How the Sugar Fungus, Yeast Shaped Civilization

Menaka Wilhelm wrote . . . . . . . .

An imagined conversation between two yeast cells appears in Kurt Vonnegut’s 1973 novel Breakfast of Champions. “They were discussing the possible purposes of life,” Vonnegut writes. If that’s not absurd enough, their existential discussion takes place against a weird, dismal backdrop, “as they ate sugar and suffocated in their own excrement.” Little did they know, their little yeasty lives had an important, human-centric purpose. “Because of their limited intelligence, they never came close to guessing that they were making champagne.”

Besides the beverages yeast ferments, and the loaves it raises, the single-celled fungus has had its figurative fingers in all kinds of important products throughout history. Yeast matters for so many different things, says Nicholas Money, author of the newly published book The Rise of Yeast, that it ranks as “a secular deity, something to be revered as much as the warmth of the sun.”

Money points out many of those contributions throughout The Rise of Yeast: How the Sugar Fungus Shaped Civilization. Here are a few of the surprising places yeast has changed the way we eat and live:

Fermentation may have enticed nomadic communities to settle down

For a long time, humans traveled often and foraged for food, rather than growing it. And that worked pretty well, so anthropologists have long puzzled over why people started settling in a single spot. One benefit to nesting: growing grapes and grains, and staying in a place long enough to brew beverages for weeks or months, as beer and wine require. “Some posit this as the reason that civilization began in villages surrounded by golden fields of barley and rows of grapevines on the hills,” Money writes.

In its day, beer foam helped raise a few loaves of bread

It’s not totally clear how the first-known leavened breads, in Egypt, began to incorporate yeast. Wild yeast will grow on its own if a dough sits long enough, the way sourdough works. In Roman times, though, Pliny the Elder wrote about bread dough incorporating beer froth for lightness. Some early commercial yeasts in Europe relied on beer byproducts for microbial help, too, but baker’s yeast today consists of separate, specialized strains.

Yeast elevates chocolate and coffee

Both cocoa and coffee beans undergo a fermentation step after their harvest, where yeasts munch on sugars surrounding the beans. Bacteria also play a role in this process, and the yeast leaves behind flavor compounds that make it into the final coffee and chocolate. Researchers have found that cocoa beans in yeast-free fermentation are left with an acidic, off flavor, and that certain yeasts can lend coffee caramel notes.

The riot of microbes that ferment kombucha includes more than one kind of yeast

“Fission yeast, Saccharomyces, other yeasts, and accompanying bacteria occupy a slimy slab called a zoogleal mat that sits atop the fermenting tea,” Money writes. Another name for that zoogleal mat, SCOBY, stands for “symbiotic colony of bacteria and yeast.”

That suffocating “in their own excrement” that Vonnegut mentioned? It caps the alcohol content in wine and beer

Behind every adult beverage, there are strains of yeast that toiled, breaking sugars down and producing alcohol. For yeast, alcohol is more than a tipple — it’s a waste product, and a protection against other microbes that can’t tolerate spirits as well. Take palm wine, Money says. It’s made from palm sap left out in the open, so airborne wild yeasts do all the fermentation. At first, a circus of different yeasts hops into the sap and ferments their hearts out, gorging on the sap’s sugars and releasing carbon dioxide and alcohol. Different yeast strains tolerate different levels of alcohol, so the yeast with the highest alcohol tolerance, a strain of Saccharomyces, soon wins out. “It clears the field, and ensures that it has special access to the sugar,” Money says. But even those winners eventually succumb to their own booze, so the alcohol level plateaus.

For humans, that means any beverage above around 15 percent alcohol requires distillation, or genetically engineered yeasts, which can tolerate higher levels of alcohol. With slightly more time to discuss their life’s purpose, what those new superyeasts talk about is anyone’s guess.

Source: npr

New Graphene Laser Technique Opens Door for Edible Electronics

Electronics, the lifeblood of the modern world, could soon be part of our daily diet. In a study appearing in ACS Nano, scientists report that they have developed a way to write graphene patterns onto virtually any surface including food. They say the new technique could lay the groundwork for the edible electronics capable of tracing the progression of foods from farm to table, as well as detecting harmful organisms that can cause gastric distress.

Graphene is composed of a single layer of carbon atoms arranged in a honeycomb pattern. It is stronger than steel, thinner than a human hair and more conductive than copper, making an ideal building block for the next generation of compact, smart electronics. Several years ago, James M. Tour and colleagues heated the surface of an inexpensive plastic with a laser in air to create something called laser-induced graphene (LIG). LIG is a foam made out of tiny cross-linked graphene flakes. The process can embed or burn patterns that could be used as supercapacitors, radio frequency identification (RFID) antennas or biological sensors. Based on these results, the researchers theorized that any substance with a reasonable amount of carbon can be turned into graphene. To test this theory, Tour’s team sought to burn LIG into food, cardboard and several other everyday, carbon-based materials.

The researchers used a single laser pulse to convert the surface layer of the target substance into a disorganized jumble of atoms called amorphous carbon, more commonly known as black soot. Then, they conducted multiple laser passes with a defocused beam to convert the soot into graphene. By defocusing the laser beam, the researchers could speed up the conversion process. And unlike previous LIG processes, the graphene conversions conducted in these experiments were done at room temperature without the need for a controlled atmosphere box. Overall, the process demonstrated that LIG can be burned into paper, cardboard, cloth, coal, potatoes, coconuts, toasted bread and other foods. The researchers say these results suggests that food items could eventually be tagged with RFID antennas made from LIG that could help track where a food originated, how long it’s been stored and how it got to the dining table. In addition, they suggest that LIG sensors could be used to uncover E. coli and other harmful organisms lurking in salads, meats and other foods.

Source: American Chemical Society

Waffles with Blueberry and Maple Syrup Sauce

Ingredients

1 cup all-purpose flour
2 tsp baking powder
1 1/2 tsp sugar
1 1/2 whole eggs
3/4 cup milk
1/4 cup butter, melted
Vanilla, to taste

Sauce

2 cups frozen blueberries
8 cups water
1/2 cup sugar
2 Tbsp brown sugar
2/3 cup white wine
2/3 cup maple syrup
1/4 cup sherry
1 Tbsp cornstarch

Method

1. To make the sauce, in a saucepan, bring blueberries and water to a simmer. Add sugar, brown sugar and white wine. Reduce for 10 minutes.
2. Mix sherry and cornstarch to create a slurry. Add to blueberry mixture and bring to a boil. Reduce for 5 minutes
3. Mix flour, baking powder, sugar and eggs. Add milk and butter, mix until smooth. Adjust vanilla to taste.
4. Pour a 1/2 cup at a time into waffle maker. Cook until light brown in colour.
5. To serve, place waffle in centre of plate. Drizzle with the sauce. Serve remaining sauce in creamer.

Makes 12 servings.

Source: ciao!

In Pictures: Breakfast Toasts

Daily Aspirin Can Bring Heart Benefits for Some People, But Risks Too

For people who have both type 2 diabetes and heart failure, new research offers a mixed message on taking a daily low-dose aspirin.

The study found the daily pill can reduce the risk for heart failure-related hospitalization and death in people who have both conditions. However, it also found that a daily aspirin raises their risk for nonfatal heart attack and stroke.

The findings came from the analysis of data from more than 12,000 residents of the United Kingdom, 55 and older. They all had heart failure and type 2 diabetes, but no history of heart attack, stroke, peripheral artery disease or the heart rhythm disorder atrial fibrillation.

During a five-year span, those who took a low-dose aspirin a day were 10 percent less likely to have been hospitalized or to have died because of heart failure than those who did not. But they were 50 percent more likely to have had a nonfatal heart attack or stroke.

Aspirin is a blood thinner that reduces the risk for blood clots. Both heart failure and diabetes increase the risk for blood clots that can lead to heart attack and stroke. About 27 million people in the United States have type 2 diabetes, and about 6.5 million U.S. adults have heart failure, the researchers said.

Though a low-dose daily aspirin is recommended for people who’ve had a heart attack or stroke, its use as a preventive treatment in people with heart risk factors but no history of heart attack or stroke is unclear, according to the study authors.

The findings are to be presented at a meeting of the American College of Cardiology, in Orlando, Fla.

Some studies have even suggested that daily aspirin might be harmful for people with heart failure, the researchers noted.

Lead author Dr. Charbel Abi Khalil said his team was surprised to find that taking a low-dose daily aspirin increased the risk for nonfatal heart attack and stroke among the study participants.

“This finding might be due to the fact that those patients lived longer,” he said in a meeting news release. “Given their mean age of 70 years, perhaps these patients were predisposed to more cardiac events.”

Abi Khalil is an assistant professor of medicine at Weill Cornell Medicine in Qatar.

He urged people to talk with their doctors to assess the possible benefits and risks of taking a daily aspirin.

Source: HealthDay

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