Wednesday, November 16, 2011

The Ongoing Quest for In Vitro Meat

For many years, people who think about these things have posited that lab grown meat could replace meat from animals as food, thus eliminating all of the animal cruelty and environmental issues associated with farming animals for meat. "Cultured meat" could be the choice of future carnivores.

However, making this meat is easier said than done. Growing muscle tissues in a laboratory setting is not an easy task, nor, it turns out, is it cheap. Right now, it requires many man hours and expensive supplies and equipment to grow mammalian cells in culture. Muscle cells, the kind that make up the animal meat we eat, also needs to be stretched or exercised in order to develop into tasty muscle. As an additional hurdle, many in vitro mammalian cell culture systems used by scientists use products made from farmed animals. If laboratory meat is going to be made in a way that does not harm animals, components like this are off the table.

Additionally, if people are to eat this in vitro meat, it would have to taste something like meat from animals, and would have to be comparably priced. That requires some advancements in the methods and technology currently used to grow tissue in culture. In an effort to promote innovation on this front, currently PETA (People for the Ethical Treatment of Animals) is offering one million dollars to anyone who can produce and affordable lab-grown replacement for chicken before June 30, 2012.

Recently, however, there has been some progress toward the production of cultured meat. Dutch scientists have created lab-grown meat from bovine stem cells harvested from a slaughterhouse. The "meat" consists individually grown sheets of muscle tissue, grown in culture using Velcro tabs to stretch the fibers so that they develop properly. Right now, the cost of a hypothetical burger made out of this meat, consisting of hundreds of thousands of sheets of muscle tissue, is estimated at $345,000. That's still a little steep for consumers, but the scientists say they plan to produce one as proof of principle within a year. Since the tissue is grown without a circulatory system, it lacks blood and is white in color, and it also lacks the associated fat of meat from an animal. Currently, the scientists say that improving the taste and color, possibly by adding laboratory-grown fat or blood, are goals that they are working towards.

Proponents say that this meat could replace or supplement modern factory farming as a more sustainable, cruelty-free meat product. However, challenges include making the meat palatable, ensuring that the product appears appetizing, and producing it at a cost where it can compete with farmed meat.

Until your laboratory-grown burger becomes available commercially, if you'd like an environmentally friendly, affordable, laboratory-grown protein, you'll have to be satisfied with mycoprotein (which, as an omnivore, I find quite tasty, even though it's not meat).

(via BoingBoing)
(Image: ...meat x 250, a Creative Commons Attribution 2.0 image from x ray delta one's photostream)

Tuesday, November 1, 2011

Probiotics - How Do They Work?

(Image: Yogurt Parfait, a Creative Commons Attribution (2.0) image from mrdestructicity's photostream) 

In the past couple years, there has been a lot of debate (and at least one lawsuit) regarding the effectiveness of yogurt and other foods and supplements that contain "probiotics," or beneficial microorganisms. Various studies have linked the consumption of probiotics to various health benefits, including treatment of gastoenteritis and diarrhea, lowering cholesterol, improving immune function, and reducing inflammation, among other claims. However, most of these studies studied one particular strain of bacteria, so results may not be applicable to all probiotics, and many studies involving humans show correlation with positive health outcomes, but not causation. To date, little is known with scientific certainty about the effectiveness of probiotics, and even less about how they function in the human body.

A recent study has evidence that probiotics may function by altering the expression of genes in your gut bacteria, thereby altering their metabolism of the foods that are present in your gut. After feeding mouse and human subjects probiotics, researchers at Washington University in St. Louis found that, although the composition of gut bacteria were not altered, gene expression of the gut bacteria of the mice were. The effects of the resulting metabolic changes could be observed in the mice's urine.

This study sheds some light on a previously mysterious process. It seems that probiotics may have a real effect on the human digestive system. Hopefully further studies will be able to further elucidate the mechanism of the changes brought about by these organisms and help us to understand which strains may be beneficial and for what purpose.

(via BoingBoing)

Wednesday, September 7, 2011

Yeast Geneology

(Image: S cerevisiae under DIC microscopy, via Wikimedia Commons user Masur)

At the Smithsonian food blog, Food & Think, there is an interesting bit about the origin of lager yeast.

As you may know, most beer we drink is brewed with a species of yeast called Saccharomyces cerevisiae. Depending on the type of beer, a different strain of this yeast is used. For ales, brewers use a strain of ale yeast, which ferments more or less at normal room temperatures (15-20C) and is known as top-fermenting yeast. For a lager, one would use a lager yeast, which is a bottom fermenting yeast that functions at cooler temperatures (around 5C). Additionally, lager yeast is able to digest raffinose, a sugar present in wort (unfermented beer) that ale yeast cannot ferment. This means that lager yeast can contribute to a higher sugar-to-alcohol conversion and results in a less sweet beer.

Previously, scientists had compared the genomes of lager and ale yeast and found that lager yeast resulted from a cross between S. cerevisiae and another type of yeast. Recently, this type of yeast, which was previously undescribed, has been identified, as described in a recent paper in PNAS. Interestingly, this yeast is native to South America, suggesting that modern lagers (even European ones) owe many qualities to a species of New World yeast. Previous to the European exploration of the Americas, lagers in Europe may have been brewed with unhybridized S. cerevisiae, resulting in a different beverage than what we identify as lager beer today.

It seems that globalization hasn't been such bad news for beer, after all.

Wednesday, August 31, 2011

Food & Think

I recently discovered a really intelligent and interesting blog about food over at the Smithsonian Magazine website: Food & Think. It's the thinking person's food blog, full of information about the culture and history of food, with great tie-ins to current (non-food) events (see several posts relating to the recent hurricane situation in the Northeast). You should go check it out, right now!

Friday, June 24, 2011

Archaeology of Beer

 The Smithsonian Magazine website, there is a really interesting article about brewers trying to re-create fermented beverages as they might have been made thousands of years ago. (One familiar example of this is the Dogfish Head Brewery's Midas Touch, pictured above, a beer based on an Iron Age recipe including Muscat grapes, saffron, and honey.) Many brewers have enlisted the help of Patrick McGovern, an archaeologist from the University of Pennsylvania specializing in ancient libations. Go check out the article, and maybe it will inspire you to brew your own version of an ancient brew!

(Image:  Dogfish Head Midas Touch, a Creative Commons Attribution (2.0) image from add1sun's photostream)

Tuesday, May 17, 2011

Gin, Tonic, and Temperature

The weather is getting warmer. You'd like to sit outside in the sun, enjoying a cold beverage. However, while you're sipping your gin and tonic on the rocks, your ice is slowly melting. A drink without ice gets warm quickly, but a drink with ice becomes watered down while you're drinking. Oh cruel fate!

What's the solution? Science!

The good folks at Kaiser Penguin have tested (and graphed!) several possible solutions to the problem of how to make a temperature-controlled drink. So, go get your geek on and check out the way to make an optimized gin and tonic!

(via BoingBoing)
(Image:  Gin and Tonic, a Creative Commons Attribution (2.0) image from Global Jet's photostream)

Thursday, April 7, 2011

The Perfect Bloody Mary

Here at Food/Science, we love us some brunch cocktails. Luckily, some folks with Ph.D.'s spent time and effort to determine, scientifically, the best way to make one such libation: that brunch classic, the Bloody Mary. At a recent meeting of the American Chemical Society, scientists presented research showing that, basically, it boils down to using fresh, quality ingredients and cheap vodka. Hooray for thriftiness, and science!

Personally, I like mine garnished to the hilt, with pickles and olives a must.

Check out the full story here, (via The Kitchn).

Also, as a bonus, why not pair your scientifically-proven Bloody Mary with a Mobius Bagel? So much geekery, in one brunch!

(also via The Kitchn)

Monday, April 4, 2011

Farm Subsidies and Obesity

At Good, Robert Paarlberg argues against the popular belief that federal farm subsidies contribute to obesity in America. Paarlberg says that most farm subsidies actually increase the price of foods, and that the argument that unsubsidized healthy foods have increased in price relative to unhealthy, processed foods is untrue. Therefore, food subsidies can't be blamed for American's poor diets and resulting health woes. It's a well-written, well-researched piece - definitely food for thought (ahem) about the causes of unhealthy diets in America and what should be done about them.

Wednesday, February 9, 2011

The Science of Cooking with Beer

Via BoingBoing, there is an interesting article about why beer batter makes fried food delicious at Scientific American. In short, beer contains three things that make it a great batter ingredient: foaming agents, carbonation (a.k.a. dissolved carbon dioxide), and alcohol. Carbon dioxide is more soluble in water at cold temperatures, so when beer batter is heated it releases bubbles of carbon dioxide that are trapped by the foaming agents (in most beers this is carbohydrates and proteins from the barley malt), making a light crispy crust. The pockets of air in the crust insulate the delicate food inside, allowing it to gently steam and keeping it moist. The alcohol in beer batter boils at a lower temperature than water, meaning that, when cooked, this batter releases moisture faster than batter made with just water, allowing it to cook faster. Only after all of the water and alcohol have evaporated will the Maillard reaction* take place, making starches and proteins in the batter golden brown and delicious.

*Note: The article says that the Maillard reaction takes place above 130 degrees Fahrenheit, but this is incorrect. It actually takes place above 130 degrees Celsius, which is about 265 degrees Fahrenheit.

Another good reason to cook with beer, and not necessarily just in beer batter, is that beer adds great flavor to dishes. Beer contains its own flavors - smoky, sweet, bitter, or acidic, or a combination of these, depending on the variety. Beer also contains alcohol, which helps amp up other flavors in a dish. Alcohol is able to dissolve many flavors that are not very soluble in water, like essential oils and other organic compounds. These compounds are key flavor components of foods like black pepper, chili peppers and tomatoes, among many, many others. This means that adding any alcohol-containing liquid to a dish can dissolve these flavor compounds, making them more available to your taste buds and increasing their flavor.

In case all of this had put you in the mood to cook with some beer, I've included a recipe below for Black Bean and Sweet Potato Chili, which I whipped up for the Superbowl last Sunday. It's delicious, cheap, and healthy, and the dark beer included in the recipe adds a little smoky flavor as well as some alcohol to dissolve the spicy and tomato flavors in the chili.

Monday, January 24, 2011

New Variety of Cacao

(image via Wikimedia Commons)

In the New York Times, there is an interesting article about a recently re-discovered variety of Cacao, the plant from which chocolate is produced. This variety, known as Nacional, was formerly widely grown in South America prior to this century, but was mostly wiped out by disease. Today, the variety is very rare, but recently a genetically pure specimen was discovered and is now being made into chocolate.

Apparently this variety is unusual in that some of the cacao beans are white instead of their normal purple color, and yield a less bitter chocolate because they contain fewer anthocyanins, pigment molecules that have an astringent taste. Currently there is only one retailer of chocolate made from this newly discovered variety in the US, Moonstruck Chocolate.

This story makes me think about how plant breeding (and inbreeding) will affect the varieties of food plants that will be available to us in the future. Originally, Nacional cacao trees were wiped out by a disease to which all plants of that variety were susceptible. Among other reasons, one explanation for the severity of the infamous Irish potato famine was that many farmers were cultivating one variety of potato, which all had similar succeptibility to Blight, a plant disease. This famine killed nearly one million people. Some people predict that a similar fate will befall modern banana farmers, since almost all bananas grown for sale in the US are of one variety and grown from genetically identical trees.

Growing many varieties of one type of plant makes growing and harvesting the different varities more complicated and threfore more expensive, but it is a good way to maintain a diverse selection of plants and avoid your entire crop being decimated by one disease. Maybe in the future agriculture will find a balance between variety and cost efficiency. It's also possible that the days of bananas as we know them are numbered.

(Thanks to Lynn for the tip!)

Friday, January 14, 2011


From BoingBoing, a cool article about how to make yourself a DIY sous-vide waterbath for around $75. Normally, buying one of these puppies would cost a couple thousand.

Sous-vide is a method of cooking things in a water bath, sometimes called an immersion-circulator, in a plastic bag. It literally means "under-vacuum," a reference to the method of vacuum-sealing food in a plastic bag before cooking via this method. It's become quite trendy as of late, especially with the molecular gastronomy set.

In the above post, they point out one great use of the sous-vide method: cooking an egg. Previously on this blog, we've discussed protein denaturation, even specifically as it relates to eggs. That is, the way that proteins unfold when exposed to high heat or another denaturing environment. Egg proteins denature and coagulate at fairly low temperatures, much lower than the boiling point of water, for instance. By boiling or frying an egg, we transfer a lot of heat to the egg very quickly and rapidly denature and coagulate the proteins. By instead using sous-vide, you slowly bring the egg proteins to the point at which they denature and coagulate. The temperature does not exceed this point, so the egg attains a texture unlike that of eggs cooked using any other method. Of course, this takes much longer than frying an egg - cooking anything sous-vide takes longer since the difference in temperature between the food and the surrouding cooking medium is lower. I'm sure Ferran Adria would say it's worth the wait.