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jects dietary cholesterol is less of a determinant of cholesterol levels than the level of cholesterol-raising fatty acids in the diet.

There appears to be no information on the diterpene phytol, but there is quite a lot of information on the triterpenes including cycloartenol which is found in cocoa butter at levels around 0.01%. It is also found in rice bran oil, an edible oil used extensively in India and the Far East. Rice bran oil was found to reduce cholesterol levels, an effect which was later found to be associated with the non-saponifiable fraction which has cycloartenol as a major component. Cycloartenol is also found in olive oil, an oil also known to reduce the levels of LDL in humans. It may be concluded that the cholesterol-reducing properties of rice bran oil can be partly ascribed to the triterpene content.

The BIBRA review referred to above made an assessment of effects the above non-saponifiables were likely to have on cholesterol levels from their consumption via chocolate. The conclusions are summarized in Table 8.6.

Table 8.6 Cocoa butter non-saponifiables in chocolate.

Compound ß-Sitosterol

Stigmasterol

Camposterol

Phytol

Cycloartenol

Dose (mg/100 g chocolate)

35.0

12.6

10.5

Lowest effective dose 360 mg (healthy humans)

3500 mg (from rat study)

105 g (from mouse study)

No data

1750 mg (from rat study)

Rather disappointingly, it would seem that the quantities of the compounds that may be ingested from eating even quite high amounts of chocolate are considerably less than the amounts that are needed before an appreciable effect on levels of cholesterol in the blood might be seen. Note that in the case of b-sitosterol, the observed biological effect is on cholesterol absorption. At the low levels found in chocolate, this is unlikely to translate into an observed effect on blood cholesterol in subjects with normal levels of blood cholesterol (as distinct from those suffering from hypercholesterolaemia).

One could speculate as to whether these compounds might act synergistically. The low levels of these compounds make this rather unlikely, and results from human studies of cocoa butter and milk chocolate on blood cholesterol (41) would seem to confirm this.

Phenolic Acids in Cocoa

Over the years a variety of phenolic acids have been identified in cocoa (16), Table 8.2, Fig. 8.6). There seems to be relatively little recent information on these constituents of cocoa, although recent additions to the list have been clovamide

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Structures of some phenolic acids found in cocoa.

Structures of some phenolic acids found in cocoa.

and deoxyclovamide ((18), Fig. 8.4). There is a dearth of information on the quantities present in cocoa beans, fermented or unfermented, and even less on what is present in chocolate. This may be because these compounds were identified in the course of work on flavour aspects of cocoa and chocolate. As many of these compounds hold little interest from a flavour perspective, they have not been systematically studied or quantified in cocoa.

However, many of the compounds found in cocoa are widespread in the plant kingdom, where they are involved in general metabolic processes. Some of them are now beginning to attract interest elsewhere as potentially beneficial phytochemicals. For example, many have antioxidant properties, and this may be a major factor in providing protective effects.

Antioxidant Properties of Plant Phenolics

A good example of the focus of recent work is ferulic acid, a phenolic which has been identified in cocoa. A great deal is known about ferulic acid in terms of its metabolism in plants and its chemistry, but only recently has its antioxidant activity been investigated. Graf reviewed this in 1992 (42) and identified two main areas of interest, namely radical scavenging and ultraviolet (UV) absorption. The ability of ferulic acid to scavenge free radicals derives from its structure

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