Category Archives: Chemistry

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Simple way of cooking rice could halve its calories

I know, the title sounds like one of those scams that promise you’ll lose weight – but this is all science all the way. Researchers in Sri Lanka have found a simple way of cooking the rice that not only reduces calories by half, but also provides other health benefits. The key addition is coconut oil.

Image via MorgueFile.

 

 

Rice is not only the fuel that powers millions of students around the world (alongside instant noodles), it’s a staple in numerous cuisines around the world. But as cheap and delicious as it is, there’s one major problem associated with rice – it’s not good for you. It’s not that it’s necessarily bad for you, but rice has many calories – according to Science Alert, one cup of cooked rice contains around 240 starchy calories – nasty carbohydrates that can quickly turn to fat if you don’t burn them off.

According to the researchers, all you need to do is add some coconut oil in the water you boil the rice in – some 3% of the rice quantity. So if you want to boil half a kg of rice (about 1 pound), all you need to do is add 15 grams of coconut oil (about one teaspoon).

Undergrad student Sudhair James conducted the research with his supervisor and presented the results at the National Meeting and Exposition of the American Chemical Society on Monday.

“After it was ready, we let it cool in the refrigerator for about 12 hours. That’s it,” James told Roberto A. Ferdman from The Washington Post. To eat it, you simply pop it in the microwave and, voila, you have a “fluffy white rice” that’s significantly better for you.

The process is extremely simply to make, but it actually involves some pretty interesting biochemistry. Rice contains a lot of starch; there are actually two main starches (polysaccharides): amylose and amylopectin. Amylose has a branched out structure and therefore has more surface area, which makes it easily digestible. But on the other hand, amylopectin is harder to digest; it passes through the large intestine, where they act like a fiber and provide numerous benefits. Most of the starchy foods contain these hard to digest starch, but when you cook them, they usually turn into more digestible versions of starch.

Image via Imgur.com

 

Sudhair wanted to investigate this issue and see how rice can be cooked so that it maintains the more healthy starch; he and his supervisor cooked it in 38 different ways, and they obtained the best results with coconut oil. A previous study also showed that letting pasta cool down before reheating it increased the content of resistant starch content, so they also tried that.

“Cooling for 12 hours will lead to formation of hydrogen bonds between the amylose molecules outside the rice grains which also turns it into a resistant starch,” explained James in a press release. And he notes that heating the rice back up afterwards doesn’t change the resistant starch levels.

If their results are confirmed by other studies, this might lead to a new generation of packaged rice – pre-cooked in coconut oil and then cooled down. But this might have even bigger implications – could this technique be applied to other foods? Could all our favorite starchy foods (like french fries or bread) become healthier? Could other substances (potentially cheaper and more accessible) be used instead of coconut oil? Those are the hot questions right now.

“It’s about more than rice,” Thavarajah said. “I mean, can we do the same thing for bread? That’s the real question here.”

As a rice fan, this is extremely exciting – and it could bring with it a major health and dietary revolution. I’m really looking forward to it.

 

In square ice (left) water molecules are locked at a right angle. This looks nothing like the familiar hexagonal ice (right).

Sandwiching water between graphene makes square ice crystals at room temperature

In a most unexpected find, the same  University of Manchester team that isolated graphene for the first time in 2003 found that water flattens into square crystals – a never encountered lattice configuration – when squeezed between two layers of graphene. The square ice qualifies as a new crystalline phase of ice, joining 17 others previously discovered. The finding could potentially improve  filtration, distillation and desalination processes.

Water, don’t be square

In square ice (left) water molecules are locked at a right angle. This looks nothing like the familiar hexagonal ice (right).

Previously, Andre Geim of the University of Manchester, UK – who shared a Nobel Prize in physics in 2010 for his groundbreaking graphene research – was left scratching his head after he found water vapours could pass through laminated sheets of graphene oxide. This was peculiar since helium couldn’t do this, a molecule that’s a lot smaller than water. To complicate the puzzle, liquid water – which is more tightly bonded than vapor – could also pass through the graphene oxide.

Then, simulations showed that water was forming square ice crystals between the graphene sheets. “But you never trust molecular-dynamics simulations,” says Geim. The team thus proceeded with a simple experiment. They dropped just one milliliter of water on a sheet of graphene (an one atom thick layer carbon arranged in a hexagon lattice), then placed a second one on top. As the water slowly evaporated, it was reduced to an one atom thick layer (just like the graphene!), all arranged in a square lattice at room temperature.

This electron scan microscope image clearly shows how the square ice looks like. Image: NATURE

In normal conditions (temperature and pressure), the water molecule has a V shape, with the two hydrogen atoms bonded to the oxygen atom at a 105° angle. Imagine Mickey Mouse, that’s water! In ice form,  four bonds are usually arranged in a tetrahedral (pyramid) shape. In the square ice, however, all the atoms line up with a right angle between each oxygen–hydrogen bond.

After several iterations of the experiment, Geim’s team ended up with one, two or three atom thick layers of square ice crystals, all aligned one atop another. Remember, I mentioned the water molecules were squeezed by the graphene. In fact, the pressure exerted by the two layers could be more than 10,000 times that of  atmospheric pressure, according to the paper published in Nature. This happens because as the graphene sheets get closer, they distort each others’ electron cloud. The sheets are attracted to one another by a huge intermolecular force known as the van der Waals force, like “having millions of little springs holding them together,” according to Alan Soper, a physicist at the Rutherford Appleton Laboratory in Harwell, UK.

This might not be some queer finding confined to a laboratory setting. Square ice might be encountered in nature where enormous pressure is exerted over tight quarters. It just may be that we haven’t found it yet. On a practical level, the square ice method might  improve desalination filters based on graphene.

“Finding out how the water behaves in a capillary is a big part of what we need to do to make a good filter,” says Geim. “This is a very important step.”

 

molecule printer

This 3D printer for small molecules might change organic chemistry forever

At his lab at the University of Illinois at Urbana-Champaign, Dr. Martin Burke laid the foundation for what he simply calls “The Machine” – an automated small molecule synthesizer that’s set to change the way chemists assemble chemicals forever. It’s like a 3D printer, only for molecules. Starting with some basic chemicals, which Burke and colleagues separate into blocks, the machine assembles all sorts of molecules in a modular fashion, like pinning Lego bricks. Hours and hours of toiling in the lab might now be dedicated to more important business, and molecules yet to be synthesized can now be attempted. These small molecules hold tremendous potential in medicine, but technology is also sure to exploit the machine – anything from LEDs to solar cells.

The machine that builds molecules

Credit: Burke, Science

Small molecules and polymers are common components in medicine, food, cosmetics, pesticides, narcotics and research reagents. They can also be found in the human body and in the environment.Small, chemically manufactured molecules (or SMOLs for short) are the classic active substances and still make up over 90 percent of the drugs on the market today. One example is acetylsalicylic acid (ASA), aspirin’s active ingredient with a molecular weight of about 180 g/mol. These small molecules can be processed into easily ingestible tablets or capsules. If the tablet dissolves in the gastrointestinal tract, the dissolved active substance is absorbed into the bloodstream via the intestinal wall. From there, the small molecules can reach almost any desired destination in the body because of their tiny size. Their small structure and chemical composition often also helps them to easily penetrate cell membranes.

Credit: Burke, Science

At the same time, these small small molecules are also very difficult to synthesize. You need a lot of time, going from reaction to reaction which often can involve hundreds of steps and, usually, highly trained personnel is required. The Machine is different. It does all the dirty work for you, providing it has the process uploaded in its software, and almost anyone can do it – even chemistry neophytes.

“A lot of great medicines have not been discovered yet because of this synthesis bottleneck,” he says. With his new technology, Burke aims to change that. “The vision is that anybody could go to a website, pick the building blocks they want, instruct their assembly through the web, and the small molecules would get synthesized and shipped,” Burke says. “We’re not there yet, but we now have an actionable roadmap toward on-demand small-molecule synthesis for non-specialists.”

Nature is very good at building small molecules, but so far chemists’ efforts aimed at mimicking these processes have proven slow or, more often than not, impossible with current tech. Plants, animals, and microbes manufacture many small molecules with protein-like functions, and with some precise chemical modifications. The machine could assemble these sort of small molecules without the need for proteins.

Credit: Burke, Science

First the machine breaks down very complex molecules into their basic chemical building blocks then induces a chemical reaction and washes away the reaction’s byproducts—slowly building each molecule from the ground up. Using this process the machine can utilize over 200 different building blocks along with thousands of other molecules to ‘print’ billions of different organic compounds, many of which make up 14 classes of small molecules, including the ratanhine molecule family.

“Doing real atomistic modifications to transform nature’s starting points into actual medicines is really, really challenging. The slow step in most cases in the synthesis. As a result, many natural products don’t get worked on in any practical way.”

“Nature makes most small molecules the same way,” Burke says. “There are a small number of building blocks that are coupled together over and over again, using the same kind of chemistry in an iterative fashion.” That means small molecules are inherently modular. So when Burke’s team analyzed the chemical structures of thousands of different natural products, patterns emerged. “There are building blocks that appear over and over again, and we’ve been able to dissect out the building blocks that are most common,” he says.

Burke has now founded a company called Revolution Medicines to further scale his project and receive funding. The company already is working to improve upon an anti-fungal compound known as Amphotericin B, which is found in nature and used to treat patients with life-threatening fungal infections. Check out this awesome interview with Dr. Burke below.

“Perhaps most exciting, this work has opened up an actionable road map to a general and automated way to make most small molecules,” stated Burke. “If that goal can be realized, it will help shift the bottleneck from synthesis to function and bring the power of making small molecules to nonspecialists….A 3D printer for molecules could allow us to harness all the creativity, innovation, and outside-the-box thinking that comes when non-experts start to use technology that used to only be in the hands of a select few.”


The molecules the Illinois team synthesized, as well as the machine itself, were described in a paper published in Science.

Left: Van Gogh painting “Wheat Stack under a Cloudy Sky” (Kröller-Müller Museum, Netherlands). The paint sample area is indicated by a white circle. Upper right: Detail of the painting in the sample area, lower right: Detail of the paint sample (picture: Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)

Why Van Gogh’s paintings are fading to white

Belgian scientists have revealed a refined explanation for the chemical process that’s currently degrading Vincent van Gogh’s famous paintings, which are losing their bright red. Like other old paintings, van Gogh’s works are losing their saturated hue because of the interaction between red led and light. Using sophisticated  X-ray crystallographic methods, the researchers identified a key carbon mineral called plumbonacrite in one of his paintings, which explains the process even better.

Left: Van Gogh painting “Wheat Stack under a Cloudy Sky” (Kröller-Müller Museum, Netherlands). The paint sample area is indicated by a white circle. Upper right: Detail of the painting in the sample area, lower right: Detail of the paint sample (picture: Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)

All paints are made up of three key parts: the vehicle (usually water), the pigment (the stuff that gives matter color – usually mined from the earth in the form of clay or mineral or even plants, but also synthetic form), and a binder (otherwise you’d just have colored water – typically chalk is used). Red lead (minium, or lead (II,IV) oxide) is a lead oxide whose composition is Pb3O4 and whose color varies over time. It’s been a favorite pigment for thousands of years. In fact, it can still be found in the old cave paintings some 40,000 years old. Of course, it degrades over time darkening as the red lead pigment is converted to plattnerite (beta-lead dioxide) or galena (lead sulfide). At other times, the color will lighten or bleach due to the conversion of red lead to lead sulfate or lead carbonate.

A team led by Koen Janssens at the University of Antwerp investigated what makes van Gogh’s paintings turn white by taking a microscopic sample from “Wheat Stack under a Cloudy Sky”, one of his famous work, and subjecting it to crystallographic analysis. X-ray powder diffraction mapping and tomography techniques were employed to determine the spatial distribution of the various crystalline compounds found throughout the sample. They eventually found an unexpected compound, the very rare lead carbonate mineral called plumbonacrite (3 PbCO3·Pb(OH)2·PbO).

“This is the first time that this substance has been found in a painting from before the mid twentieth century,” reports Frederik Vanmeert, first author of the paper. “Our discovery sheds new light on the bleaching process of red lead.”

Considering this latest finding, the Belgian researchers proposed a chemical reaction pathway of the red lead under the influence of light and CO2, which ultimately altered the pigment and caused a color change in the painting. As light hits the paint (red lead and other pigments), the incoming energy causes electrons to move from the valance band to the conducting band in red lead, which is a semi-conductor. This reduces the red lead to PbO, which reacts with other products formed by the reaction of CO2 from the air with the degrading binding medium. Ultimately, this forms plumbonacrite  as an intermediate that is converted to hydrocerussite and then to cerussite (lead carbonate). All these products are white, hence the lower saturation. The findings were reported in  Angewandte Chemie.

Art aficionados shouldn’t fret too hard, though. Van Gogh’s paintings are still marvelous, despite more than a hundred years since the Dutch painter made his first stroke on the canvas. Museums give great care and employ special conservation methods to keep the old masters’ work bright and vibrant for hundreds of years to come.

beer4

Scientists taste 170 year old shipwrecked beer

Scientists in Finland have been keeping themselves busy testing two different beers… for science, of course. These are not just your average beers though – they’re almost two centuries old, recovered by divers exploring a 1840s shipwreck in the Baltic Sea back in 2010.

Old Beers

All image credits: Londesborough et al, 2015.

 

When the divers brought the bottles to the surface, due to the change in pressure and temperature, one of the bottles broke, so they did what every responsible adult would have done – they tasted it. However, much to their disappointment, it didn’t really taste like anything, so they did the second thing rational adults would do – they turned the beers in, giving them to scientists, for [ahem] proper research.

When our senses fail, we have machines, and that’s what chemists at the VTT Technical Research Centre of Finland used to sample the beers (called A56 and C49, for some reason which eludes me). Unfortunately, the initial studies confirmed what the divers found – the seawater destroyed the beer’s taste, and gave it a foul odor.

“Bubbles of gas, presumably CO2, formed during sampling, producing a light foam. Both beers were bright golden yellow, with little haze. Both beers smelt of autolyzed yeast, dimethyl sulfide, Bakelite, burnt rubber, over-ripe cheese, and goat, with phenolic and sulfury notes, the researchers wrote.

The 170-year-old beer.

But they also noticed some other interesting features – the overall shape and detail bottles indicate a high quality technology that was only used in Germany and Northern Europe (but not in Finland) for a few decades, so the list of potential producers has been narrowed down significantly. The also found different hop quantities in the two beers, something which can’t be explained by natural processes or seawater dilution – so we’re dealing with two different types of beer here.

Sour Beer – Rosy or with Green Tea

Both beers, when they were fresh, were much more sour than today’s beers. It wasn’t until the late 19th century that brewers learned how to keep acid-producing bacteria out of beer. Until that breakthrough, pretty much all beer, including A56 and C49, was sour beer. An analysis of yeast-derived flavor compounds (yeast basically gives beer its taste and flavor) showed rose and sweet apples flavors that were high in A56. C49 had a higher concentration of flavor compounds for green tea.
“Both beers were acidic, with pH about 1 unit below modern values,” the researchers wrote. “The color strengths were in the range of modern ales and lagers, and much lower than porters or stouts.”
Overall, the two beers probably tasted very differently one from the other.
“In summary, these two, about 170-year-old bottles contained two different beers, one more strongly hopped than the other with the low α-acid yielding hop varieties common in the 19th century.”

They Lied to Us…

Now that the chemistry of the beers has been uncovered, the next step is, of course, to recreate the beer… but the scientists lied to us!

We first covered this story back in 2013, when the beers were first turned in for analysis, and guess what – the team said the beer will likely go into production in 2014.

“The findings belong to the Government of Åland, an autonomous region of Finland (who also funded the salvage), and the Stallhagen brewery of Åland will now use the recipe to produce the beer – with the biggest part of the profits going to charity, which include marine archaeological work and environmental measures to improve the water quality of the seas”, we wrote in 2013.

Well, it’s 2015, and no one has recreated a modern version of the beers. Oh well, one can only hope that we’ll soon get to taste them… let’s drink to that.

Read the full scientific article here, for free.

Image Credit: Pixshark

What makes indian cuisine so special – a molecular explanation

After they analyzed more than 2,000 traditional Indian recipes down to the molecular levels, scientists now think they know what makes Indian cuisine so appealing. Unlike western dishes, Indian recipes are based on ingredients whose flavors don’t overlap, for a unique taste that dumbstrucks anyone who tries it for the first time.

Image Credit: Pixshark

Many who try Indian food never look back, and it’s easy to understand why. It’s seductively delicious because of a unique approach to flavoring. On average, a traditional Indian dish has at least seven ingredients that often have various flavors and/or spicings that are heterogeneously combined, so that each bite or mouthful can reveal different combinations of flavor elements that burst upon the tongue at different times in the chewing process.

Let’s take a moment to understand how flavors work their magic, first. Flavor is a sensory impression the brain registers when our chemical sensors (taste and smell) interact with substances (food). Of the chemical senses, by far the most important is smell. Taste is limited to sweet, sour, bitter, salty, umami, and other basic tastes, but as previously reported the odors of food can be limitless in combinations. To make food taste interesting or avoid making it taste awful, chefs advise you use ingredients which have the right amount of flavor compounds (specific chemicals) in common. Chocolate and blue cheese might sound like a bad idea, but if mixed well to share the optimum amount of flavor compounds, it’ll taste great.

Indian cooks know spices. They use a large amount of a large variety of spices and their cooking techniques maximize the flavor in the final product. A skilled Indian cook uses spices like a painter who uses colors that they have grown to be very comfortable with. Image: Malabar Spice

On average, there are just over 50 flavor compounds in each food ingredient and this interactive chart made by Scientific American will show you which ingredients mix well together, according to Western cuisine by overlapping flavors. Roasted beef works good with coffee or caviar. In fact, roasted beef seems to work well with anything. Asian cooking,however, is different – it works with congruous ingredients.

Researchers at the Indian Institute for Technology in Jodhpur scrapped thousands of recipes from a popular website, broke each to its constituent ingredients, then by flavors for each item. They found that rarely do the dishes share common flavors. Here’s an example for a random recipe.

Each ingredient has its own flavor makeup which can be dozens in number. Coconut and onions don’t mix, as we all know, but some chemicals inside do.

So any two ingredients can pair up.

Ultimately, some 200 ingredients were mapped in their database. What they found is that  Indian cuisine tended to mix ingredients whose flavors don’t overlap at all.

“We found that average flavor sharing in Indian cuisine was significantly lesser than expected,” the researchers wrote in Nature.

What’s interesting is that this trend is intensified when certain spices are used. A prime example is  cayenne, a basis for curry. When cayenne is added to dishes, the researchers found that these are likely to use ingredients with less flavors in common. In similar vein are green bell pepper, coriander and garam masala.

So, what you might want to do next time you’re making dinner is be a bit creative. Don’t get sidetracked by seemingly incongrous ingredients. Work it out. Who knows what you’ll invent. And don’t be afraid of curry. Bon Appétit!

Spider venom may be crucial in alleviating chronic pain - something which affects 20% of all people. Image via Wiki Commons.

Spider Venom May Hold Key to New Generation of Painkillers

Scientists undertook the gargantuan task of analyzing the compound chemicals found in the venom of 206 spiders, and they discovered what may lead to a new generation of painkillers, improving the lives of over 1 billion people.

Spider venom may be crucial in alleviating chronic pain – something which affects 20% of all people. Image via Wiki Commons.

While humans are hard-wired to avoid potentially venomous creatures like snakes or spiders – they may actually be the key to alleviating serious pains. A team of Australian researchers has discovered 7 compounds that have a high therapeutic potential in dealing with chronic pain.

“A compound that blocks Nav1.7 channels is of particular interest,” said Glenn King, who led the study at Australia’s University of Queensland.

The key here lies in the so-called  Nav1.7 channel, which is associated with pain and inflammation in humans. Nav1.7 is a sodium ion channel that in humans usually expressed at high levels in pain neurons. If the Nav1.7 channel can be blocked, then the unpleasant sensations caused by pain and inflammation can be stopped.

“A compound that blocks Nav1.7 channels is of particular interest for us,” Professor Glenn King of the University of Queensland’s Institute for Molecular Bioscience, an author of the study, said in a press release. “Previous research shows indifference to pain among people who lack Nav1.7 channels due to a naturally-occurring genetic mutation — so blocking these channels has the potential of turning off pain in people with normal pain pathways.”

Chronic pain is a major problem worldwide. About one in five people globally suffer from chronic pain – their life quality drastically reduced; this also carries a huge economic burden – with chronic pain causing losses of over $600 billion in the US alone – more than the economic costs of cancer, diabetes, and stroke combined. Finding a way to alleviate this problem would be a huge deal.

So what makes spider venom so special? Well, there is an estimate of 45,000 species worldwide, many of which are venomous, and quite a few of these venomous ones block nerve activity. For all this stunning biodiversity and this myriad of chemical compounds… we haven’t really studied them all that much. Many secrets still lie hidden in the spiders’ venom – and this may be one of them.

“A conservative estimate indicates that there are nine million spider-venom peptides, and only 0.01% of this vast pharmacological landscape has been explored so far,” Dr. Julie Kaae Klint, an author of the study, said in the press release.

Still, that’s not to say that spider venom hasn’t been studied at all for its therapeutic potential – just that it’s understudied. For example, in 2012 researchers dug into its potential use to treat muscular dystrophy… but from what I could find, nothing has been developed ever since. Even with this research, while it shows great promise in dealing with chronic pain, it will still be a couple few years before we actually see this tested in a clinical setting. But it’s a great reminder that natural chemistry still has a lot of secrets for us – secrets still awaiting to be discovered, if we don’t destroy them.

“Untapping this natural source of new medicines brings a distinct hope of accelerating the development of a new class of painkillers that can help people who suffer from chronic pain that cannot be treated with current treatment options,” Klint said in the press release.

The findings were published in the British Journal of Pharmacology