The beauty parade
In the supermarket beauty parade, an apple must look good in front
of the camera or risk rejection. A Dutch firm provides packhouses
with extremely expensive machines, to
measure 'cosmetic perfection'. The 'Greefa Intelligent
Quality
Sorter' takes up to 70 colour pictures of every apple on the
conveyor belt to determine the 'blush of non-equally coloured
fruit', and to grade it by size. It can detect deviations of as
little as 1mm². So if the supermarket specification says that an
apple of a particular variety must be, say, 15-17% blush red on
green, it can 'grade out' or reject any that are 18% red on green
or a miserable 14% red on green.
The beauty parade often means
the
difference between profit and loss for the farmer. Anything
'graded out' ends up, if the farmer is lucky, as fruit for juice
at giveaway prices, but as often as not it will
just go to waste.
Then there's the penetrometer, a spring-loaded tool to measure the
fruit's resistance. 'I had the buyer round and he said my
pressures were out,' says John Dickson. 'He admitted my Coxes were
the best he'd tasted, but they weren't hard enough for his shelf
life. He told me I'd have to pick earlier. No wonder people
complain fruit doesn't taste of anything. They also get tested for
starch and sugars and all that. I test mine the traditional way,
with my front teeth. I can't get very excited about all this.'
It's the same with plums. Dickson grows 32 varieties, can start
picking in July and still have plums at the end of October. But
the supermarket season lasts only a few weeks, and they'll take
only three varieties. 'The market for Victorias used to work
really well. The largest went to the fruit market, the middles to
canning and the smalls for jam. Now the smalls get thrown away and
most of the middles do, too. They've got to be 38mm, unmarked,
with stalk, to pass muster. The specification covers two sides of
A4. The shape must be "typical", they must be more than 50%
coloured, but they've also got to have a four-day shelf life. That
means they've got to be picked rock-hard. Plums need to be picked
and eaten within a day or two to taste good. I can see an enormous
supermarket from my fields. I asked if I could supply it direct
with plums that were ripe, in peak condition. It can't be done.'
Size matters, too. The fruit that survives the penetrometer must
then conform to supermarkets' vital statistics. For Dickson, this
presents its own problems. 'When I was a boy, 60mm was considered
the ideal size for an apple: that would be five or six apples to a
pound; you'd sell 65mm ones for a premium. But 65mm gave you four
apples to a pound. Now supermarkets want a minimum of 70mm from
me, so you only get three to a pound. Which means most customers
end up buying more: to get four apples now, you need
one-and-a-quarter pounds.
'But to achieve bigger apples, I have to prune my trees much
harder, and overfeed them. The apple is less well balanced because
of excess fertiliser; it loses its flavour. Then you get bitter
pit [brown spots] and I have to spray with calcium to prevent
markings.' A Cox may have been sprayed up to 16 times by the time
it reaches the shops.
Washed and ready-to-eat salad
In an idle moment, I decided to reconstruct the contents of a
bag of washed and ready-to-eat salad. Of course, you are not meant
to do this, the whole point of bagged salad being that we are too
busy to wash our own lettuce leaves, let alone count them. But I
wanted to know how many you get for your money. Erring well on the
side of generosity, I reckoned that for roughly 2 euro I had bought
two leaves of frisée, one leaf of red radicchio and two leaves of
a pale green, crunchy variety of lettuce. This portion was livened
up by 18 tiny whole leaves and seven torn pieces of dark green
leaves about the size of a 10 cents coin.
Bagged salads did not exist before 1992. Now, two-thirds of
households buy them regularly. The value of the salad vegetable
market had, in fact, grown by 90% between 1992 and 2002.
This does not mean we are eating 90% more salad - volumes have
grown only by 18% over the same period - just that the food
industry has found ways to make much more money out of salad.
Thanks to global sourcing and advances in packaging technology, we
have got used to the idea of eating a variety of salads all year
round. Modified-atmosphere packaging (Map) can increase the shelf
life of prepared salad by over 50%, making it possible for
supermarkets to sell washed and bagged salad from around the
world. Lettuce and salad leaves are harvested from fields in the
UK, southern Europe or the US one day and reach a packing house
either the same day or a day or two later if imported. The salad
is cut or separated into individual leaves by gangs of workers,
then washed in chlorine, dried and sorted, before being packaged
in pillows of plastic in which the normal levels of oxygen and
carbon dioxide have been altered. This slows any visible
deterioration or discolouring. The salad is then trucked to a
distribution centre where it will be dispatched for delivery to
the stores. Map keeps it looking fresh for up to 10 days. Some
lettuces imported from the US are kept fresh in Map for up to a
month.
Unfortunately, some research published in 2003 in the British
Journal of Nutrition suggested that this new invention to prolong
shelf life and provide us with convenience while multiplying
profits might actually destroy many of the vital nutrients in
salad.
A team of researchers and volunteers at the Rome Institute of Food
and Nutrition had conducted an experiment. They took lettuce grown
by a cooperative and gave it to volunteers to eat on the day it
was harvested; lettuce from the same source was then given to
volunteers to eat after it had been packed in Map and stored for
three days. Blood samples of the two groups were analysed after
they had eaten the salad. The researchers noted that several
anti-oxidant nutrients - which protect against ageing,
degenerative disease and cancer - such as vitamins C and E,
polyphenols and other micronutrients, seemed to be lost in the Map
process. The volunteers who had eaten the fresh lettuce showed an
increase in antioxidant levels in their blood, but those who had
eaten lettuce stored for three days in Map showed no increase. The
researchers noted that nutrient levels fell at a similar rate in
lettuce stored in normal atmospheric conditions, the difference
being that a lettuce stored normally showed signs of limpness
after a few days, whereas with Map the illusion of freshness is
preserved.
When the results of this trial were published, they provoked a
defensive debate among packers. Jon Fielder, director of
a company called Waterwise, which sells ozone-based disinfecting
systems to salad packers, wrote to the trade magazine the Grocer:
"It is commonly acknowledged that Map does have an effect on the
depletion of nutritional value of salad, however it is the
chlorine used by most packaged salad producers in the washing
process which has a far worse effect on consumer health. In most
cases, the salad leaves are immersed in water with chlorine which
is an oxidising disinfectant. The chlorine level is usually
maintained at a minimum of 50mg per litre - 20 times higher than
in the average swimming pool." In fact, the Italian researchers
had not used chlorine, so the Map must have been responsible for
the nutrient loss, but it was a helpful addition to public
knowledge to have the industry view on chlorine washes.
Chlorine washes leave surface residues of chlorinated compounds on
lettuce, and because of this the process is banned in organic
production. Some chlorinated compounds are known to be
cancer-causing, but there appears to be little research on those
left on foods treated with high doses of chlorine.
"As well as disinfecting out the bugs, they disinfect out the
taste of fresh leaves, as anyone who has eaten salad straight from
the garden knows," Fielder points out. But controlling bugs is all
important. As Fielder says, "In a litigious society, and with the
prospect of damage from bad publicity, no supermarket dare risk
having E coli food-poisoning bugs on the salad they sell."
There appears to be good reason for supermarkets selling prewashed
salads to worry. Between 1992 and 2000, the period in which bagged
salads took off, nearly 6% of food-poisoning outbreaks were
associated with ready-to-eat salads and prepared fruit and
vegetables. In 2000, two serious outbreaks of salmonella poisoning
were traced back to lettuce.
Once the market started growing so rapidly, the government
decided to monitor
bacteria levels in salads. A study of refrigerated ready-to-eat
salads sold at retail stores in 1995 found that 6.5%
contained listeria and 13% E coli bacteria. The most recent
survey in 2001 found salmonella in five samples and high levels of
listeria in one sample of ready-to-eat salad from three major
supermarkets. One of the samples containing salmonella also
contained E coli bacteria. Fuller investigation subsequently
uncovered an outbreak of salmonella poisoning caused by the salad. The majority of the
samples were fine, but, as the authors of the study pointed out,
the new methods of packing raised new dangers.
Effective decontamination of ready-to-eat vegetables is difficult.
E coli bugs are usually spread from human or animal faeces, either
from the unwashed hands of farm or packhouse labourers, from
manure that has not been properly composted, or from contaminated
water. Good hygiene practices are essential to controlling them.
But Fielder, even as someone who sells disinfecting technology,
says, "The longer the factory chain, the harder it is to control
contamination. I always feel I should wash the lettuce I buy, even
if it is bagged and 'ready to eat'."
Anyone for a good quick salad?