLs). They reduce the risk of atherosclerosis developing by preventing LDL (bad cholesterol), from building plaque in the arteries, while raising the levels of HDL, the good cholesterol. Atherosclerosis may be initiated by oxidised LDL.

Flavonoids are a specific sub-class of compounds within the general flavonoid classification found in cocoa, chocolate, green tea, grapes, apples and red wine (Chocolate Information Centre).

Flavonoids are subdivided into 13 classes, based on the degree of hydroxylation and oxidation of the rings. Flavonoid types include anthocyanins (pigmented compounds), flavonols (such as quercetin), isoflavones (genistein and diadzein), flavanols (such as catechin), and proanthocyanidins or condensed tannins (Steinberg et al, 2003).

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