Recent advances in caffeine and theobromine toxicities: a review.

Caffeine and theobromine are purine alkaloids widely consumed as stimulants and snacks in coffee and cocoa based foods and most often as part of ingredients in drugs. Man has enjoyed a long history of consumption of caffeine and theobromine. Recent interest in these two alkaloids, however, is centered on their potential reproductive toxicities. Caffeine and theobromine are now known to cross the placental and blood brain barrier thus potentially inducing fetal malformation by affecting the expression of genes vital in development. The developing fetus may not have developed enzymes for detoxification of these methylxanthine alkaloids via demethylation. There is a need, therefore, to protect the conceptus against 'insults' from teratogens of this nature. Apart from its reproductive toxicity, the presence of caffeine and theobromine in cocoa could limit its potentials as a nourishing food. This is an issue that needs to be addressed by nutritionists and the food industry at large. This paper discusses the natural sources, consumption and uses, toxicity and the major advances in the reproductive toxicology of caffeine and theobromine. The biosynthesis of these compounds in plants, metabolism in mammalian systems and the involvement of cytochrome P450 are reviewed and summarized. Evidence in favor of the toxicity of these compounds in experimental animals is presented with emphasis on the implications of these findings in humans. The paper concludes with a call for caution in the use of caffeine and theobromine pending further and more elaborate investigations.

Protein profiles and organoleptic properties of bread from wheat flour and full-fat or defatted fermented cocoa bean powder.

This study has shown that the protein in bread may be quantitatively increased significantly by addition of full-fat or defatted cocoa powder to white flour. The recipe in which white flour is incorporated with up to 10 percent defatted cocoa powder gives bread that is nearly as well accepted as white bread, but with a significantly higher protein content than the latter. However, organoleptic acceptability drops with increasing percentage of cocoa supplementation. The bitter taste of theobromine, which is normally present in high amounts in cocoa bean, is thought to be responsible for this problem of poor acceptability of high cocoa breads. This problem will have to be addressed in order to enhance the scope of increasing bread protein by cocoa supplementation.

Nutrient and antinutrient profiles of raw and fermented cocoa beans.

Freshly harvested cocoa bean was subjected to natural fermentation for 3, 6, 9 or 12 days. The proximate, mineral, hydrocyanate (HCN), oxalate and theobromine levels in the products were determined and compared with those of raw (unfermented) cocoa. The latter sample had the following composition: protein (N x 6.25), 17.5; lipid, 62.9; ash, 4.4; fibre, 5.9; and nitrogen-free extract (NFE), 9.3% dry matter. The effect of fermentation was variable, depending on duration and the nutrient under consideration. At day 3, protein content (17.6) was not different, but at day 6 (19.8) was higher (p <0.01), while days 9 and 12 (14.6 and 15.2, respectively) were lower (p <0.01) in comparison with the raw value. Inorganic P steadily decreased from 201.0 (raw) to 102.0 mg/100 g dry matter (day 12) but only the days 9 and 12 values were significantly different (p

Significance for humans of the nutrient contents of the dry fruit of Tetrapleura tetraptera.

The nutritional quality of the dry fruit of Tetrapleura tetraptera, a tropical deciduous forest tree with characteristic fruits, used as a spice, was assessed. The fruit shell, fruit pulp and seed contained varying amounts of nutrients such as protein, lipids and minerals, which were comparable and some were even higher than popular spices such as red pepper, onion, curry and ginger. The crude fibre content of the fruit shell was noteworthy and can be considered a good source of this nutritional factor. The distribution of crude lipids which indicated the location of the aroma of the spice, would enhance the processing of the fruit and improve its use.

Hydrocyanate, oxalate, phytate, calcium and zinc in selected brands of Nigerian cocoa beverage.

Hydrocyanate, oxalate, phytate, calcium and zinc were determined in five brands of cocoa beverage which were coded NC, BT, PN, CT and CA. Hydrocyanate ranged from 5.40 to 9.64 mg/100 g dry matter (DM), oxalate 68 to 146 mg/100 g DM, phytate 590 to 750 mg/100 g DM, calcium 28.7 to 116.4 mg/100 g DM and zinc 0.516 to 0.675 mg/100 g DM. The computed phytate:zinc, calcium:phytate and [calcium] [phytate]/[zinc] molar ratios ranged from 89 to 132, 0.80 to 3.01 and 0.64 to 3.03 respectively. The discussion is focused on toxic levels of hydrocyanate and oxalate, and the significance of the molar ratios in predicting the bioavailability of dietary zinc.

Changes in serum transferrin and iron concentrations in humans suffering from malaria with parasitaemia.

Sera from non-malarial (control) and Plasmodium falciparum-infected (malaria) subjects were assayed for transferrin and iron. The mean serum transferrin concentration in the malaria sera was found to be elevated by 44% above the control value. The mean serum iron was also raised in the malaria sera, but the increase (19%) was found to be well below that of transferrin. The mean saturation of serum transferrin with iron fell from 42 +/- 17% in the control group to 37 +/- 9% in the malaria group. It is suggested that the increase in transferrin concentration in the sera of malaria subjects probably resulted from an increase in the rate of transferrin synthesis, perhaps in response to the raised serum iron and/or the hypoxia which is known to be associated with malaria infection.