This technology can't make a tastier smoothie, but it sure could produce a healthier one.
Scientists have fortified foods with nanoparticles made from iron and zinc.
These minerals are easily absorbed, but foods may lack their original color, taste and smell.
Nanoparticles could help 2 billion worldside affected by anemia or zinc deficiency.
Food enriched with nano-sized minerals could soon make billions of people in developing countries healthier.
Scientists from Switzerland have designed new iron and zinc nanoparticles that solve a longstanding conundrum in food fortification: how to make food more nutritious without changing its taste. The research could help eliminate anemia and zinc deficiency across the globe.
"Iron and zinc deficiencies are common around the world," said Michael Zimmermann, a scientist at ETH Zurich and a co-author of a recent Nature Nanotechnology article. "Yet many compounds used in food fortification are either absorbed poorly or, when they have high absorption, change the color, taste and smell of food."
Anemia, or a lack of iron, affects more than 2 billion people worldwide and is arguably the most widespread micronutrient deficiency. Without enough iron the the body can become lethargic and cognitively impaired. For some pregnant women, the lack of iron can kill them during childbirth. Some economists have even speculated that a nation's gross domestic product is depressed because of anemic and lethargic workers, said Zimmermann.
Lack of zinc impairs a person's normal growth and can lead to diarrhea, pneumonia, anorexia and other conditions.
Food scientists typically fortify foods with two different forms of iron. The human digestive track easily absorbs them. The human eye, tongue, and nose, however, do not like large amounts of the mineral, which can turn an ordinarily brown chocolate milkshake green or blue.
The other way to fortify food is with ground iron particles. Usually added to wheat and other grains, these tiny amounts of the mineral don't alter the look or taste of food, but they aren't absorbed very well either..
The new research solves this conundrum. To create the nanoparticles the Swiss scientists dissolved iron in water, then sprayed the solution over very hot fire. The intense heat quickly evaporates the water, leaving tiny iron or zinc crystals, each one about 10 nanometers across. Those nanocrystals then clump together.heat
The large clumps do not change the taste, color or smell of food. When the clumps drop into the stomach acid, however, they break apart into tiny particles, which are easily absorbed by the body.
The scientists added the nanoiron to chocolate milk and a banana smoothie, and then fed them to rats. Since they were fed a low-iron diet, the rats were anemic. The rodents drank the fortified fluids and exhibited no unusual behavior.behavior
The team had similar results using zinc nanoparticles, said Zimmermann. Zinc deficiency, while undoubtedly harmful, isn't as debilitating or widespread as anemia.
No humans have yet tasted the iron and zinc nanoparticles. "But I would drink them," said Zimmermann.
Human trials are the next step in Zimmermann's research. There is no reason to expect there would be any problems consuming the nanometal. The human body is supposed to absorb iron, and most people don't consume enough anyway.
This is a new material, however, said Dennis Miller, a food scientist at Cornell University in New York. More research is needed before humans actually consume it.
Chances are nanoiron is perfectly safe for humans to consume, said Miller, but there is a slight chance that the tiny nanoiron particles could bypass normal iron absorption mechanisms and overload the body.
Overall though, the new research is a big step forward for food fortification. "A lot of time and effort has been spent over many years to come up with an iron fortificant that is bioavailable but doesn't change the color or flavor of food," said Miller. "This one has real potential."flavor