04 January, 2009

Sunday Sensational Science

Scientists Play With Their Food

It's that time of the year when we've probably filled ourselves with more food than we could hold. Before the diet begins, let's hold one last feast, courtesy of science.

Scientists studying food have made our harvests more bountiful, our turkeys bigger, and are discovering new foods for us to serve up. They'll make it possible to eat green, eat well, and eat healthy. Not bad results for a bunch of guys in lab coats playing with food, eh?

Wired Science often has delightful articles on food-related science. I've chosen out appetizers from some of their recent offerings for your dining pleasure. Be sure to click through for the full meal. Bon appétit!



Science Behind Mysterious 'Fifth Taste' Revealed

It's appetizing news for anyone who's ever wanted the savory taste of meats and cheeses without actually having to eat them: chemists have identified molecular mechanisms underlying the sensation of umami, also known as the fifth taste.

The much-loved but historically unappreciated taste is produced by two interacting sets of molecules, each of which is needed to trigger cellular receptors on a tongue's surface.

"This opens the door to designing better, more potent and more selective umami enhancers," said Xiaodong Li, a chemist at San Diego-based food-additive company Senomyx. Li co-authored the study, published Monday in the Proceedings of the National Academy of Sciences.

Four other basic tastes — bitter, sweet, salty and sour — were identified 2,400 years ago by the Greek philosopher Democritus, and became central to the western gastronomic canon.

In the late 19th century, French chef and veal-stock inventor Auguste Escoffier suggested that a fifth taste was responsible for his mouth-watering brew. Though Escoffier's dishes were popular, his theories were dismissed until 1908, when Japanese chemist Kikunae Ikeda showed that an amino acid called glutamate underlies the taste of a hearty variety of seaweed soup.

In honor of Ikeda, the taste was dubbed umami, the Japanese word for delicious. It took another 80 years for umami to be recognized by science as comparable to the other four tastes.


From Salon to Salad: Human Hair Makes Good Plant Fertilizer

Human hair could be used instead of chemical fertilizers for some plants like lettuce, new research in a horticultural journal suggests.

The hair, which is manufactured into cubes from barbershop and hair-salon waste, provides nitrogen for plants as it decomposes, just as natural-gas-derived sources like ammonia do.

"Once the degradation and mineralization of hair waste starts, it can provide sufficient nutrients to container-grown plants and ensure similar yields to those obtained with the commonly used fertilizers in horticulture," said horticulturalist Vlatcho Zheljazkov of Mississippi State University.

All plants need nitrogen to grow. These plants form the basis of the proteins which eventually make their way into our bodies either directly through the consumption either of the plants themselves or of animals raised on plants. Our bodies turn those proteins into all sorts of useful things — like muscles — and some less useful things, like hair. In fact, studies carried out in the 1960s found that human hair contains about 15 percent nitrogen [pdf].



A Willy Wonka Who Wants to Feed the World

Ask America's foremost molecular gastronomist about the Willy Wonka comparisons, and Homaro Cantu will insist that he's just an average guy who likes cheeseburgers. But it's not cheeseburgers that have earned the Chicago chef fame: it's dishes prepared with industrial lasers, inkjet printers and liquid nitrogen.

Look beneath the technical sophistication, though, and Cantu's kitchen pyrotechnics are revealed as explorations of possible answers to a very simple question: What is food? And if the cuisine at Moto, his "molecular tasting lab," can be described as postmodern, Cantu himself has little time for gastro-academic posing. He's driven by a techno-utopian vision of decentralized food in which the world's ever-growing appetites are met by a radical transformation of agriculture itself — and it all begins in our kitchens.

"Make enough food for everyone. That's the end game," says Cantu. "And to get there, we have to start thinking a little crazier about what food is."


Food vs. Fuel: Saltwater Crops May Be Key to Solving Earth's Land Crunch

Saltwater-loving plants could open up half a million square miles of previously unusable territory for energy crops, helping settle the heated food-versus-fuel debate, which nearly derailed biofuel progress last year.

By increasing the world's irrigated acreage by 50 percent, saltwater crops could provide a no-guilt source of biomass for alt fuel makers and tone down the rhetoric of U.N. officials worried about food prices, one of whom called the conversion of arable land to biofuel crops "a crime against humanity."

While growing crops in saltwater has been on the fringes of horticulture for decades, the new demand for alternative energy has pushed the idea onto the pages of the nation's most prestigious scientific journal and drawn the attention of NASA scientists.

Citing the work of Robert Glenn, a plant biologist at the University of Arizona, two biologists argue in this week's Science that "the increasing demand for agricultural products and the spread of salinity now make this concept worth serious consideration and investment."


Genetically Modified Peanuts Could Save Lives


Genetically engineered peanuts may help fight the most common cause of fatal allergic reactions to food in the United States. While the research is unlikely to result in the creation of completely allergen-free peanuts, it could result in fewer outbreaks and even fewer deaths.

For years now, government scientists have been testing ordinary peanuts in the hope of finding one that cannot cause the deadly allergic reactions which kill more than 50 Americans every year. But nature may not be able to provide an answer.

Horticulture expert Peggy Ozias-Akins at the University of Georgia in Tifton is taking a different tack by using genetic engineering to grow hypoallergenic peanuts.

Give Thanks? Science Supersized Your Turkey Dinner

Your corn is sweeter, your potatoes are starchier and your turkey is much, much bigger than the foods that sat on your grandparents' Thanksgiving dinner table.

Most everything on your plate has undergone tremendous genetic change under the intense selective pressures of industrial farming. Pilgrims and American Indians ate foods called corn and turkey, but the actual organisms they consumed didn't look or taste much at all like our modern variants do.

In fact, just about every crop and animal that humans eat has experienced some consequential change in its DNA, but human expectations have changed right along with them. Thus, even though corn might be sweeter now, modern people don't necessarily savor it any more than their ancestors did.

"Americans eat a pound of sugar every two-and-a-half days. The average amount of sugar consumed by an Englishman in the 1700s was about a pound a year," said food historian Kathleen Curtin of Plimoth Plantation, a historical site that recreates the 17th-century colony. "If you haven't had a candy bar, your taste buds aren't jaded, and your apple tastes sweet."

The traditional Thanksgiving dinner reflects the enormous amount of change that foods and the food systems that produce them have undergone, particularly over the last 50 years. Nearly all varieties of crops have experienced large genetic changes as big agriculture companies hacked their DNA to provide greater hardiness and greater yields. The average pig, turkey, cow and chicken have gotten larger at an astounding rate, and they grow with unprecedented speed. A modern turkey can mature to a given weight at twice the pace of its predecessors.

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