genetically modified foods -...
TRANSCRIPT
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Contents
Introduction ............................................................................................................................ 2
History.................................................................................................................................... 3
Genetically Modification Methods of Food ........................................................................... 4
Current genetically modified foods in the world ................................................................... 5
Benefits of Genetically Modified foods ................................................................................. 7
Disadvantages of Genetically Modified foods ....................................................................... 9
Conclusion ........................................................................................................................... 10
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Introduction
Some foods come from directly from plants or animals, but some foods need to prepare through
a recipe. In those cases the raw materials are the one being GM not the food. Genetically
modified (GM) foods are the one that has had its genetic material altered through any method
and made it enhanced. This can be accomplished by incorporating genes from other organisms
or by rearranging genes already present. These changes can result in the expression of attributes
not found in the original organism. GM foods are classified into one of three generations.
First-generation crops have enhanced input traits, such as herbicide tolerance, better
insect resistance, and better tolerance to environmental stress.
Second-generation crops include those with added-value output traits, such as nutrient
enhancement for animal feed.
Third-generation crops include those that produce pharmaceuticals, improve the
processing of bio-based fuels, or produce products beyond food and fiber.
GM foods are developed and marketed because there is some perceived advantage either to the
producer or consumer of these foods. All the GM foods are to make the foods in good quality
and for a lower price. With the current situation of the world food production this has become
a great requirement in the food industry. In the world most of the food are wasted due to the
less resistance for the microbes and diseases. The world population has topped 6 billion people
and is predicted to double in the next 50 years. Ensuring an adequate food supply for this
booming population is going to be a major challenge in the years to come. GM foods promise
to meet this need in a number of ways in the food crop cultivation GM seeds are produced by
removing the weaknesses like pest attack problems. Enhanced yield and much more
advantages.
In the past, it was possible to develop new varieties only within the same species. This was
done by making cross pollinated different crop varieties, see what desirable traits resulted, and
reproduced those hybrids. That’s how this genetically modified technology started.
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History
Genetically modified food technology started around 1950 with the selective breeding method.
Which means organisms with desired traits are used to breed the next generation and organisms
lacking the trait are not bred, is the concept of the GM technology. This was enhanced with the
time when the found of DNAs and RNAs. The first genetically modified plant was produced
in 1983, using an antibiotic-resistant tobacco plant. Genetically modified microbial enzymes
were the first application of genetically modified organisms in food production and were
approved in 1988 by the US Food and Drug Administration.
The first genetically modified food approved for release was the Flavr Savr tomato in 1994.
Developed by Calgene, it was engineered to have a longer shelf life by inserting a gene that
delayed ripening. China was the first country to commercialize a transgenic crop in 1993 with
the introduction of virus-resistant tobacco. In 1995, Bacillus thuringiensis (Bt) Potato was
approved for cultivation, making it the first pesticide producing crop to be approved. Other
genetically modified crops receiving marketing approval in 1995 were: canola with modified
oil composition, Bt maize, cotton resistant to the herbicide bromoxynil, Bt cotton, glyphosate-
tolerant soybeans, virus-resistant squash, and another delayed ripening tomato.
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Genetically Modification Methods of Food
Basically there are three general methods of genetically modifying of foods. When it comes to
foods they are made of crops, organisms and etc. so the combination of all these are called GM
foods. DNA is the basic unit of the every living being and the blueprint of the hereditary
material which carry the information of the traits.
Three general methods of Genetic Engineering,
1. The plasmid method
2. The vector method
3. The biolistic method
The plasmid method is used for microorganisms and the vector method is the same but it has
higher accuracy and results than the other methods. In the food of GM biolistic method is the
suitable one because for crops and plants this is the accurate and commonly using method.
Why is biolistic important?
Plants can be divided in to two main categories which are monocotyledon and
dicotyledonous. Some monocotyledon plants especially agricultural varieties are not flexible
to other transformation methods. For such cells and tissues biolistic is important. The cell
walls of plants are pretty tough. To get the DNA to penetrate the cell wall of the plant require
much force. By using this method can make this happen when gold or tungsten microscopic
particles coated with DNA are fired at extremely high velocity.
Biolistic Method (gene gun method)
In this method the impregnation of the cells with nucleic acid or with other biological molecules
is achieved by coating the molecules that are intended to be introduced in to the cells on to
micro carriers. For those carriers can use,
1. High density gold microparticals
2. High density tungsten micriparticals
Then a gun which specified is used to carry out the procedure. The gene gun with the help of
helium pulse accelerates these particles to extremely higher velocities. The result is they are
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able to penetrate the cell walls and membranes and finally get in to the cell. This is the simply
procedure of the biolistic method.
Current genetically modified foods in the world
1. Corn
Genetically modified corn turns up in many different products in the world and corn on the cob
is the least of it. This crop is used to produce many different ingredients used in processed
foods and drinks, including high-fructose corn syrup and corn starch. But the bulk of the GM
corn grown around the world is used to feed livestock. Some is also converted into biofuels.
And already there are 33 varieties of GM corn have been developed.
2. Soybeans
The larger crop after corn, GM soy is used mainly in animal feed and in soybean oil which is
widely used for processed foods and in restaurant and hotel chains. In fact, soybean oil accounts
for 61% of Americans' vegetable-oil consumption. But in Sri Lanka like country coconut oil
takes the place. It's also often used to make an emulsifier called soy lecithin, which is present
in a lot of processed foods, including chocolate, candy and many other foods. There are 20 GM
varieties of soybeans around the world.
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3. Cotton
Mostly cotton seed oil is made by using the GM cotton varieties, which is used for frying in
restaurants and in packaged foods like potato chips, oily spreads like margarine, even things
like cans of smoked oysters. Some parts of the plant are also used in animal feed, and what's
left over can be used to create food fillers such as cellulose. There are 16 varieties of GM cotton
around the world.
4. Papaya
Papaya is a fruit which have a low immunity on diseases. This varieties ware bred to withstand
ringspot virus, which can destroy papaya plants, these genetically engineered 'Rainbow
Papayas' were first commercially produced in the late 1990s. Much of the yield is grown in
Hawaii. There are 2 GM plants.
5. Potatoes
The very recently approved GM crop is resistant to bruising and may produce less of a cancer-
causing chemical, called acrylamide, when exposed to high heat. It has not yet seen adoption
in the food supply, but is expected to be. There are 6 varieties of GM potatoes so far.
6. Canola
GM canola is used to make oil for cooking, as well as margarine. It's also used to produce
emulsifiers that are used in packaged foods. By some estimates, 90% of canola grown in the
U.S. and Canada is GM. 2 verities of canola plans so far developed.
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7. Apples
Another newly approved crop, this apple from a Canadian biotech company does not brown
even after it's been sliced. It recently received FDA approval. The agency said it is safe to eat,
which means they may appear on supermarket shelves. One GM variety is available.
8. Sugar Beets
Half of the sugar requirement of the world comes from GM sugar beets, which have been in
production since 2008. Only one GM variety is available. The glyphosate sprayed on GM beet
fields significantly reduces weed growth.
Benefits of Genetically Modified foods
1. Pest resistance
Due to the pest problems most of the crops are destroyed. This has caused finance loses to the
farmers. To minimize the effect farmers typically use many tons of chemical pesticides
annually. Consumers do not wish to eat food that has been treated with pesticides because of
potential health hazards, and run-off of agricultural wastes from excessive use of pesticides
and fertilizers can poison the water supply and cause harm to the environment. Growing GM
foods such as B.t. corn can help eliminate the application of chemical pesticides and reduce the
cost of bringing a crop to market. This makes the crop natural and buying convenience for the
buyer.
2. Herbicide tolerance
For some crops, it is not cost effective to remove weeds by physical such as tilling, so farmers
will often spray large quantities of different herbicides to destroy weeds. This is a time
consuming and a very expensive treatment that requires care so that the herbicide doesn't harm
the crop plant or the environment. Crop plants genetically modified to be resistant to one very
powerful herbicide could help prevent environmental damage by reducing the amount of
herbicides needed. For example, Monsanto has created a strain of soybeans genetically
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modified to be not affected by their herbicide product Roundup. Likewise can reduce the effect
on the crop.
3. Disease resistance
There are many viruses, fungi and bacteria that cause plant diseases. So the farmers are able to
grow the crops without using minimum antifungal and antibiotics which are having health
effect on humans. Good effect on the economy as well by lower price those foods can enter to
the market.
4. Cold tolerance
Too low temperature or unexpected frost can destroy sensitive seedlings. An antifreeze gene
from cold water fish has been introduced into plants such as tobacco and potato. With this
antifreeze gene, these plants are able to tolerate cold temperatures that normally would kill
unmodified seedlings.
5. Drought tolerance/salinity tolerance
With the increasing rate of the world population most of the lands have been taken as homes,
so there are no enough good lands as before. Farmers will need to grow crops in locations
previously unsuited for plant cultivation. Creating plants that can withstand long periods of
drought or high salt content in soil and groundwater will help people to grow crops in formerly
inhospitable places.
6. Nutrition
Malnutrition is common in third world countries where impoverished peoples rely on a single
crop such as rice for the main staple of their diet. However, rice does not contain adequate
amounts of all necessary nutrients to prevent malnutrition. If rice could be genetically
engineered to contain additional vitamins and minerals, nutrient deficiencies could be
alleviated. As an example golden rice can be taken, which is incorporate with beta carotene
within the rice seed.
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Disadvantages of Genetically Modified foods
1. Unintended harm to other organisms
An experiment was exposed that pollen from B.t. corn caused high mortality rates in monarch
butterfly caterpillars. Monarch caterpillars consume milkweed plants, not corn, but the fear is
that if pollen from B.t. corn is blown by the wind onto milkweed plants in neighboring fields,
the caterpillars could eat the pollen and die. Unfortunately, B.t. toxins kill many species of
insect larvae indiscriminately; it is not possible to design a B.t. toxin that would only kill crop
damaging pests and remain harmless to all other insects.
2. Allergies
Many children all around world have developed life-threatening allergies to peanuts and other
foods. There is a possibility that introducing a gene into a plant may create a new allergen or
cause an allergic reaction in susceptible individuals. A proposal to incorporate a gene from
Brazil nuts into soybeans was abandoned because of the fear of causing unexpected allergic
reactions.31 Extensive testing of GM foods may be required to avoid the possibility of harm to
consumers with food allergies. Labeling of GM foods and food products will acquire new
importance, which I shall discuss later.
3. Unknown effects on human health
There is a growing concern that introducing foreign genes into food plants may have an
unexpected and negative impact on human health. A recent article published in Lancet
examined the effects of GM potatoes on the digestive tract in rats.32,33 This study claimed
that there were appreciable differences in the intestines of rats fed GM potatoes and rats fed
unmodified potatoes. Yet critics say that this paper, like the monarch butterfly data, is flawed
and does not hold up to scientific scrutiny.34 Moreover, the gene introduced into the potatoes
was a snowdrop flower lectin, a substance known to be toxic to mammals. The scientists who
created this variety of potato chose to use the lectin gene simply to test the methodology, and
these potatoes were never intended for human or animal consumption.
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Conclusion
An increasing set of evidence has been reported on how consumers could potentially react to
the introduction of genetically modified food. Studies typically contain some empirical
evidence and some theoretical explanations of the data, however, to date limited effort has been
posed on systematically reviewing the existing evidence and its implications for policy. This
paper contributes to the literature by bringing together the published evidence on the behavioral
frameworks and evidence on the process leading to the public acceptance of genetically
modified (GM) food and organisms (GMOs). In doing so, we employ a set of clearly defined
search tools and a limited number of comprehensive key words. The study attempts to gather
an understanding of the published findings on the determinants of the valuation of GM food –
both in terms of willingness to accept and the willing-to-pay a premium for non-GM food, trust
with information sources on the safety and public health and ultimate attitudes underpinning
such evidence. Furthermore, in the light of such evidence, we formulate some policy strategies
to deal with public uncertainly regarding to GMOs and, especially GM food.
A genetically modified organism (GMO) is one that has had its genetic material altered through
one of several methods. Although traditional animal breeding and genetic modification through
plant hybridization techniques are technically genetic modifications, these techniques pre-date
recombinant techniques and typically are not considered GM. A genetically engineered (GE)
organism is one where its DNA is modified using techniques that permit the direct transfer or
removal of genes in that organism. Organisms that undergo genetic engineering are sometimes
referred to as transgenic. Originally transgenic referred to an organism that had a gene from
another (different) organism inserted into its genetic material; however, especially in news
articles and on the Internet, the term transgenic frequently is used to refer to any genetic
modification, regardless of the source and recipient of genetic material.
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References
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Smith, N. 2000. “Seeds of Opportunity: An Assessment of the Benefits, Safety, and
Oversight of Plant Genomics and Agriculture Biotechnology.” 106th Cong., 2nd sess.
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http://calag.ucanr.edu/Archive/ ?article=ca.v054n04p6.
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