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Biosafety of foods derived by modern biotechnology

FOOD ACQUISITION, production, modification, and processing technologies form a continuum of allied biotechnologies which trace back to the beginnings of agriculture. These technologies have made use of naturally-occurring genetic variation in an effort to create variety and expand the reach of food sources. Common know variation among and within agricultural commodities has become accepted and expected in human societies.

Rapid technological advance in biology has resulted in the development of new agricultural tools, such as recombinant DNA technology. These technologies may expand the scope of current sources of variation and shorten the time to development for agricultural commodities, and in addition present new opportunities for genetic recombination and the appearance of novel gene products.

Public concern over the safety of foods derived from modern biotechnology prompted comprehensive examination of this issue by the International Food Biotechnology Council (IFBC) in 1990. This work resulted in the development of tiered decision trees for determining food safety issues for foods derived from microorganisms, single chemicals and simple mixtures, and whole foods and other complex mixtures. Decision trees consider the genetic origin, composition, and safety of the food; resulting in a decision to accept, reject, or further study the test material. The council’s recommendations stated that food safety evaluations should be closely linked to existing agricultural and processing practices as well as estimation of the regulatory status of comparable foods.

Sabir Hussain Shah

The introduction of significant amounts of genetic variation, whether by natural or foreign means, makes the improvement of numerous desirable traits possible. In addition, this genetic variation has allowed for the production of diverse food sources and a diverse selection of choices within each of these sources.  Breeders have, for example, developed varieties of fruits, vegetables, and grains with widely varying characteristics, such as seedless and seeded red, green, and white grapes, and green, red, and yellow apples with a myriad of processed uses.

Technologies which make use of and manipulate this variation by and large have been judged inherently safe by humankind. Human societies have come to appreciate and expect natural variation for color, flavor, texture, season, and end-use in their food sources. This natural variation forms the basis of a diverse and well-rounded food supply.

Biotechnology identified seven main parts of a standard safety test which are: study of the introduced DNA and the new proteins or metabolites that it produces; analysis of the chemical composition of the relevant plant parts, measuring nutrients, anti-nutrients as well as any natural toxins or known allergens; assess the risk of gene transfer from the food to microorganisms in the human gut; study the possibility that any new components in the food might be allergens; estimate how much of a normal diet the food will make up; estimate any toxicological or nutritional problems revealed by the data; additional animal toxicity tests if there is the possibility that the food might pose a risk.

Safety evaluation for food derived from genetically modified microorganisms focus on question as such as whether the microorganism ends up in the food, whether it is free of transmissible antibiotic resistance markers, whether the vectors are free of attributes that would make them unsafe in food, whether the DNA might code for a toxic product, or whether the food is free of antibiotics and toxins produced by related microbial strains. Expression of new gene products in safe microbial hosts should be evaluated. If the gene product is already part of the food chain, little testing is necessary.

Introgression of a well-characterized gene form a complex uncharacterized genome into a defined system may negatively or positively affect the safety of the food product. Vector design has been identified as a critical factor in maintaining the safety of antibiotic resistance markers which may be used for identifying transformed segments of DNA.

In most cases, toxin production by microorganisms poses no risk following introduction of a gene which does not produce a toxin. Single chemicals and simple chemical mixtures were not found to require any new or additional testing measures since they generally contain safe levels of all undesirable compounds.

In addition, these are typically consumed at low levels compared to whole foods. Safety evaluation of genetically modified plant products, microorganisms, and macro ingredients should be based on comparisons with traditional counterparts for nutrient content, various expression products, and toxins. If the source of genetic material for whole foods in another food product, it is likely the confidence in its safety will be increased.

The standard for compositional comparison for safety must be considered in the range that is normal in any closely related traditional foods. When data from such studies do not establish the safety of a food, feeding studies in animals are recommended. If a foot contains sufficient quantities of constituents with no dietary history, toxicological testing may be advised. If individual compounds cannot be isolated in sufficient quantity to test their safety in animal studies, the whole food may be used in such a test.

New technologies may expand the range of current sources of variation and shorten development time for agricultural commodities, while at the same time present new opportunities for appearance of novel gene products that represent a significant step toward evaluation of food safety issues in the era of modern biotechnology.

Source:http://www.technologytimes.pk