The impact of genetic modification of human foods in the 21st century: a review.

Genetic engineering of food is the science which involves deliberate modification of the genetic material of plants or animals. It is an old agricultural practice carried on by farmers since early historical times, but recently it has been improved by technology. Many foods consumed today are either genetically modified (GM) whole foods, or contain ingredients derived from gene modification technology. Billions of dollars in U.S. food exports are realized from sales of GM seeds and crops. Despite the potential benefits of genetic engineering of foods, the technology is surrounded by controversy. Critics of GM technology include consumer and health groups, grain importers from European Union (EU) countries, organic farmers, environmentalists, concerned scientists, ethicists, religious rights groups, food advocacy groups, some politicians and trade protectionists. Some of the specific fears expressed by opponents of GM technology include alteration in nutritional quality of foods, potential toxicity, possible antibiotic resistance from GM crops, potential allergenicity and carcinogenicity from consuming GM foods. In addition, some more general concerns include environmental pollution, unintentional gene transfer to wild plants, possible creation of new viruses and toxins, limited access to seeds due to patenting of GM food plants, threat to crop genetic diversity, religious, cultural and ethical concerns, as well as fear of the unknown. Supporters of GM technology include private industries, research scientists, some consumers, U.S. farmers and regulatory agencies. Benefits presented by proponents of GM technology include improvement in fruit and vegetable shelf-life and organoleptic quality, improved nutritional quality and health benefits in foods, improved protein and carbohydrate content of foods, improved fat quality, improved quality and quantity of meat, milk and livestock. Other potential benefits are: the use of GM livestock to grow organs for transplant into humans, increased crop yield, improvement in agriculture through breeding insect, pest, disease, and weather resistant crops and herbicide tolerant crops, use of GM plants as bio-factories to yield raw materials for industrial uses, use of GM organisms in drug manufacture, in recycling and/or removal of toxic industrial wastes. The potential risks and benefits of the new technology to man and the environment are reviewed. Ways of minimizing potential risks and maximizing the benefits of GM foods are suggested. Because the benefits of GM foods apparently far outweigh the risks, regulatory agencies and industries involved in GM food business should increase public awareness in this technology to enhance worldwide acceptability of GM foods. This can be achieved through openness, education, and research.

Influence of heat processing of African yam bean seed (Sphenostylis stenocarpa) flour on the growth and organ weights of rats.

The influence of heat processing of African yam bean seed flour on the growth and organ weights of rats was studied. Body weight change, feed utilization and feed conversion ratio were improved by heat processing. All rats significantly (p < or = 0.05) gained weight except those fed raw African yam bean and basal diets (diets 3 and 1 respectively). Raw African yam bean diet decreased the growth of rats and had negative effect on the organ weights especially the pancreas which was enlarged. The results indicate that heat processing improved the growth of rats and organ weights due to heat inactivation of toxic factors especially trypsin inhibitors.

Changes in some antinutrients of cowpeas (Vigna unguiculata) processed with 'kanwa' alkaline salt.

The effect on several anti-nutritional factors in cowpeas (Vigna unguiculata L. Walp) was investigated following treatment at 100 degrees C or 121 degrees C with solutions (0.1% w/v) of kanwa rock salt or NaHCO3 in distilled water. The concentration of polyphenols, calculated as tannic acid, was reduced substantially up to 67% under the alkaline conditions employed, but the reduction appeared to be greater (69-79%) at higher temperature. The loss of phytic acid was greater (27-40%) when beans were cooked in NaHCO3 than in kanwa (11-29%). The concentration of reducing sugars was decreased in all treatment groups especially under alkaline conditions. There was no evidence for the formation of lysinoalanine in any of the samples.