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?