Discreet Meat Deceit

Posted on March 3, 2013 by Dan Jenkinson

As you’re probably aware, horse meat has been found in many of the UK’s cheaper ‘beef’ products. This led to an investigation which discovered that this is happening all over Europe, including Sweden, Switzerland, Germany and France. Personally, I don’t mind, but a lot of people are creating a lot of noise about it, so it must be pretty important. I think maybe its the fact that people have been mislead. But how was the horse meat initially discovered in these products?

Corse or How?

Some of the products tested showed a positive result for equine DNA – but if DNA is, at the end of the day, made of exactly the same building blocks in every living species on earth, how can you identify horse DNA from cow DNA from human DNA? Every individual living thing on the earth has their own unique DNA sequence (except identical twins) otherwise we’d all be clones of each other, and there are certain genes that must be present in each species in order to make them look how they do. An example would be the genes that give horses a single hoof and cows a cloven hoof on each foot, or the genes that give the horse one stomach chamber but the cow four.

The DNA sequences of many, many animals have been catalogued, and so if a sample of meat is subjected to a DNA test, you can compare the genetic material in the meat to the ‘generic’ horse genome, and if horse meat is present, you know you have it in your sample!

DNA

So, what are the implications of having horse meat in our burgers, lasagnes, etc? Horse meat is cheaper than beef in some countries, so using it can drive the price of products down. Horses are also fed a drug called bute as an anti-inflammatory, but it is actually lethal to humans at high enough concentrations, but you’d have to have a lot of it to kill you (it is still used as a last resort for extreme cases of spinal arthritis in humans – but only a last resort as the side effects are quite serious).

My opinion is that horse meat is leaner, apparently more succulent than beef, and is considered a delicacy in many countries, so maybe we should start too? Original post and personal blog at http://danthechemist.wordpress.com/2013/03/03/discreet-meat-deceit/

Ultra-Ever Dry

Posted on February 24, 2013 by Dan Jenkinson

I was recently offered a place at the Molecular Scale Engineering Centre for Doctoral Training based between Sheffield and Leeds universities, which I was more than happy to accept. Given that I will have a choice about what I’ll be doing, it got me thinking about the types of chemistry done at the centre and the applications that they have in real life. The popularity of surface modification chemistry is growing – I’m even doing some for my fourth year project – and it seems as though this area has almost limitless potential. For example, have a look at this video…

http://www.youtube.com/watch?v=IPM8OR6W6WE&w=560&h=315

How awesome is that?! The secret to this kind of technology is to change the properties of the surface to make it hydrophobic (hydro = water, phobic = fear, i.e. hydrophobic things repel water). The Ultra-Ever Dry website claims that the hydrophobic surface creates a barrier of air to stop itself from getting wet… but what does this mean?

The hydrophobicity of a surface (how hydrophobic it is) can be calculated using the contact angle it makes with a droplet of water. The contact angle is the angle between a surface and a fluid at their interface, illustrated below. Ultra-Ever Dry say that surfaces coated with their material have a contact angle of around 170 degrees, making them ultrahydrophobic. This is pretty impressive considering that a contact angle of 180 degrees would make the surface perfectly non-wetting.

Hydrophilic (water loving) surfaces have much lower contact angles than hydrophobic ones. Ultrahydrophobic surfaces have contact angles bigger than 150 degrees.

But not only do Ever Dry coated things repel water, they also repel fats and oils (making it oleophobic). If you’ve ever tried to mix water and oil, you’ll know they don’t mix, and this is because they have completely different properties – so how can this material repel both? I’ve contacted the company to see if they will reveal any more information about how it works, but it’s not likely that they will share very much.

My guess is that the molecules deposited onto the material interact so strongly with oxygen in the air that anything else that tries to reach the surface can’t get past the oxygen molecules. I’ve done my best to explain that using a crudely drawn diagram here…

My best guess on how I think Ever Dry might work based on my knowledge of chemistry now and what is said on the product’s official website

If representatives from the company ever get back to me to reveal their trade secrets, I will let you know! To find out more about me, my research and to read my other posts, you can follow this link to my personal blog: http://danthechemist.wordpress.com/

Scientists Implant Biofuel Cell in Living Snail

Posted on April 23, 2012 by Maria

By Maria Panagiotidi

Researchers led by Evgeny Katz, the Milton Kerker Chaired Professor of Colloid Science at Clarkson University, have implanted a biofuel cell in a living snail. Their findings were published in the Journal of The American Chemical Society.

Researchers led by Evgeny Katz, the Milton Kerker Chaired Professor of Colloid Science at Clarkson University, have implanted a biofuel cell in a living snail. This is the first incidence of an implanted biofuel cell continuously operating in a snail and producing electrical power over a long period of time using the snail’s physiologically produced glucose as a fuel. (Credit: Image courtesy of Clarkson University)

The “implanted battery” can generate electrical power for several months driven by glucose, which is produced by the snail.

This is the first reported incident of an implanted biofuel cell operating in a snail and producing electrical power over a long period of time using as fuel the glucose that is physiologically generated by its host.

Implantable biofuel cells have been suggested as sustainable micropower sources operating in living organisms, but such systems are still very challenging to design. In the future, implanted fuel cells that are driven by glucose generated by their host could power medical devices in humans or environmental sensors in animals.

Evgeny Katz and his colleagues made the electrodes of their fuel cell out of densely packed carbon nanotubes, and attached glucose-oxidizing and oxygen-reducing enzymes to them. The authors then implanted the electrodes into a snail (Neohelix albolabris). After decreasing the rate of current extraction to match the snail’s slow glucose transport and metabolism, they got continuous electrical output for an hour. The amount of electricity produced was far below that of just one AAA battery, but the group of scientists aim to increase it in future experiments. The fuel cell remained functional in the snail for several months during which the animal was allowed to roam freely and live an almost normal life.

The aim of this research is creating insect cyborgs, an idea that has been funded by the U.S. Department of Defense.

Reference

Lenka Halámková, Jan Halámek, Vera Bocharova, Alon Szczupak, Lital Alfonta, Evgeny Katz. Implanted Biofuel Cell Operating in a Living Snail. Journal of the American Chemical Society, 2012; : 120308155036002 DOI:10.1021/ja211714w

You can find the article here: http://pubs.acs.org/doi/abs/10.1021/ja211714w

The Chemistry of Chocolate? Eggcellent.*

Posted on April 10, 2011 by Holly Rogers

Part I

With Easter coming up, and so many people giving up their sweet tooth for Lent, it seems like chocolate is on everyone’s mind. So what better topic for my first blog post for Science Brainwaves than the science of chocolate…

The first record of chocolate dates back to around 1500 BC, when the Aztecs and Mayans began drinking a cold, bitter mixture of cocoa and water. They named this cacaoatl, which literally translates to “foamy water”. Delicious. Three thousand years later, chocolate reached the European mainland, and from then on, there was no stopping it. By 1831, John Cadbury was selling drinking chocolate, and in 1876, Nestle released the first bar of milk chocolate onto the market.

Despite the huge variety of chocolate on offer in the shops, the basic recipe is very simple – cocoa butter, sugar, cocoa solids and milk solids. The difference in taste comes mainly down to different amounts of each ingredient, although dark chocolate has no milk solids (which is why it tastes less “creamy”) and white chocolate has no cocoa solids, which explains the pale colour.

The way cocoa beans are processed are the key to how the end result will taste. After being picked, they’re fermented for about a week, dried for a fortnight and then transported to a factory. Fermenting the beans adds around 30 new chemicals to the mix, some useful and some not, so at the factory, the beans undergo a process known as the Maillard reaction. It has at least 9 steps, and converts the amino acids in the cocoa beans (which don’t taste of anything) to aldehydes (which generally taste great). Depending on how hot the reaction is, how acidic you make it and how long you run it for, you can get over 1000 different tastes from the Maillard reaction, including coffee, caramel and roasting meat.

Next, cocoa solids (made from grinding the beans) are conched. This means warming them up, grinding them with sugar and blowing air over the top. The heat removes any volatile (easily evaporated) chemicals from the beans, and the air whisks them away. The main thing removed from the beans is acetic acid, which is more commonly known as household vinegar.

Conching the cocoa solids decides what quality the chocolate is. The smaller they get, the better the chocolate – anything greater than 0.03mm (0.003cm, or three hundred thousandths of a metre) wide and the chocolate will feel gritty in your mouth. European chocolatiers, like the Belgians and Swiss, prefer very, very fine particles, which makes it melt more slowly in your mouth, and explains why European chocolate is more expensive.

A useful tip is to never store chocolate anywhere too warm or too cold. If you leave it in a warm room, you get a “fat bloom” – the white powder you sometimes find when you keep an Easter egg for too long, or forget about the Dairy Milk in your handbag. The increased heat means the fat rises to the top where you can see it. You can get rid of the bloom by gently warming it, then letting it cool down slowly, but it’s tricky to get it right without ending up with a puddle of chocolate. If you keep your chocolate in the fridge, you’ll get a “sugar bloom”. Any water vapour inside the fridge or the packet will collect on the surface of the chocolate as it cools down, dissolving any sugar it can reach. This eventually crystallizes on the top, giving you a gritty layer of sugar on your chocolate. There’s no way to undo this, so store your KitKat at room temperature for the best taste and texture.

* Well done if you made it past the pun! The alternative was “The Easter Bun(ny)sen.” In part II, I’ll be looking at why chocolate makes you feel good, and how it can help you stay awake. Title suggestions gratefully received!

The Science of Cocktails

Posted on March 8, 2011 by Michaela Livingstone

What happens when you bring together a thirsty and fun-loving group of the public and a chemist with a deep interest in alcoholic beverages together? Answer: …A night many might not remember, but nevertheless, utterly intriguing and fun! The science of Cocktails event took place last Friday, all punters leaving happy!

75 people who came dressed to impress, packed in to the Common Room in University House, situated in the Students’ Union and learnt about where alcohol comes from, what gives vodka and whiskey their tastes, how to get the most out of your spirits, and how to make your own cocktail combinations… Though I thought it was all going to go downhill when the first slide of the presentation stated: ‘All alcohol is poisonous’. Quite true, we don’t condone binge drinking, but everything in moderation! The night ended, quite appropriately, on a look at what hangovers are, and how to avoid them.

Throughout the night, attendees were invited to taste, smell and mix drinks for themselves, starting the night off with a fizz in the shape of a lovely champagne and brandy-based cocktail, comparing vodkas, whiskey tasting, making a screwdriver, ending the night on a proper Irish coffee. The hangover advice being handy… I’m told…

There’s no doubt that our rather dapper host for the night, Noel Jackson, trained chemist, Head of Education and resident mixologist from the Centre for Life up in Newcastle, knew his stuff! Having come up with the Cocktail Hour after thinking of ways to engage 18-30s with science. The answer seemed to be sex, drugs and rock’n'roll! Aside from the insight in to the chemistry of alcohol production for example (did you know your cheap vodka comes from oil refinery!), there were countless insights in to the history, aetiology, sociology and geography of cocktails and various spirits! An extremely eye-opening and sometimes mind-blowing experience.

Organised by our ever-wonderful secretary Tacita Nye, and supported by the committee and our volunteers, it went fantastically, so I’d like to take the opportunity to thank Tacita and Noel for making it so enjoyable, and all the hard-work that our volunteers did to make it the success it was.

“The evening was a perfect balance of science and everyone’s favourite pastime – drinking!” Tacita said in summary of the night, her favourite part was when attendees mixed up their own screwdrivers, “there really were some interesting combinations!”

One of our past committee members made the trip up from London and broadcast this via twitter:

BekiHill
Science of cocktails w/ @scibrainwaves was great, but definitely feeling a bit worse for wear now!

Jon Banks, a self-confessed whiskey lover who attended the event, left us this message on our Facebook:

“Thanks Brainwaves for an awesome night of science and cocktails! I learned all about distilling, hangovers, and why you should always drink scotch with water! I even remember some of it!”

We also tested out our budding mixologists’ knowledge by doing the Big Cocktail Quiz – three lucky winners took home some wine and some guides and recipe books on cocktails, to carry on the fun when they got home.

This was our first ever adult-only night. Usually we’re out and about ranting and raving about the awesomeness of science to anyone who will listen! We’re really pleased it was so successful, in fact, watch this space for a botanics of Gin night! Whilst we had to charge entry for this event to cover the costs of alcohol and so on, we were extremely grateful to all the donations that people generously gave us so that we can continue to put on free events, for children, families and, well, everyone!

Thanks to Ron Adams for taking pictures on the night, and some of the attendees; Adam Dobson, Paul Clarkin and Beany Rosic, for sending in their pics!

Study Scientifique

Posted on June 27, 2010 by admin

And for my first trick… let me bring your attention to Study Scientifique, a post I did for the Craft Candy blog last year. The Art-Science Adventures blog will catalogue the crafty side of science - be it oversized stuffed microbes, DNA-banded bangles or crochet crystal structures. Check back here for featured DIY projects and tutorials, downloadable freebies, new and noteworthy articles, and excellent one-of-a-kind gift ideas for Scientists.