|
|
Choose a category:
|
| |
|
Safety |
| |
|
I have a long question about GM food!
What's the real reason for uncertainty about GM (genetically modified) food? What do scientists really think the risks are? Is it to do with potential health risks to humans (and if so is there any evidence that this is a real threat); or is it more to do with not knowing what the long-term effects on the environment/ecosystems will be (e.g. pest-resistant crops might lead to a reduction in the populations of pests, which might mean less food for certain species of birds, which might mean... etc etc)? Or is it really just about people having an instinctive feeling that ‘meddling with nature is bad’?
Secondly, what is the UK's position on GM food in the UK? Is there any distinction between (a) GM crops (b) GM animals and (c) animals fed on GM crops? If not, should there be such a distinction?
Thirdly, what is the UK's position on GM food in developing countries? I'm curious to know whether it's not considered safe for consumers in the UK, while simultaneously being encouraged in developing countries (e.g. which tend to be subject to drought and subsequent famine).
Fourthly, are we already eating GM foods without being aware of it? I've heard in the past that pretty much all the corn (maize) and soya available now is GM... is this true, and if so are there other food products that are basically only available in their new-and-improved GM form now? |
1) The issue of GM is one where the concept of zero risk has enabled the objectors to seize the moral high ground. Scientists will of course, not say there is zero risk, and the objectors have been able to play on a variety of potential negatives such as you mention - particularly with the longer term ones, knowing the scientists cannot say there is no risk. Whilst accurate, this does not help the consumer make an informed decision. It is like trying to prove a negative.
| The idea of animals eating GM food is a grey area |
In addition, the companies developing the GM items have been slow off the mark to demonstrate the advantages to the general public, rather than advantages to the farmer or the pesticide companies. If you ask the public their feelings about GM, there is certainly a feeling ‘meddling with nature is bad’.
2) UK position on GM food - there are definite differences:
- GM crops - not liked but people aware that they exist and are being used.
- GM animals - definitely not liked - as too close to humans, is seen as playing God.
- Animals eating GM - bit of a grey area. Some retailers are seeking to claim an advantage for it, but not widespread.
3) Developing Countries: This goes back to what is the advantage and who gets it? GM technology needs to show clearly defined benefit for the people.
4) GM - are we already eating it? I do not believe that to be true - yet - although within next 3-5 years then it will become likely for certain products or ingredients. Is the consumer ready for this? I am not sure. |
|
|
| I understand that scientists have introduced fish genes into strawberries because the antifreeze component in fish blood is beneficial in preventing early frost damage. Has any of this GM crop ever reached the wild? |
|
This was a new one for us – but we have found some information on the Cornell University website for you. You will see the article starts on the slightly more palatable combination of fish and tomato genes, before moving on to strawberries.
Despite its finding ‘There are no published studies involving strawberries, no companies which have announced research or marketing plans for such a product, no government records of field testing such a plant, and no trace in the media to explain how this story may have originated,’ it does feature a charming picture of a ‘fishberry’. |
|
|
| Is it safe to swallow chewing gum? |
While I wouldn’t recommend it as a regular habit, the general view is that it is not harmful. Chewing gum contains familiar ingredients like sweeteners, sugar syrups and flavours. All of these will dissolve in the mouth as the gum is chewed. The ingredient that gives chewing gum its chewy properties is called gum base. This doesn’t dissolve in the mouth and it will not be digested by the body if swallowed. It will pass through the body and be excreted, in a similar way to fibre. |
|
|
| The threat of bird flu seems to have dropped out of the headlines. Is there any danger in eating poultry or eggs in the UK? And if it's safe here, what about in south east Asia? |
|
All I can do is refer you to the advice given by the UK Food Standards Agency and EFSA (European Food Safety Authority) and many other agencies around the world, which states that avian flu does not pose a food safety risk for UK consumers.
In Asia, the main risk is for those in contact with live poultry that have the disease. |
| |
| How long should you keep food in the freezer for? |
|
From a food safety point of view there is no time limit on the storage of food in a freezer that operates at -18 degrees Celsius. This is because harmful microorganisms are unable to grow at freezer operating temperatures.
Recommended storage times in freezers are for quality only as the eating quality of the food will deteriorate over time, even though it will remain safe. |
|
|
| What
temperature should my fridge and freezer be kept
at, to keep my food safe in the summer? |
 Your
freezer should be at -18°C and the temperature
of the food in the fridge should be at 8°C.
Keep the air temperature in your fridge between
1° and 4°C and your food should be safe
provided you eat it within date. |
| |
| What
kind of food is most likely to cause food poisoning? |
| Bacteria
(germs) love moist food containing protein e.g.
meat, fish, eggs and milk. Any of these foods
eaten without further treatment e.g. sandwiches,
are called high risk food and are a main cause
of food poisoning. Undercooked burgers and chicken
can also cause food poisoning as the bacteria
(germs) will not have been killed. |
|
|
|
Where should
foods be stored in the refrigerator? Ie which
shelves for dairy, cooked meat, raw meat, and
vegetables? |
| Domestic
refrigerators are not really designed to store
food correctly. As a rule raw food go at the bottom
and cooked foods at the top, with salad and vegetables
in the containers provided at the bottom. The
important thing is to prevent cross-contamination
of food poisoning bacteria from raw foods to cooked.
Therefore, wherever possible, food should be stored
in sealed containers. |
|
|
|
Should duck
be cooked to an internal temperature less than
70°C as per the requirements for poultry?
It is common practice to have duck pink and
bloody in the middle - but is it associated
with salmonella? |
| The
practice of serving duck pink in the middle is
traditional practice in restaurants, and yes there
is a potential risk of salmonella. It is suggested
that if the duck is not pierced by a knife or
similar object then bacteria have not been introduced
to the duck breast. This is similar to rare or
blue steaks. However, to be safe, cook your ducks
thoroughly. |
|
|
|
What chemicals
are used in the preparation of washed and 'ready
to eat' lettuce? Do significant amounts of these
chemicals remain on the lettuce, and are they
harmful? |
|
 The
biggest cause for concern is probably that of
pesticide residues left over from the cultivation
of the lettuce itself. Lettuce is quite a demanding
crop and therefore to grow it all the year round,
especially in the UK with our often damp and
grey climate, the growers will use pesticides/fungicides
to increase their rate of success.
The UK's Dept of Environment, Food and Rural
Affairs (DEFRA) has a monitoring programme that
samples and takes action against growers who
exceed the MRL (max recommended limit) or who
are found to use non-approved pesticides. Historically
the residues found have been of inorganic bromide,
particularly in winter lettuce, originating
from the use of methyl bromide, this chemical
is however in the process of being phased out
(because of its ozone depleting properties)
and should be less of a concern moving forward.
I'm not a toxicologist, so for more information
I would suggest looking at the
DEFRA website.
Once the lettuce is harvested it is washed
in chlorinated water, the levels of chlorination
being typically higher than used for drinking
water - but not swimming pool strength! The
leaves are then gently spun dry and any chlorine
left should wash off quite quickly. Some concerns
have been expressed about chloramines, which
form due to reaction of the cut sap from the
lettuce and the chlorine. These are more stable
compounds, and in fact mono-chloramine is routinely
added to our tap water, as it has less of a
taste than regular chlorine treatment. However
in lettuce washing another chloramine - nitrogen
trichloride has been found which in very much
higher concentrations is known to have some
irritancy effects. |
| |
|
I would like
to know the facts on the 2005 Sudan I scare |
 These
links will help you:
|
|
|
|
Is there any
problem in re-freezing frozen products that
have partially defrosted? |
| It
all depends upon the product and what you mean
by partially-defrosted. If the product is raw
and going to be cooked, there is no problem, as
cooking kills bacteria. If it is a high risk food
e.g. cooked chicken, any bacteria which may be
present, will start to multiply during the defrosting
process and the food becomes unsafe to eat. |
| |
|
Is it true
that organic foods contain higher levels of
fungal aflatoxins than conventional foods? |
| There
is no reason why this should be true. Aspergillus
species which produce aflatoxins are fungi which
grow on warm damp materials. Usually found on
ground nuts. which are left to get wet after harvest.
It may be that systemic fungicides would prevent
development during cultivation, but I am not aware
of tests on harvested nuts showing differential
levels of aflatoxins. |
| |
|
Before expiry
and 'best before' dates came in, we used food
(jam, bread, cheese for instance) until it was
visibly mouldy or smelled bad. Did this do us
any harm? |
| I
cannot comment on whether more people were ill
when shelf-life dates did not exist. However a
number of moulds can produce mycotoxins, which
can make people very ill and penicillin mould
sometimes found on jam can cause an allergic response
in some individuals. |
|
|
|
I heard a report
recently that said we are wasting too much money
throwing away food, because of the sell-by date.
They said it was alright to eat fruit
and veg if you cut away the bad bits, and as
long as meat is cooked thoroughly, it can be
used after the sell-by date. Also that tinned
food can be used years after the sell-by date
had passed, as long as the tin wasn't rusted,
dented or pierced.
I was always told this as a child,
and then dates started appearing on tinned produce.
Would you like to comment? |
 All
foods are required by law to have a shelf-life
date. This may be best-before date or use-by date.
Shelf-life dates are based on safety and quality.
A product may remain safe but not of the quality
expected e.g. live yogurt kept correctly will
deteriorate in quality due to enzyme action although
it is still safe to eat. Many products are still
safe and of a reasonable quality after their shelf-life
date but the manufacturers cannot assume the public
will store food safely, therefore they err on
the side of caution. |
| |
|
How many times
can I reheat a meat-based meal? E.g. if I make
a batch of chilli on day 1, reheat on day 2
but do not eat it all, can I reheat it again
on day 3, 4 etc ? |
| Reheating foods
is never a good idea, as apart from the safety
issues you also lose food value. Regarding your
chilli, heating and cooling must be controlled.
The preparation and cooking of the chilli must
ensure the product is safe, i.e. reach 75°C
or above. Boiling achieves 100°C and is best.
The chilli should be cooled as quickly as possible,
and stored correctly at less than 8°C. The
first re-heating of the product should reach the
original cooking temperature, i.e. boiling point.
In theory you can repeat this process, but with
careful management to ensure that no spore-forming
bacteria fill the food full of toxins between
each re-heating process. |
|
|
|
Many thanks to everyone for
their interesting and thought-provoking questions.
We hope to be running similar initiatives
to Ask a Food Scientist in the future.
If you have any comments
or suggestions, please contact our Communications
Team at E:
communications@soci.org
Supported by the Royal
Institute of Public Health |
