The sachets are packed with Plumpy'nut - known to millions of hungry and formerly hungry children as Plumpy - a peanut-butter food for the acutely malnourished which may have transformed the way hungry people are treated. The French newspaper Libération called it "this magic potion".
"That's excessive," says Isabelle Sauguet, the sales and development manager at Nutriset, the French humanitarian foods company that invented Plumpy'nut. "I don't think magic potions exist outside of Astérix. But it has been revolutionary."
The ingredients of this revolution are simple: peanut paste, vegetable oil, milk powder, vitamins and minerals, combined in a foil pouch with red lettering and an apostrophe shaped like a peanut. Cut the corner of the pouch, feed to a severely malnourished child two to three times a day for about 40 days, and the child will usually be up and about. Normally, a quarter of severely malnourished children do not survive, even in clinical conditions. With Plumpy'nut, death rates can be cut by half.
"This isn't a small step," says Dr Mark Manary, an American paediatrician who uses peanut paste to feed the malnourished children of Malawi. "It's a quantum leap."
And it is needed. Every five seconds, a child dies because of hunger. Starvation kills more people than Aids, TB and malaria combined. Severe malnourishment - starvation complicated by disease - is a condition as easy to get as it is tricky to treat. The World Food Programme usually treats malnourished adults with one and a half cups of rice or flour, a tablespoon of beans or lentils, a spoonful of oil and salt. But the more vulnerable severely malnourished - women and children - have to be given high-energy milk formulas called F100 and F75 that took years of research to develop.
Ideally, a malnourished child stays in a therapeutic feeding centre, or TFC, for up to four weeks, being fed at two- or three-hourly intervals, with milk formulas carefully diluted and measured according to the child's weight. If all goes well, the child should recover in about a month. The treatment is labour-intensive, requiring strict protocols, careful dilution and clinical supervision, but there is no doubt it works. That wasn't the problem.
"We were already asking ourselves questions about TFCs," Caroline Wilkinson, a nutritionist with Action Against Hunger, says. "We were asking ourselves whether mothers could and should stay for such a long time in a TFC, because it has consequences on life at home."
Every child in a TFC must be accompanied by a carer, usually the mother. This takes the mother away from other children she might have, and from her fields.Dr Steve Collins, of the NGO Valid International, says feeding a child in a TFC "has a negative impact on food security. It's a nasty cycle".
Malnutrition damages the immune system, so putting sick children among sick children is perfect breeding ground for infection. Dr Collins says: "The impetus really came in 1998 in southern Sudan. There were tens of thousands of kids crowding centres that only had space for hundreds. It was obvious we had to find another way."
The solution, some believed, was to treat the child at home, but with what? The milks had to be carefully diluted with clean water. When the mother is illiterate, and the water is dirty, it is not going to work. Even leaving the milk standing can contaminate it, because bacteria grows in water. Anything else had to be non-water-based, easy to store, easy to feed and easy to eat. It had to be a ready-to-use therapeutic food, or RUTF, that did not require clinical supervision.
Then Andre Briend, a child nutrition expert, saw a jar of Nutella. For a while, he had been looking for a viable alternative to high-energy milk. Paste was it, he realised, and contacted Michel Lascanne, the CEO of Nutriset, who was on a similar quest. M. Lascanne had developed a chocolate bar during his time at a French dairy company, but the taste was bad, and in high temperatures, the chocolate melted. A paste made of peanut butter would store easily, M. Lascanne and M. Briend realised, and it was rich in protein and energy.
By 1999, the recipe was ready. It just needed a name. "We didn't want a scientific name," Mme Sauguet says. "We wanted an English name because so many people in the field work in English. We started with pump, then plump, then Plumpy'nut. We wanted something that encapsulated joie de vivre. A little bit of happiness."
And a lot of business. Now, the 40-strong staff of Nutriset, in their factory near Rouen in northern France, make a product that saves the lives of hundreds of thousands of children. "We're not replacing NGOs," Mme Sauguet says. "We just hope we've taken on the cooking that they were having to do to prepare the milk. If the humanitarian network is a restaurant, we're in the kitchen, out of sight."
Since January this year, Nutriset's 24-hour production line has produced 1,300 tons of Plumpy'nut, which sells for 18p a sachet. It is not much cheaper than the milks, but the sachets take up less transport space, and NGOs save on the cost of hospital treatment. Mme Sauguet says: "Plumpy'nut is complete and it's clean. A child can feed himself, but he will self-regulate."
Saskia ven der Kam, a nutritionist with Médecins Sans Frontiéres Holland, says: "It's hard to overfeed with Plumpy'nut. It's easy to gulp down milk but it takes hours to eat a jar of peanut butter." And it even tastes good, thanks to the 28 per cent sugar content.
But why did something so simple take so long to be invented? After all, the nutritional properties of peanut butter have been known since the freed-slave agronomist George Carver Washington invented a way to use surplus peanuts in the 19th century. Dr Collins says: "Partly, it's because the milks were so good. But also, it's because the treatment of severe malnutrition has been over-medicalised. Doctors see a severely malnourished child and they say, 'There are metabolic complications, you have to put them in hospital'. That's not always true."
Dr Collins is the best-known advocate of CTC, or community-based therapeutic care, which means children are treated at home after an initial triage and treatment phase. It needs ready-to-use foods to work, but Dr Collins says the revolution is not about one brand. "Plumpy'nut has a good name," he says. "But writing about it is like writing about dental hygiene and talking only about Maclean's toothpaste. It's not just about the product, it's about the delivery. If every time someone is malnourished you put them in hospital, you're giving the message that the family can't deal with it."
In fact, mothers can treat even a severely malnourished child, with the right food. In Malawi, Dr Manary came to a similar conclusion about home-based treatment. "I was working in the hospital in 1994, and they told me, 'Don't go to the malnutrition ward'. So I went. And it was an icky, awful place. I realised the kids weren't recovering. It was 15 per cent recovery, 20 per cent relapse and 40 per cent malnourished and the rest died. Obviously, that was unsatisfactory."
Dr Manary researched RUTFs, and used them. With a mixture of traditional foods and RUTFs, 75 per cent of children recovered. On an entirely RUTF diet, recovery was 95 per cent. "Usually something that works on a small scale doesn't work on a big scale. But this did."
In 2003, he began thinking about how to deliver the food cheaply and appropriately, and Project Peanut Butter began. They used local food - peanut butter, chickpeas or soya - and added the milk, oil and vitamins. They tested recipes on the two children of the local MSF director, and found one that worked. Dr Manary says: "It has everything it needs in it. Nobody has to cook it, which was one of the barriers. The kid just has to stick his finger in the jar. There's no water, so bacteria can't grow. And third, it's not like any other food people eat - we tell them it's 'special medicine food' - so there's less problem with sharing [with siblings]." Nutriset had no objections. The doctor says: "They heard about what we were doing and they were like, 'that's neat'. They've been an ally and a friend." A Nutriset food scientist helped set up the Project Peanut Butter factory, and a Malawian production manager did a two-week internship in France. Mme Sauguet says: "Our philosophy is to feed children. As long as it's for a specifically humanitarian aim, and the quality control is acceptable, that's fine."
It is less fine if the rival is a commercial company. Nutriset's M. Lascanne says profits - which have doubled since 2001 - are put back into research and development, and the company has so far refused to countenance using its technology to sell purely commercial products such as high-energy bars for athletes. But when the German company MSI - like Nutriset, a for-profit manufacturer of humanitarian food products - tried to develop its own version of Plumpy'nut, "We ran into big problems", its CEO, Dietmar Kneer, says. "We didn't know there was a patent on the product and we got into trouble with Nutriset. They've built up a monopoly."
Is that not reasonable, for a commercial company? "It seems to me very aggressive, for a humanitarian product. A monopoly makes it more expensive for humanitarian organisations." For now, Plumpy'nut's only real competition is BP100, an RUTF biscuit produced by the Norwegian company, Compact. Patent issues do not concern children such as Milika. When she arrived in Dr Manary's malnutrition ward, she was 18 months old and weighed 5kg. Her grandmother lived on the streets and her young mother had gone back to school. Milika's grandmother fed her the peanut butter, and came back for more when she was supposed to. Milika thrived and survived. HIV-positive children show similar results.
In November, the World Health Organisation, the conservative arbiter of the world's health standards, will consider recommending CTC and ready-to-use therapeutic foods.
If it is not a revolution, then it is a highly satisfactory evolution. "Successful treatment of severe malnutrition was possible before," Ms Wilkinson of Action Against Hunger says. "It will continue to be so without RUTF. But it is a revolution in that it offers a chance to do treatment at home that is safe. It opens a lot of doors that weren't open before."