Short but sweet

This week’s post comes courtesy of an email from my Dad, so once more, I’m not really doing my own research and my life has been made easy by fortunate coincidence. My topic this time, by pure chance, is sugar.

So, what on earth has sugar got to do with science, I hear you ask. Good question. Well, actually, you were probably all made to learn the structure of glucose (C₆H₁₂O₆ etc.) and all that aerobic respiration and photosynthesis business, which is all very well and quite interesting if you’re into that kind of thing. But you can all look up your notes on that, if it so takes your fancy, or Google it if you really want to know.  I’m more interested in a particularly novel and different use of sugar by an environmental consultancy firm.

My Dad works in the building industry and somehow stumbled against this very interesting and unusual use of sugar in dealing with contamination of a site with hexavalent chromium and chlorinated aliphatic hydrocarbons. Hexavalent chromium (Cr(VI)) is chromium metal in the +6 oxidation state and is known to be a carcinogen, particularly affecting the lungs via inhalation. It’s also a pretty nasty irritant affecting the skin and internal organs if ingested. The sulphate system takes Cr(VI) into cells, where it is reduced to Cr(III) (Chromium in the +3 oxidation state) and then it is thought that some nasty radical chemistry occurs to damage the cell, leading to cancer and other horrible illnesses.  So we don’t really want it in the ground, or anywhere near us, thank you very much. Chlorinated aliphatic hydrocarbons, such as 1,2 dichloroethane, are also carcinogenic and again, definitely not wanted.

But how to get rid of these things in a safe and effective manner? Call in the chemists! The company concerned, RSK, (website found here: www.rsk.co.uk) decided to go for a large-scale injection of molasses into the affected area. Molasses is a by-product of the sugar refining process and is used in cattle feed, or, if from cane sugar, can be used in baking. Molasses from sugar beet contains sucrose, glucose and fructose. Bacteria use these sugars as a substrate for aerobic respiration, depleting the oxygen levels in the soil. This creates a highly reducing environment and the Cr(VI) is reduced to Cr(III) which precipitates as the hydroxide Cr(OH)₃ and can be filtered out of the groundwater. Easy! The reducing environment is also helpful in tackling the chlorinated aliphatic hydrocarbons, as they are reduced step-wise to ethane, ethene, and CO₂ and water. These gases diffuse out of the groundwater and are pretty much harmless. Some clever and careful planning was required to get the conditions just right for the degradation of the chlorinated aliphatic hydrocarbons but the process required no complex chemicals and was definitely economically viable. I was really impressed with the use of something that can be found in my store cupboard at home to tackle a real, scientific problem. You could call it sweet success!

Drink & be merry?

My second post- 4 months after the first. Woops! In my defence, m’lud, it was the summer vacation and my life was taken over by my summer job, socialising with colleagues and a bit of travel thrown in for good measure. Strangely, there is actually more time during term to think and write than there is when I’m at home. All the plans that I had for interesting baking combinations, reading and research went out of the window.  Now I’m back in Oxford and five weeks into my fourth year, scary as that sounds. This year is all about a research project that I am undertaking in the department and it is brilliant fun. Free(ish) weekends also mean more time to spend in the kitchen and reading up on interesting scientific food-related things. (As mentioned previously, I’m still a little bit vague on what this is all about!) However, this time, I haven’t really done too much research. I was fortunate enough to stumble across the inspiration for this post whilst catching up on the news, and then to realise that I had something very relevant in some lecture notes from last year. Yes, that’s right- my degree is actually useful sometimes! And on what topic have I been so well educated? That would be alcohol.  Oh yes. Of course, I’ve tried to teach myself a lot about it, too.  Investigating one’s subject outside of lectures is most important!

Many of us enjoy a glass or few with a meal, or without a meal quite a lot of the time. There are lots of wonderful, interesting varieties of alcohol, and some not-so-nice ones. What makes it the perfect subject for a science blog is that it contains a simple organic molecule, which most people have heard of and we geeky scientists love to use as proof that what we do CAN be cool! This molecule is ethanol. Two carbons, six hydrogens and an oxygen. Sounds harmless enough, doesn’t it? But we all know the effects, whether from first-hand experience, witnessing others under the influence or those films they show us in school to try to scare us away from the stuff.

A recent article on the BBC News website, written by a social anthropologist (found here http://www.bbc.co.uk/news/magazine-15265317), addressed the message we give out and receive about alcohol and the attitude it engenders. Kate Fox believes that the typical behaviour induced by consumption of alcohol is a result of the information we are given. In her view, we are told that alcohol makes us lairy, aggressive, incoherent and more prone to risky behaviour, so we allow ourselves to behave that way when we’ve had a drink. “I was drunk” has become an acceptable excuse for anti-social, frankly awful, behaviour. True, it’s almost expected that a night out involving alcohol will require some apologies the next day and a massive Facebook de-tagging session when your friends decide to be unkind and put the photos of you indulging in daft/disgusting/promiscuous/ all of the above activities on the internet. We’ve all been there or seen it, especially we students and I’m sorry to say that it can be amusing and doesn’t attract the censure it should.

The idea that our behaviour under the influence of alcohol is moderated by cultural expectations sounds very plausible and many aspects of Fox’s argument ring true. However, is she justified in claiming that “The effects of alcohol on behaviour are determined by cultural rules and norms, not by the chemical actions of ethanol?” Whilst she makes a very good point and I agree that we do need a cultural revolution in our attitude towards alcohol- one is always responsible for one’s actions, even under the influence, and each individual has the responsibility to know their limits and take care not to exceed them- I couldn’t help but feel that the article lacked an explanation as to how ethanol affects us in a purely biological sense. Whether we can detach this from the social factors affecting our behaviour is another point entirely; indeed a very interesting one, but some background would have been helpful in determining the validity of Fox’s argument, or making it a balanced argument.

In comes the information imparted to me in a lecture. One of our lecturers was teaching us about a reaction which occurs in the body when we consume alcohol. The ethanol in the alcoholic drinks we consume is oxidised by an enzyme in the liver called alcohol dehydrogenase (a zinc-containing enzyme for anyone who’s interested) to form acetaldehyde (ethanal). This is converted by another enzyme to ethanoic acid, but this second process is very slow and so there is a build up of acetaldehyde in the body. The acetaldehyde reacts with a neurotransmitter called epinephrine, to form a cyclic product, which causes a loss in cognitive coherence, a red face and various other classic signs of being drunk. The loss in cognitive coherence may go some way to explaining the anti-social behaviour displayed by drunk individuals, although it’s still not really an excuse!

Epinephrine and the molecule produced from its reaction with acetaldehyde.

So, there we have a little bit about the science behind inebriation. The exact effects on the brain and behaviour are quite a lot more complicated, and obviously the social implications and expectations do play an important role in how we are affected when we drink. Hopefully this has just provided a little bit more information and some satisfaction to the geeky and interested out there.

Food for thought

This all began as a severe and urgent need to fill my time post finals. Having spent 3 months hunched over a desk revising for and then taking my exams, the end felt overwhelmingly and depressingly empty. I had a week in Oxford with no deadlines, no chemistry to occupy my time. What was I to do? To exacerbate the whole situation, it transpired that my friends who had also finished were going to be away for the weekend and I would be alone for around 48 hours. And it was raining.

Whilst enthusing over a day at The Good Food Show with my mother (more on this later), revelling in freedom and culinary delights, it soon became obvious that my borderline obsession with food would be my saviour. I have always loved food and will happily while away the hours in the kitchen with the sole aim of gaining love and adoration through feeding people. My passion for science has also lead me to skirt around the periphery of the intriguingly titled “Molecular Gastronomy” and one of my friends bought me a book entitled thus for my 21^st birthday. So, with the help of this book, articles from Chemistry World involving food in one way or another and oodles of enthusiasm, the vague idea of a “science food blog thingy” was born. Whilst it is still vague, the general concept is a geeky and terribly indulgent foray into the science of food- why recipes work, new methods, techniques and doctrines, digging deeper into the science behind the articles you read in the news about coffee being heinously bad/ actually quite good for you etc. and any fun facts, ideas or insights I may stumble upon. I’m going to be learning as I go along and will try to be as accurate as I can. Some of my posts may be more gastronomic than scientific, as I am a true foodie and sometimes there doesn’t need to be a great scientific point to relate. A really good dish is allowed to be pure pleasure. But there are so many claims and ideas out there that are packaged and marketed as “science” without being properly explained; so many things that we do to food without thinking about why or how it will benefit the outcome and so many phrases, discoveries and issues hijacked by the media and turned into an impenetrable and often terrifying web of conjecture, speculation and half-truth. If I can help to demystify a few of these, or at least bring them to someone’s attention and show that the science of food is fun, relevant and interesting, then that would be great.

I guess the main aim of this blog is food for thought!