Food Safety

Genetically Modified Foods

What are genetically modified (GM) foods?
Genetically modified organisms(GMOs) can be definded as organisms in which the genetic material (DNA) has been altered in a way that does not occur naturally. Genes are being combined from different genes. Such technology is also known as reconbinant DNA technology. Other terms also include 'modern biotechnology', 'gene technology' or 'genetic engineering'. The resulting organisms is said to be 'genetically modified'. This technology allows selected individual genes to be transferred form one organism into another, also between non-related species.
Examples of GM products includes medicines and vaccines, foods and food ingredients, feeds and fibers. Crops that are commonly genetically modified are maize, soybeans, rice, potatoes etc.

These technologies offer dramatic promise for meeting some areas of greatest challenge for the 21st century. They also have some risks, both known and unknown.
Controversies surrounding GM foods and crops commonly focus on:
- Human and environmental safety
- Labelling and consumer choice.
- Intellectual property rights.
- Ethnics
- Food security
- Poverty reduction
- Environmental conservation

Why are GM foods produced?
GM foods is meant to translate into a rpoduct with a lower price, greater benefit (in terms of durability or nutritional value. The inital objective for developing plants based on GM organisms was to improve crop protection. The GM crops currently on market are aimed at an increased level of crop protection through the introduction of resistance against plant diseases caused by insects or viruses or increased tolerance towards herbicides.




Those crops are achieved by incorporating into the food plant with the genes for toxin production from bacterium Bacillus thuringiensis (Bt). This toxin is currently used as conventional insecticides in agriculture and is safe for human consumption. The insecticidal activity of commercially used Bt comes from endotoxins included in crystals formed during sporulation. The crystals of different strains of most Bts contain varying combinations of insecticial crystal proteins (ICPs), and different ICPs are toxic to different groups of insects. When ingested, the sporulated Bt cells are solubilized in the alkaline midgut of the insect, and protein toxin fragments then bind to specific molecular receptors on the midguys of susceptible insects. Pores are created in the insect gut, causing an imbalance in osmotic pressure, and the insect stops feeding and starves to death. Bt toxins are engineered in major crops, such as tomato, corm, potato, and cotton.




It is achieved through the introduction of a gene from certain viruses which cause disease in plants. It had been developed in some important crops including potatoes, wheat, corn and beans. However, virus resistance genes have not been identified in wild relatives of many crops, so genetic engineering has been employed. In 1980s, scientists femonstrated in a plant that the expression of a coat protein (CP) gene from a virus could confer resistance to that virus when it attempted to infect the plant. A large number of virus-resistant transgenic plants have been developed uisng "pathogen-derived resistance" techniques. Virus resistance makes plants less susceptible to diseases caused by such viruses, resulting in higher crop yields.




It is achieved through the introduction of a gene from a bacterium conveying resistance to some herbicides.

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