MFCM096: Food Irradiation - The New Toy?.pdf
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COMMUNITY Hi.7U.Th C
7/L (First Floor)St. Marks Hoad
BANGALORE- 560 001
food irradiation
THE new toy ?
- By A.T. Dudani
Although food irradiation has been in use in U.S.A, for almost
30 years it has not caught up largely on account of the now
well known,small but crucial Delaney Amendment in 1958 to the
Food,Drugs and Cosmetic Act which described food irradiation
as an "additive" instead of a’ "Process" . This puts tb,e onus
of proving
safety of any additives squarely on the manufacturers.
The rationale being that irradiation resulted in new molecules
in food that were not present before. To date some 30 countries
have permitted commercial irradiation of 28 different food items.
World-wide annual capacity of food irradiation is about 4.724
lakh tonnes-bulk of which is being used for wheat (4 lakh tonnes)
and the balance for spices,fruits,and vegetables and seafoods.
Canada has so far sold some 134 Food Irradiatiors world-wide,
including 4 to Inaia largely for use in sterlisation of .medical
products. However in 1979, India exported one Irradiator to
Indonesia,’This country is endeavouring to enter food irradiation
in a big way and some 5 Food Irradiators are at present in the
process of fabrication and installation in addition to 4 already
in operation.
How Irradiation Works:
When radiation strikes- other material it transfers energy. At a
certain level this radiation knocks out elections from the atoms
of the material exposed-which in turn breaks the molecular
structure of the material yielding ions or free radicals- hencethe term ionising radiation.The ions being chemically very active^
easily re-combine with surrounding material. These give rise to
potentially’toxic materials products (URPs for short), while many
of the URPs are similar to.those that occur in cooking of food,
sone are unique to irradiation and have been implicated in
causation of cancer. Formation of URPs has been found to be
related to the dose of irradiation used.For example 10 KG
results in about 300 mg of URPs per kg of food. Thus.irradiation
triggers chemical reactions- 1 causing gross disruption of the
DNA in the cells, thereby inhibiting cell growth or division.
Whereas USA permits at present 1 KGy (equivalent of ten million
chest X-Rays) in India dose of upto 10 KGy has been permitted.
Irradiation Process:
This itself is not very complicated. Food is placed on a conveyer
belt which takes it to a chamber and source of ionising irradiationj
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Trot .■.’tive casing is removed enabling rays to go through the food
a nd i ts pac ' :agi ng.
The dosage as also the amount of exposure ranging from several
minutes to several hours is pre-determined.
Radiation doses are expressed in terms of Grays' (Gy) or in rads
(radiation absorbed dose) one Gy equaling .100 rads (1 Kgy equal to
100,000 rads).
--Concern:
There are essentially 4 main areas of concern regarding widespread
use of ionising radiation to sterlise,disinfest or stabilise food.
Firstly the chemical impact of heavy doses on the food itself and
:en§ure that mutagenic or cacinogenic compounds or URPs are not
formed.
.
Secondly whether the food, is reddered safe from 3 poilage microbes
and pathogens like botulinum and that.irradiation does not give
rise to mutants which produce, increased amounts of highly
undesirable products much as aflatoxins i.
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. •.
Third that vitamins and amino acids, minerals are not destroyed.
A new area of concern is the possible deletorians effect of
irradiation on antioxidants and other addict!ves in foods.-
Fourthly that Irradiation plants do not create any threat either
to environment or any undue occupational health hazards by way of
accidents, disposal of waste or transport or radioactive material.
W^at-is,. the_rocord:„
There is irrefutable evidence .that irradiated foods suffer a
significant loss of vitamins A,B,C & E and some essential amino
acids. Depending on dosage, in apples 70% loss of Vit. C has been
reported. In case of wheat flour, 67% of thiamine was lost on
irradiation and 8 months storage as against 25% loss in the non
irradiated control. Likewise in rolled oats the corresponding
loss of
vit. E was 85% and 26% respectively.
In another significant USDA has reported that thiamine content
of bacon in raw cooked or freeze dried from degraded at
significantly higher rate during cooking if the bacon had been
irradiated.
Some, dangers
Studies have also shown that gamma irradiation was
unable to
inhibit botulinal toxin production in frankurters if normal
salt content was reduced.
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Stimulation and rapid division of naturally occuring aflatoxin
producing moulds has also been observed in irradiated foods.
Aflatoxins are 1000 times more carcinogenic than the banned
pesticide Etnyl dibromide for which irradiation has teen suggested
as a possible substitute. That fact that you cannot see it, taste
it, smell it or even test for it, also poses problems of misuse.
Cell for Ban:
It is not therefore surprising that British Medical Association,
and more recently the.European Parliament has called for a ban on
food irradiation. Several scientists, including 2 Nobel Laureates,
Linus Pauling and George Ward have also supported a ban on food
irradiation specially in view of results of trials at National
Institute of Nutrition(NIN) Hyderabad during 1973-75 which showed
polyploiding in blood,which has been linked with cancer. Although
this work was caught up in a fierce controversy, recent evidence
notably from Canada , U.K. and Austrialia supports the results
obtained at 'NIN.Studies from US and Japan Radiation Research
Foundation, Tokyo also show that harmful effects of nuciear
radiation from Atomic bomb 42 years ago had been grossly under
estimated due to a faulty calcuifaiions and US reluctance to
provide information.
Moratorium pending safe.ty_ assu;rancej.
A conference of delegates from 9. Asia-Pacific countries co
sponsored by International Organisation of Consume-r Union,Penang
which met at Canberra 9-11 November, 88 h^as £n. a declaration urged
W.H.O. to re-open the issue and also called for a world-wide
moratorium on further use and development of food irradiation until
various issues were sorted out.. This is considered feasible since
safe alternatives already exist, which can be further developed.
Agency has been created under the Secretary,Ministry of Health,
as Chairman to deal with all matters relating to irradiation of
foodstuffs.
It does seem surprising that while this country faces the imminent
prospect of its irradiated food exports being banned in several
countries and boycotted in others, it is going ahead with building
5 new commercial irradiators ( hopefully not for exports).
(Background Paper for XVI Annual Meet of MFC)
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