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quinta-feira, 5 de dezembro de 2013

Die Rolle der Nanotechnologie in der Welternährung

Die Herausforderung ist gross – bis 2050 müssen weltweit 2 Mrd. Leute mehr ernährt werden als heute. Um die Nahrungsmittelproduktion steigern zu können, sind verschiedene Technologien gefragt. Nanotechnologie könnte eine davon sein – sie könnte dazu verwendet werden, mehr Nahrungsmittel bei kleinerem Wasser- und Düngerverbrauch sowie geringeren Umweltauswirkungen zu produzieren.
The challenge is clear: globally, we will need to feed two billion extra people by 2050. As politicians, industry and scientists turn their attention to the problem of world food security, many believe we will need to use every available tool to tackle this impending crisis. One such tool could be nanotechnology, the applications of which could potentially help us to produce more food, using less water and fertiliser, and with less of an impact on the environment.
A recent Guardian seminar, sponsored by the European Commission, met to debate how we will continue to feed the world, and the panellists – Terry Jones, Kathy Groves and Ian Illuminato, chaired by Alok Jha – considered how important nanotechnology is likely to be in this task. Their opinions were listened to by members of an invited public audience, who were also able to put questions to the panel.
"The scale of the challenge is reasonably well known," suggested Jones, director of communications at trade association the Food and Drink Federation. "The more pressing number, I think, is the eight billion people on the planet by 2025. If we're going to feed them, then we need to produce more food, from fewer resources, with a smaller impact on the environment – and that's going to require us to think differently."
Futuristic goals
Nanotechnology is the engineering of the very small, at the scale of millionths of a millimetre. It can describe both the futuristic goals of building tiny molecular machines and the more contemporary practice of adding nanoparticle substances to consumer products to make them lighter, stronger or more hygienic.
The current use of nanotechnology in the food industry is still in its early stages and generally builds upon longstanding processes and practices in food production. Jones, however, says it is clear that nanotechnology might provide solutions to a range of industry problems.
"You could see nanotechnology used in the cultivation, production, processing or packaging of food," he said. "It could be used to develop new food products or, indeed, improve existing ones."
As well as reducing water use and contamination in food processing, Jones believes nanotechnology could help make food healthier. "In the UK, we talk a lot about what we need to take out of food, but nanotech could help us to add or enable the release of positive foods as well," said Jones, who noted that 30% of food waste occurs in the home and suggested that nanotech-enhanced packaging might tackle this. He also posited that nanotech could be used to enhance our enjoyment of food by providing us with new textures, tastes and colours.
These ideas sound ambitious and all-encompassing, but, in reality, the current use of nanotechnology in food production is limited. An often-cited contemporary example is nanosalt, smaller grains of salt that provide better coverage of a plate of chips while reducing the overall amount of salt used. So far, however, it has been slow to catch on.
The slow uptake of nanotechnology in food might, in part, be down to people's reluctance to see technology tampering with what they eat.
According to Groves, a food microscopist at Leatherhead Food Research, consumers tend not to realise the extent to which science and technology is already used in the manufacture of their food, and have concerns about the safety, overprocessing and "mucking about" with of what they eat. "People do get worried about [nanosalt]," she said, "but it isn't an issue because it's exactly the same in your body as normal salt."
Groves explained that the public are more willing to accept new technologies as medical treatments than in their foods. "If using nanotechnology or other technologies in drug research will help them combat cancer, say, people say yes. They're all for that because the choice is to take the new drug or suffer severe consequences." According to Groves, people just do not see the same issues for food.

Good regulation

This reluctance to accept nanotechnological tinkering in the food industry is shared by Illuminato, of campaign group Friends of the Earth. He believes that many questions about nanotechnology remain to be answered and, until they have been, it is sensible to be cautious.
"Nanoparticles can be more chemically reactive, they can have greater access to our bodies than larger particles, and when they become more bio-available there's a question of whether that also introduces new toxicity risks," said Illuminato.
He is concerned that, because of their extremely small size, nanoparticles might interfere with DNA or be able to cross the human placenta and blood-brain barriers. "I'm not somebody who thinks technology is malicious – I think it's humans that put that on to the technology," said Illuminato. "It's how we manage these things that's going to be important."
When it comes to using nanotechnology and nanoparticles in the food industry, there was a relatively clear consensus among the panel that good regulation will be crucial. "I'm increasingly beginning to view regulation of the UK and EU food industry as positive," said Jones. "But it has to be smart regulation – it has to enable new technology."
Jones believes these regulations need to be risk-based – focusing on the likelihood of a substance to cause harm and the potential severity of this – but that he has seen many cases in which regulation of the food industry has instead taken a hazard-based approach. This looks only at the potential for a substance to be dangerous, without taking into account the likelihood or scale of such danger.
While regulation is clearly necessary, it seems that, right now, there are not that many nano-enhanced foods to regulate. The discussion struggled to come up with many other cases of contemporary nanotechnological food science beyond nanosalt. One of the few other examples is the use of nano-sized encapsulation and/or emulsification techniques for adding vitamins and flavourings to processed foods.
This does not mean the food industry is short on ideas for the future. It is still early days, but Jones suggested the sky is the limit: "You could use this technology to give you the same eating experience from [a favourite food], but with reduced fat or salt." He said nanotechnology was not about making broccoli taste like hamburgers, but about altering processed foods to be healthier without losing their texture or taste.
Audience member Hilary Sutcliffe, director of the Matter think tank on responsible innovation, was keen to emphasise the limits of nanotechnology in food. "If we're really lucky, we might get nanosalt and a couple of nano-encapsulated vitamins that go in products," she told the panel, describing her disappointment in the progress of nanotechnology in food to date.
Sutcliffe explained that these limited applications are expensive and not that useful: manufacturers would rather just reduce salt content than pay for nanosalt, and vitamins and flavourings do not need to be nano-encapsulated because they can be added to foods at the microscale, rather than at the nano-level, which is one thousand times smaller.
She also suggested that, so far, the possible uses of nanotechnology have only been in Western diets and that people should be realistic about its use for tackling the impending global food crisis. "Nothing about nanotechnology is in relation to anything except Western, expensive foods that are slightly gratuitous and not particularly necessary," she said, before adding that it is not currently helping to feed the world. "If you are going to talk about feeding the world, be brave, take on GM, let's have that discussion."

Genetic modification

It is difficult to talk about the role of technology in increasing the intensification and sustainability of agriculture without discussing genetic modification.
Jones includes GM in his hypothetical toolbox for tackling food security, alongside boosting traditional plant-breeding programmes. "I think all parts of the supply chain [need] to look at the technological solutions that may be at hand – or to embrace new ones – and there are a whole range of potential tools in that toolbox."
Jones agreed that nanotechnology is unlikely to be a useful tool for going "hell for leather" to produce more food. However, he does not believe there is no role for it in food security. "It could be one of the technologies that reduces water, food waste, packaging waste and the impact of agricultural production."
Jones described this as the "smart answer" to global food security. "If we're going to do this sustainable intensification of food security, it is technologies like nano that have the potential to help us with that sustainability side of the equation."

Quelle: The Guardian
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