History of soya
The soya plant
(Glycine max) was cultivated in China before 3000 B.C., and was classified as
one of the five sacred crops. The first written record is a 2200 B.C. farming
manual advising Chinese farmers how to get the best from their crop. Missionaries
brought soya to Europe in the 17th century but climatic and soil conditions were
unsatisfactory. Soya was introduced in the USA in the early 19th century (originally
arriving as ballast aboard returning clipper ships), but soya farming in the USA
only expanded dramatically after World War II, when production in China was devastated.
Cultivation of soya
Soya is a frost-sensitive summer annual, and it takes
about 75-80 days for the beans to fully mature; plants may reach 1 metre high.
Seeds are borne in hairy pods which grow in clusters of three to five; each pod
contains two or three seeds, which resemble peas. When the seeds are mature, the
upright vine and foliage begin to shrivel and the leaves fall away. Harvesting
by machine must be completed before the pods shatter.
Roundup. and other
non-selective herbicides are used extensively for weed control in soya cultivation,
but they cannot be applied to weeds within growing crops because they will kill
the crop as well as the weeds. Using biotechnology, plants are being developed
that are tolerant to Roundup. herbicide; farmers will be thus able to spray
soya crops during the growing season.
Soya is now a global staple food and
about 110 million tonnes of beans are produced, mainly in the United States (50%+),
Brazil (20%), Argentina (10%) and China (8%). Individual farmer's crops are bulked
before export. European oil mills process about 15 Mt of soya beans annually,
mainly imported from the USA. Soya beans and their products account for 25% of
US agricultural exports to the EU and were worth more than $2 bn last year.
Soya as a food ingredient
About two-thirds of all manufactured food
products contain derivatives or ingredients made from soya. Before they can be
used in food products the soya beans have to be cleansed, cracked, dehulled and
rolled into flakes, which ruptures the oil cells for easy extraction. The oil
is extracted using a food-grade solvent, n-hexane - mostly for production of vegetable
oil and margarine. In its pure form as a vegetable oil, it is often used in salad
dressings and mayonnaise; as a vegetable fat it is used for baking and frying.
Soya lecithin acts as an emulsifier in some chocolate, breakfast cereals, ice
cream, sweets and margarine. Soya oil is also used in a wide variety of non-food
products eg soap, biological detergents, plastics, and CFC-free cooling agents;
the derivative glycerine is used in the manufacture of emulsifiers for skin cream
and softeners for gelatin capsules.
Soya flours were developed in the 1940s
by grinding and screening defatted flakes; these are used to increase the shelf-life
of many products and improve the colour of pastry crusts; the flour is free of
gluten, so cannot replace all the wheat or rye flour in bread-making but can be
used at about 15% to give a dense bread with a nutty flavour and moist quality.
Texturised soy protein (TSP or TVP) is made from soya flour that is compressed
until the fibres change in structure. It is available to home cooks as a dried,
granular product and in chunk-sized pieces for rehydrating and use as a meat-replacer.
Following the development of methods to produce isolated soya proteins in the
1950s, it is also processed for use as soya protein in biscuits, sweets, diet
drinks, pasta and frozen foods; it also improves the consistency of meat products.
It is added to many foods including pizzas, noodles, bread, foods for special
dietary needs, for instance soya drinks, which serve as a substitute for cows
milk. Various cheese and other milk and meat substitute products, such as miso,
tofu and tempeh, can be made by fermenting soya protein. In addition, naturally-brewed
soya sauce uses a starter culture called koji, a member of the Aspergillus family,
with a mixture of soya beans and wheat.
Soya in nutrition
Soya
bean protein quality is comparable to meat and eggs. The vegetable oil is poly-unsaturated,
has a low level of saturated fatty acids and is free from cholesterol, but contains
both essential fatty acids - linoleic and linolenic. Soya beans and the foods
made from them are also rich in iron, B vitamins, calcium and zinc. Soya protein
is said to have the effect of reducing cholesterol levels in hypercholesteroaemic
people (Anderson, 1995). The Food and Drug Administration (FDA) is proposing to
authorise the use of a health claim for foods which contain soy protein which
will allow them to state that they can reduce the risk of heart disease. The action
comes in response to a petition filed by Protein Technologies Inc (PTI), a leading
supplier of soy proteins and a unit of DuPont. If such as claim is allowed soy
will join oats as a food allowed to claim on packaging and labels that it "may
reduce the risk of heart disease, as part of a diet low in saturated fat and cholesterol".
Foods that would be able to carry the claim include soy milk, vegetable burgers
and tofu (New Nutrition Business, 4(3), 1999).
Soya and phytoestrogens
Soya is an important source of a group of non-nutrients known as the phytoestrogens;
compounds with structural and functional similarities to the natural oestrogenic
hormones present in the body. Examples are daidzein and genistein, present at
levels around 3mg/100g wet weight in raw beans. In certain situations these chemicals
can behave like a very weak form of oestrogen.
Epidemiological studies (primarily
from Japan, where soya consumption is high) suggest a beneficial, protective effect
for the phytoestrogens against certain sex hormone-dependent cancers - including
breast and prostate cancers. Phytoestrogens present in a wide range of food plants
(including soya) may have deleterious effects on reproductive efficiency when
consumed by animals; there is no evidence for a parallel effect in man. Work is
under way which will give a better understanding of how the phytoestrogens in
soya behave in humans, since these actions are complex and not completely understood.
Babies may be given soya-based formula milks for one of the following reasons:
(1) a small number of babies cannot tolerate cows' milk; (2) some parents choose
for themselves to feed their baby soya-based formulae because they have a family
history of allergy or for other reasons; (3) soya-based formulae are made entirely
from plants and this makes them acceptable to vegans and other groups who do not
want to use feeds based on cows' milk. At present there is no evidence that phytoestrogens
in soya-based formulae cause any problems.
The UK's Chief Medical Officer
recommends that 'if your baby is under one year of age and your doctor has recommended
that you feed your baby with a soya-based infant formula, you should continue
to do so. If your baby is over one year of age, you should ask your doctor or
health care professional about introducing your baby to cows' milk as babies can
outgrow allergies. If you are using a soya-based formula, but not on the advice
of your doctor or another health care professional, talk to your doctor or other
health care professional about whether to continue using it or whether to switch
to another type of feed'.
Genetically-engineered soya - the technology
Monsanto, the US-based multinational speciality chemical and pharmaceutical company,
has developed a new soya bean plant which is genetically-engineered to be resistant
to the Monsanto herbicide, Roundup.. In traditional soya varieties, Roundup.
blocks the build-up of essential substances for growth of the soya plant, but
the modified plant, Roundup ReadyTM produces a new type of protein enabling it
to circumvent this blocker. One of the claimed advantages of using Roundup ReadyTM
soya beans is that weeds can be controlled after the young beans have started
to grow, with just one herbicide. Monsanto estimate that around one third less
herbicide overall can be used with this variety compared with conventional crops.
Monsanto say that genetically-modified (GM) soya is indistinguishable from conventional
beans in composition, nutrition and processing characteristics; a US company Genetic
ID claims to have a test available that can detect the genetic alteration, but
this method will only work prior to processing. The new protein is not found in
soya oil or lecithin and it is claimed that protein traces in soya meal are inactivated
during processing. People who are allergic to conventional soya products will
also be allergic to the genetically-modified soya products.
Genetically-engineered
soya - regulation
Oversight of this technology and other genetic modification
techniques is provided by the US Department of Agriculture, the Food & Drug
Administration and the Environmental Protection Agency. FDA ensures the safety
of foods developed by genetic engineering through science-based risk evaluations.
This requires developers of foods from modified plants to address whether known
allergens have been transferred to the modified product; to demonstrate that the
new food does not contain increased levels of previously-known toxic substances
or new hazardous substances; and that the nutritional value of the product has
not been compromised.
The final US approval for use of Roundup. herbicide
with herbicide-tolerant soya beans was granted in Spring 1995 by the US Environmental
Protection Agency. The EU authorities issued an import licence according to EC
directive 90/220 (product release directive) in Spring 1996 - although this approval
is restricted to import and processing. It is also approved as safe by Japan,
Argentina and Mexico.
Genetically-engineered soya - production, processing
and labelling
The 1996 USA crop of 64 million tonnes contained about 2%
of GM soya beans. The 1997 crop contained approximately 15% GM beans. Monsanto
says that segregating beans for mass markets would be economically and physically
impractical for farmers, grain companies and shippers. The arrival of deliveries
of mixed GM and traditional soya beans in Europe (9Mt out of a total European
market of 13-14Mt) has resulted in widespread discussion over the safety and labelling
of genetically-engineered ingredients in foods.
The UK's Advisory Committee
on Novel Foods and Processes stated in 1994 that "the Roundup ReadyTM soya beans
...and products derived from these beans are equivalent to and as safe for human
consumption as beans from conventional soya bean strains and products derived
from them." At a UK press conference in August 1996, ACNFP Chairman Professor
Derek Burke said:- "The beans are processed by a severe extraction procedures
that destroy the plants' genetic material and also destroy the bacterial enzyme
introduced to make it resistant... In the products there is no bacterial DNA or
bacterial enzyme. Flour from the new soya is analytically indistinguishable from
the traditional soya."
The USA's Institute of Food Technologists comments
that 'food labels have been established to provide "material information" about
a product, such as ingredients and nutrition information, or warnings about a
health risk. Since genetically-modified foods do not pose any new or unique risks,
such labels would not provide health or safety information and could mislead by
implying that there is a risk'.
Commodity crops such as soya are traded on
the international markets in huge amounts. Segregating of commodity crops requires
separate production and handling facilities at every stage of the supply chain.
The UK bread-baking industry has bought some supplies of 'identity-preserved'
conventional soya from Canada, and the frozen-food supermarket chain Iceland is
among many UK retailers avoiding the use of genetically-modified soya in their
own-label products.
Agreement has been reached on an EC Regulation (1139/98)
on the labelling of (GM) soya and maize (MAFF Food Safety Information Bulletin,
July 98). This requires all food products containing GM soya ingredients to be
clearly labelled. Declarations will appear in either the ingredients listing,
for example, in relation to soya ingredients as follows: soya flour (produced
from genetically modified soya); or soya (genetically modified) flour; or soya*
flour; then as a footnote, which may be no smaller than the list of ingredients:
* genetically modified; or * produced from genetically modified soya. In the case
of products where there is no ingredients list, the words 'produced from genetically
modified soya' must appear on the product label.
The Regulation came into
effect on 1 September 1998. It will not however apply to products manufactured
and labelled prior to the Regulation coming into force, nor to products in which
neither novel protein nor DNA is present. The Regulation also contained a six
month transition period for products where other forms of wording have been used
to indicate the presence of GM material.
The UK Consumers' Association commented
in the March 1999 edition of 'Which?' magazine that "any food ingredients containing
GM material (protein or DNA) from soya are labelled. But where protein or DNA
from the GM source is removed in the processing, the regulations consider that
these ingredients are equivalent to conventional ones, and so don't have to be
labelled. For example, some oils produced from GM soya, contain no detectable
protein or DNA in the finished product.
Additives produced using GM technology
are also exempt from GM labelling, although this is currently being reviewed and
may change in the future. Currently, there is no list of agreed European ingredients
that don't need labelling so it is up to the manufacturer to decide which ingredients
are exempt. Outside Europe, the international agreements on labelling are still
being debated."
Pressure group and public attitudes to genetic engineering
in the food chain
Some pressure groups oppose all forms of genetic engineering,
but others are either focusing on particular aspects of the technology in plants,
or animals, or on environmental concerns. Some prioritise the issue of consumer
choice - demanding the labelling of foods containing GM ingredients.
Providing
effective communication about the benefits and risks of new technologies depends
on understanding the underlying concerns of the public as well as the more technical
issues. The public's perception of the risks of genetic engineering is mediated
by their recognition of the tangible benefits of specific products of the technology,
for example genetically engineered products with health- or environment-related
benefits.
If information about genetic engineering in the food chain is perceived
by the public as coming from a source that they do not trust, or promoting a particular
vested interest, there is a danger that this could result in an unnecessarily
negative perception of the technology by consumers. It is also useful to address
some of the wider social issues (for example, worries about ethics) in the information
provided, as these might also be driving consumer reactions (see publications
by Dr Lynn Frewer and colleagues for further information).
Consumers around
Europe have recently been questioned on their attitudes to GM foods. Across Europe,
in a 5000-person MORI/Greenpeace poll, 59% were opposed to its development and
22% supported it, with the French and Danish coming out most strongly against.
The British showed some of the most positive attitudes with only 51% opposing
development. A separate survey in Germany found that 95% of consumers wanted mandatory
labelling of these foods.
Some publications in the literature
Anderson,
J. W., Johnson, B. M. & Cook-Newell, M. E. (1995) Meta-analysis of the effects
of soy protein intake on serum lipids. New England Journal of Medicine 333 276-
Burks, A. W. & Fuchs, R. L. (1995) Assessment of endogenous allergens in glyphosate-tolerant
and commercial soybean varieties. Journal of Allergy & Clinical Immunology
96 1008-
Butler, D. (1996) Europe agrees a compromise on food labels. Nature
384 502-3
Frewer, L. J., Howard, C. & Shepherd, R. (1996) Effective communication
about genetic engineering and food. British Food Journal 98 (4/5) 48-51
Frewer,
L. J., Howard, C. & Shepherd, R. (1996) The influence of realistic product
exposure on attitudes towards genetic engineering of foodstuffs. Food Quality
& Preference 7 (1) 61-67
Frewer, L. J. & Shepherd, R. (1995) Ethical
concerns and risk perceptions associated with different applications of genetic
engineering: Interrelationships with the perceived need for regulation of the
technology. Agriculture & Human Values 12 (1) Winter 48 -57
Tuley, L.
(1996) Healthy outlook for soya proteins. IFI no 5 24/5 and 27/8
Items from
Nature magazine
Distrust in genetically altered foods - editorial (1996).
Nature 383 559
Genetic resistance spreads to consumers - news (1996). Nature
383 564
Trade war looms over gene-altered foods - news. (1996). Nature 384
301
Pros and cons of foreign genes in crops - correspondence (1997) Nature
385 290
Further information from:-
Advisory Committee on Novel Foods &
Processes, Ergon House c/o Nobel House, 17 Smith Square, London SW1P 3JR tel.
020 7238 3000 (report on herbicide-tolerant soya beans in 1994 Annual Report)
Biotechnology & Biological Sciences Research Council PR Dept., Polaris House,
North Star Ave, Swindon SN2 1UH tel 01793 413200 (including the booklet 'Ethics,
Morality and Crop Biotechnology' by Roger Straughan and Michael Reiss)
Biotechnology
in our Food Chain - website developed to provide a public information service
on some of the key issues of interest to the public; explores the potential opportunities
and risks associated with food-related biotechnology (http://www-biofuture.cbcu.cam.ac.uk)
European Federation of Biotechnology tel +31 70 3653857 (biotechnology handbook
and leaflets)
Food Advisory Committee, Ergon House c/o Nobel House, 17 Smith
Square, London SW1P 3JR tel. 020 7238 3000 (including Q/A on GM soya beans attached
to press release issued as FAC15/96)
Food & Drink Federation, 6 Catherine
St, London WC2B 5JJ tel. 020 7836 2460 (for a copy of booklets in the 'Food for
our Future - a guide to modern biotechnology' series); web site address: http://www.foodfuture.org.uk
Genetic ID, 500 North Third St Suite 208, Fairfield Iowa, 52556, USA
Genetics
Forum, 94 White Lion St, London N1 9PF tel. 020 7837 9229 (for booklets including
'Spilling the Genes - what we should know about genetically-engineered foods')
Green Alliance tel 020 7836 0341 (for copy of 'Why are environmental groups concerned
about release of genetically modified organisms into the environment?' and other
briefing documents); web site address: http://www.gn.apc.org/gralliance
Greenpeace,
Canonbury Villas, London N1 2PN tel 020 7865 8100 (for a handout entitled 'Health
and Environmental Risks of Genetically Modified Soya' and other briefing information)
Institute of Food Technologists - 221 N LaSalle St, Suite 300, Chicago Il 60601-1291,
USA; tel 001 312 782 8424 and world wide web site at http://www.ift.org/
Institute
of Grocery Distribution, Grange Lane, Letchmore Heath, Watford WD2 8DQ tel. 01923
857141
http://www.foodstandards.gov.uk/industry/soyalist.htm (for lists of
soya bean growers and distributors offering supplies of non GM soya) and for other
information on soya (use the 'search' facility on the site)
Monsanto Europe
S.A./N.V., Avenue de Tervuren 270-272, Tervurenlaan 270-272 Letter Box No 1, B-1150
Brussels tel 00 32 2 776 41 11 (for information packs including 'Plant Biotechnology
- harvesting solutions for tomorrow's world' - produced jointly with the American
Dietetic Association)
National Centre for Biotechnology Education tel 0118
987 3743 and web site http://www.ncbe.reading.ac.uk (for resources for biotechnology
education)
National Farmers Union, 164 Shaftesbury Avenue, London WC2H 8HL
tel. 020 7331 7200 (for information about their Biotechnology Working Party)
National Food Alliance, 5-11 Worship St, London EC2A 2BH tel. 020 7628 2442
The American Soybean Association, Rue du Commerce 20-22 bte 4 1040 Brussels -
Belgium
The Food Commission (UK) Ltd, 3rd Floor, 5/11 Worship St, London EC2A
2BH tel. 020 7628 7774
The Soya Bean Information Centre, 59 Russell Square,
London WC1B 4HJ tel. 0345 023288 (for handouts on soya and access to a 'Careline'
operated by Monsanto)
Compiled and Issued by:
IFR Communications
Institute
of Food Research,
Norwich Research Park
Colney, Norwich NR4 7UA, UK
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