Genetically modified food

Підготувала Надольська Каріна**

Genetically modified foods (GM foods, or biotech foods) are foods derived from genetically modified organisms (GMOs), specifically, genetically modified crops. GMOs have had specific changes

introduced into their DNA by genetic engineering techniques. These techniques are much more precise[1] than mutagenesis (mutation breeding) where an organism is exposed to radiation or

chemicals to create a non-specific but stable change. Other techniques by which humans modify food organisms include selective breeding and somaclonal variation.

Commercial sale of genetically modified foods began in 1994, when Calgene first marketed its Flavr Savr delayed ripening tomato. Typically, genetically modified foods are transgenic plant products: soybean, corn, canola, and cotton seed oil. These may have been engineered for faster growth, resistance to pathogens, production of extra nutrients, or

any other beneficial purpose. GM livestock have also been experimentally developed, although as of July 2010 none are currently on the market.While there is broad scientific consensus that food on the market derived from GM crops pose

no greater risk to human health than conventional food, critics have objected to GM foods on several grounds, including safety issues, ecological concerns, and economic concerns raised by the fact GM plants (and potentially

animals) that are food sources are subject to intellectual property law.

Genetically engineered plants are generated in a laboratory by altering their genetic makeup and are tested in the laboratory for desired qualities. This is usually done by adding one or more genes to a plant's genome using genetic engineering techniques.

Most genetically modified plants are generated by the biolistic method (particle gun) or by Agrobacterium tumefaciens mediated transformation.Once satisfactory plants are produced, sufficient seeds are gathered, and the companies producing the

seed need to apply for regulatory approval to field-test the seeds. If these field tests are successful, the company must seek regulatory approval for the crop to be marketed (see Regulation of the release of genetic modified organisms). Once that

approval is obtained, the seeds are mass produced, and sold to farmers. The farmers produce genetically modified crops, which also contain the inserted gene and its protein product.

Scientists first discovered that DNA can transfer between organisms in 1946.] The first genetically modified plant was produced in 1983, using an antibiotic-resistant tobacco plant. In 1994, the transgenic Flavr Savr tomato was approved by the FDA for marketing in the US - the modification allowed the tomato to delay ripening after picking. In the US in 1995, the following transgenic crops received marketing approval: canola with modified oil composition (Calgene), Bacillus thuringiensis (Bt) corn/maize (Ciba-Geigy), cotton resistant to the herbicide bromoxynil (Calgene), Bt cotton

(Monsanto), Bt potatoes (Monsanto), soybeans resistant to the herbicide glyphosate (Monsanto), virus-resistant squash (Asgrow), and additional delayed ripening tomatoes (DNAP, Zeneca/Peto, and Monsanto). In 2000, with the creation of

golden rice, scientists genetically modified food to increase its nutrient value for the first time.

Fruits and vegetables

3 views of the Sunset papaya cultivar, which was genetically modified to create the SunUp cultivar, resistant to PRV.Papaya has been genetically modified to resist the ringspot virus. 'SunUp' is a transgenic red-fleshed Sunset cultivar that is homozygous for the coat protein

gene of PRV; 'Rainbow' is a yellow-fleshed F1 hybrid developed by crossing 'SunUp' and nontransgenic yellow-fleshed 'Kapoho'. The New York Times stated that "in the early 1990s, Hawaii’s papaya industry was facing disaster because of the deadly papaya ringspot virus. Its single-

handed savior was a breed engineered to be resistant to the virus. Without it, the state’s papaya industry would have collapsed. Today, 80% of Hawaiian papaya is genetically engineered, and there is still no conventional or organic method to control ringspot virus."

Sugar

Structure of sucrose

The United States imports 10% of its sugar from other countries, while the remaining 90% is extracted from domestically grown sugar beet and sugarcane. Of the domestically grown sugar crops, half of the extracted sugar is derived from sugar

beet, and the other half is from sugarcane.After deregulation in 2005, glyphosate-resistant sugar beet was extensively adopted in the United States. 95% of sugar beet acres in the US were planted with glyphosate-resistant seed in 2011.Sugar

beets that are herbicide-tolerant have been approved in Australia, Canada, Colombia, EU, Japan, Korea, Mexico, New Zealand, Philippines, Russian Federation, Singapore, and USA.]The food products of sugar beets are refined sugar and molasses. Pulp remaining from the refining process is used as animal feed. The sugar produced from GM sugarbeets is

highly refined and contains no DNA or protein—it is just sucrose, the same as sugar produced from non-GM sugarbeets.

Foods made from GM animals

As of December 2012 there were no genetically modified animals approved for use as food, but a GM salmon was near FDA approval at that time.Animals (eg goat,) usually used for food production (eg

milk,) have already been genetically modified and approved by the FDA and EMA to produce non-food products (eg an anti-thrombotic protein drugs.

Cheese

Rennet is a mixture of enzymes used to coagulate cheese. Originally it was available only from the fourth stomach of calves, and was scarce and expensive, or was available from microbial sources, which often suffered from bad tastes.

With the development of genetic engineering, it became possible to extract rennet-producing genes from animal stomach and insert them into certain bacteria, fungi or yeasts to make them produce chymosin, the key enzyme in

rennet.The genetically-modified microorganism is killed after fermentation and chymosin isolated from the fermentation broth, so that the Fermentation-Produced Chymosin (FPC) used by cheese producers is identical in amino acid sequence to the animal source. The majority of the applied chymosin is retained in the whey and, at most, may be present in cheese in trace quantities. In ripe cheese, the type and provenance of chymosin used in production cannot be

determined.

Detection

Testing on GMOs in food and feed is routinely done using molecular techniques like DNA microarrays or qPCR. These tests can be based on screening genetic elements (like p35S, tNos, pat, or bar) or event-specific markers for the official GMOs (like Mon810, Bt11, or GT73). The array-based method combines multiplex PCR and array technology to screen

samples for different potential GMOs,[64] combining different approaches (screening elements, plant-specific markers, and event-specific markers).The qPCR is used to detect specific GMO events by usage of specific primers for screening

elements or event-specific markers. Controls are necessary to avoid false positive or false negative results. For example, a test for CaMV is used to avoid a false positive in the event of a virus contaminated sample.

Regulation

The regulation of genetic engineering concerns the approaches taken by governments to assess and manage the risks associated with the use of genetic engineering technology and the development and release of genetically modified

organisms (GMO). There are differences in the regulation of GMOs between countries, with some of the most marked differences occurring between the USA and Europe. Regulation varies in a given country depending on the intended use of the products of the genetic engineering. For example, a crop not intended for food use is generally not reviewed by

authorities responsible for food safety, while GM crops intended for use in human or animal food are reviewed by such authorities. Additionally, various govern the importation of GM commodities, as well as food made using GM

commodities.

Controversy

The genetically modified foods controversy is a dispute over the relative advantages and disadvantages of food derived from GMOs, genetically modified crops used to produce food and other goods, and other uses of genetically modified organisms in food production. The

dispute involves consumers, biotechnology companies, governmental regulators, non-governmental organizations and scientists. The key areas of controversy related to genetically modified (GM) food are: risk of harm from GM food, whether GM food should be labeled, the role of government regulators, the effect of GM crops on the environment, the impact of GM crops for farmers, including farmers in developing

countries, the role of GM crops in feeding the growing world population, and GM crops as part of the industrial agriculture system.