Chemical magic in the mouth

Scientists in Switzerland are reporting that bacteria in the human mouth play a role in creating the distinctive flavors of certain foods. They found that these bacteria actually produce food odors from odorless components of food, allowing people to fully savor fruits and vegetables. Their study is scheduled for the November 12 edition of the ACS bi-weekly Journal of Agricultural and Food Chemistry.

In the study, Christian Starkenmann and colleagues point out that some fruits and vegetables release characteristic odors only after being swallowed. While scientists have previously reported that volatile compounds produced from precursors found in these foods are responsible for this ‘retroaromatic’ effect, the details of this transformation were not understood. To fill that knowledge gap, the scientists performed sensory tests on 30 trained panelists to evaluate the odor intensity of volatile compounds – known as thiols – that are released from odorless sulfur compounds found naturally in grapes, onions, and bell peppers. When given samples of the odorless compounds, it took participants 20 to 30 seconds to perceive the aroma of the thiols – and this perception persisted for three minutes.

Volatile sulfur compounds have a low odor threshold, and their presence at microgram per kilogram levels in fruits and vegetables influences odor quality. Sensory analysis demonstrates that naturally occurring, odorless cysteine-S-conjugates such as S-(R/S)-3-(1-hexanol)-l-cysteine in wine, trans-(+)-S-1-Propenyl-L-cysteine sulfoxide in onion, and S-((R/S)-2-heptyl)-l-cysteine in bell pepper are transformed into volatile thiols in the mouth by microflora. The time delay in smelling these volatile thiols was 20-30 s, and persistent perception of their odor occurred for 3 min. The cysteine-S-conjugates are transformed in free thiol by anaerobes. The mouth acts as a reactor, adding another dimension to odor perception, and saliva modulates flavors by trapping free thiols.

The researchers also determined that the odorless compounds are transformed into the thiols by anaerobic bacteria residing in the mouth – causing the characteristic ‘retroaromatic’ effect. “The mouth acts as a reactor, adding another dimension to odor perceptions,” they explain. However, the authors conclude, it is saliva’s ability to trap these free thiols that helps modulate the long-lasting flavors.

Lithium:The Oil Of The 21st Century

Today, most of our vehicles and electric power plants run on fuels that come from petroleum. The supply of these fuels will end a few decades from now. So what would power our cars and homes? The answer may be lithium.

Oil in the 20th century
Let’s understand the role of oil better in our times. In 1885, Gottlieb Daimler & Wilhelm Maybach invented a car engine that ran efficiently on petrol. This made it cheaper to own and use cars. Soon people around the world were buying cars, trucks. Diesel-run buses and trains ferried thousands of people across hundreds of kilometres. Since everyone needed petrol and diesel, drilling oil wells and extracting petrol became a very big business, employing millions of people. Today, there is no country that can do without oil.

An electronic world
But oil is a limited resource, and it also contributes to global climate change. Hence, countries are looking for other means to produce electricity and run vehicles, which are cheap, eco-friendly and plentiful. Sunlight is one of them, wind another. Hydrogen can be used as a fuel to make electricity. But a new source of energy scientists are thinking of is lithium.

It is already used in lithium ion batteries, the kind that powers your laptops and mobile phones. These batteries are rechargeable, so even a small amount of lithium will go a long way. In the future, you may be driving electric cars powered by lithium ion batteries. The chemical also has special uses in nuclear power plants. As we add more electronic devices in our lives, and reduce oil-burning ones, we’re going to need hundreds of tonnes of it every year.

Getting rich with lithium
In the 20th century, countries that produced oil, like Saudi Arabia, UAE and Russia became very rich, as other countries depended on them for supplies. Similarly, China is getting rich by supplying rare earth minerals to many countries. So in the coming century, countries that have big deposits of lithium can hope to get rich too.

Bolivia holds about half of the world’s potential its supply. Next come Chile, Argentina and China. The Bolivian government has signed deals with countries including Japan, Korea and France to mine and export lithium. It plans to use this money to build hospitals, schools and battery-making factories, helping many millions of Bolivians escape poverty, malnutrition and ill-health. A big source of the metal has also been found in Afghanistan.

And we hope that this year – the international year of chemistry – we’ll come to know of more sources of this important element!

Cobalt Used As Industrial Catalyst

Cobalt(the CAS number is 7440-48-4), a common mineral, holds promise as an industrial catalyst with potential applications in such energy-related technologies such as the production of biofuels and the reduction of carbon dioxide. That is, provided the cobalt is captured in a complex molecule so it mimics the precious metals that normally serve this industrial role.

In work published Nov. 26 in the international edition of the chemistry journal Angewandte Chemie, Los Alamos National Laboratory scientists report the possibility of replacing the normally used noble metal catalysts with cobalt.

Catalysts are the parallel of the Philosopher’s Stone for chemistry. They cannot change lead to gold, but they do transform one chemical substance into another while remaining unchanged themselves. Perhaps the most familiar example of catalysis comes from automobile exhaust systems that change toxic fumes into more benign gases, but catalysts are also integral to thousands of industrial, synthetic, and renewable energy processes where they accelerate or optimize a mind-boggling array of chemical reactions.  It’s not an exaggeration to say that without catalysts, there would be no modern industry.

But a drawback to catalysts is that the most effective ones tend to be literally precious. They are the noble metal elements such as platinum, palladium, rhodium, and ruthenium, which are a prohibitively expensive resource when required in large quantities. In the absence of a genuine Philosopher’s Stone, they could also become increasingly expensive as industrial applications increase worldwide. A push in sustainable chemistry has been to develop alternatives to the precious metal catalysts by using relatively inexpensive, earth-abundant metals.

Cobalt, like iron and other transition metals in the Periodic Table, is cheap and relatively abundant, but it has a propensity to undergo irreversible reactions rather than emerging unchanged from chemical reactions as is required of an effective catalyst. The breakthrough by the Los Alamos team was to capture the cobalt atom in a complex molecule in such a way that it can mimic the reactivity of precious metal catalysts, and do so in a wide range of circumstances.

The findings of the Los Alamos team have major ramifications and suggest that cobalt complexes are rich with possibility for future catalyst development. Due to the high performance and low cost of the metal, the cobalt catalyst has potential applications in energy-related technologies such as the production of biofuels, and the reduction of carbon dioxide. It also has implications for organic chemistry, where hydrogenation is a commonly practiced catalytic reaction that produces important industrial chemical precursors.

Benzene and Its Alternative Solvents

A solvent is a liquid, solid, or gas used to dissolve another solid, liquid, or gaseous solute for making a solution.  Benzene, as a chemical that is formed as a result of incompletely burned natural products, is a non-polar solvent used in the manufacture of such products as polymers and plastics, phenol for resins and adhesives, rubber, lubricants, dyes, detergents, drugs, explosives, napalm, and pesticides. According to the Occupational Safety & Health Administration, it is a carcinogen.

Main Uses
Until it was classified a carcinogen, benzene was added to gasoline to boost its octane rating and reduce knocking. Today, it is primarily used as an intermediate in the production of styrene (used to make polymers and plastics), cumene (used to make phenol for adhesives) and cyclohexane (used to make nylon). Toluene, which is less hazardous, is now commonly used as a solvent in chemical reactions instead of benzene.

Exposure
It is toxic. Exposure to benzene can cause serious problems by damaging your DNA. High levels can result in benzene poisoning. Symptoms include headaches, dizziness, confusion, drowsiness, tremors and unconsciousness. At extremely high levels it can result in death. Long-term complications, in addition to cancer, can include excessive bleeding and anemia due to its effect on the bone marrow and blood.

Alternative Solvents
Cyclohexane
is a colorless flammable liquid. It is a non-polar solvent like benzene, which means it is insoluble in water and soluble in non-polar substances such as alcohol, ether, acetone, benzene and ligroin. It is manufactured by reacting benzene with hydrogen. It is a major raw material for producing adipic acid and caprolactum. Cyclohexane is also used in electroplating, rubber manufacturing, and in the production of varnish solvents.

Toluene is a clear, water-insoluble non-organic solvent with the typical smell of a paint thinner. It is capable of dissolving a number of inorganic chemicals such as sulfur and occurs naturally as a component of crude oil. It is commercially produced in petroleum refining because it is a major constituent of gasoline. 

How do smoke detectors work?

As the saying goes, “Where there’s smoke, there’s fire.” Smoke detectors are amazing: They’re pretty inexpensive, but they save thousands of lives each year. All smoke detectors consist of two basic parts: a sensor to sense the smoke and a very loud electronic horn to wake people up. Smoke detectors can run off of a 9-volt battery or 120-volt house current. There are two most common types of smoke detectors used today: photoelectric detectors and ionization detectors.

Photoelectric Detectors
You may have noticed sometimes when you walk into a mall or store , a bell goes off as you cross the threshold. If you look, you will often notice that a photo beam detector is being used. Near the door on one side of the store is a light (either a white light and a lens or a low-power laser), and on the other side is a photodetector that can “see” the light.

When you cross the beam of light, you block it. The photodetector senses the lack of light and triggers a bell. You can imagine how this same type of sensor could act as a smoke detector. If it ever got smoky enough in the store to block the light beam sufficiently, the bell would go off. But there are two problems here:

1.It’s a pretty big smoke detector.

2.It is not very sensitive.

There would have to be a LOT of smoke before the alarm would go off — the smoke would have to be thick enough to completely block out the light. It takes quite a bit of smoke to do that.

Photoelectric smoke detectors therefore use light in a different way. Inside the smoke detector there is a light and a sensor, but they are positioned at 90-degree angles to one another.

In the normal case, the light from the light source on the left shoots straight across and misses the sensor. When smoke enters the chamber, however, the smoke particles scatter the light and some amount of light hits the sensor: The sensor then sets off the horn in the smoke detector.Photoelectric detectors are better at sensing smoky fires, such as a smoldering mattress.

Ionization Detectors
Ionization smoke detectors use an ionization chamber and a source of ionizing radiation to detect smoke. Inside the ionization detector is a small amount (perhaps 1/5000th of a gram) of americium-241(CAS number is 7440-35-9), a radio active material.

This type of smoke detector is more common because it is inexpensive and better at detecting the smaller amounts of smoke produced by flaming fires.

Stopping mineral processing from turning to jelly

Cooking minerals in huge mixing tanks can turn them to jelly, and an Adelaide researcher has found out why. The work could save the industry millions of dollars a year in lost production and cleaning costs.

Sticky gel-like materials form during the liquid processing of mineral ores, when clays present in the deposits release elements such as silicon and aluminium into the liquid under particular conditions of temperature and acidity. That’s what Dr Ataollah Nosrati, a research associate at the Ian Wark Research Institute (The Wark) of the University of South Australia has found.

To extract valuable metals, some of world’s largest mineral deposits are mined and processed as concentrated slurries. This generally occurs in mixing tanks at high temperatures under aggressive acidic or alkaline conditions. Zinc silicate ores, for instance, are typically cooked at between 50 °C and 80 °C under very acidic conditions for a couple of hours.

But occasionally, the breakdown of the attached silicon compounds results in everything thickening into a gel. This kind of thing can also happen with other ores containing reactive clays or silicates.

“If we can prevent or mitigate this,” Ataollah says, “it would lead to a higher recovery rate of valuable metals, lower operating costs, and a dramatic increase in throughput with a greatly reduced number of plant shutdowns. The decreased need for cleaning the mixing tanks would also increase safety.”

“Ataollah identified and established plausible mechanisms responsible for gelation,” said Prof Jonas Addai-Mensah, Associate Director (Minerals) at The Wark. “He also proposed possible mitigation strategies in actual mineral plants for this costly and intractable issue.”

Due to their high solubility at elevated temperatures under acidic conditions, the clay-based minerals release significant amounts of gel-forming elements into the processing solution, Ataollah found. Reactions among these elements can have a significant impact on the particle interactions and flow behaviour in the solution, and that is what leads to gelling.

The research findings pave the way for enhancing our ability to process complex, low-grade ores of copper, gold, nickel and cobalt which contain silicates and aluminosilicate clays.

Ataollah Nosrati is one of 12 early-career scientists unveiling their research to the public for the first time thanks to Fresh Science, a national program sponsored by the Australian Government.

What Are the Benefits of Diosmin?

Diosmin is a natural flavonoid that is extracted from various plant sources and sold as a daily supplement either by itself or combined with similar flavonoids. People use this chemical to make medicine.

Diosmin might help treat hemorrhoids by reducing swelling (inflammation), and restoring normal vein function. It is used for treating various disorders of blood vessels including hemorrhoids, varicose veins, poor circulation in the legs (venous stasis), and bleeding (hemorrhage) in the eye or gums. It is also used to treat swelling of the arms (lymphedema) following breast cancer surgery, and to protect against liver toxicity. It is often taken in combination with hesperidin, another plant chemical.

Companies throughout the world offer diosmin in pill form. According to some experts, diosmin is often combined with a similar compound called hesperidin to maximize its effects.

Diosmin improves blood circulation and strengthens vein walls by improving the elasticity of blood vessels while inhibiting certain pro-inflammatory lipids. It helps your blood to flow against gravity and return from your legs to your heart. This has the effect of reducing or eliminating varicose and spider veins, while preventing recurrence by treating their cause.

Citrus fruits, especially lemons, are rich sources of diosmin, according to “Food Chemistry.” Lemons produce a number of useful flavonoids, including diosmin, in both the mature fruit and the leaves. Buddha’s finger, a type of citron, is also rich in diosmin. According to the “Journal of Agricultural and Food Chemistry,” green Meyer lemons and Buddha’s finger fruits contain the highest diosmin levels, especially when treated with hormones during the early growth stages.

The relief that diosmin offers from poor circulation, varicose and spider veins, and hemorrhoids can enable you to enjoy more physical activity and less interruptions in your social life.  It does cause some side effects, including digestive discomfort and headache. More time can be spent with family and friends, enjoying your favorite activities without the discomfort caused by poor circulation.

Have A Nice Cup Of Tea

Tea is the most famous beverage enjoyed by almost every person in the entire world. Each morning as we wake up, we need our perfect cup of tea. Almost every part of the world has people enjoying their perfect cuppa of tea. Have you ever thought when and how did this tea evolve?

Know Its Origin
Around 4000 years ago, it is said that people in China first started drinking tea. Then after 300 years ago, tea was introduced in Europe. After this, tea became popular in countries like North America and Europe around the 18th century. And China was the only country selling tea to other countries. In this way, China’s tea business started soaring.

Countries like Sumatra, Java and Formosa also started growing tea plantations. It was later discovered that the tea plants grew only up to one metre in China, whereas in India the plants grew up over six metres in height in India. Tea business now shifted to India.

How is Tea processed?
The leaves and small buds are plucked from the tea plantations. The tea plant needs to be at least three years old for the leaves to be plucked. We find two types of tea leaves, green and black. The plucked leaves and buds are pressed, dried and packed.

In order to prepare black tea, the leaves are pressed between the rollers and are left for fermentation. Once the leaves are fermented, again they are pressed between the rollers and are kept in hot rooms in order to dry.

Later the leaves are packed and sent to the desired places. Here is a video to help you understand the entire process of how tea is made.

Benefits of tea
Tea helps in preventing blood clotting in our body; it helps in lowering the cholesterol levels and also deactivates cancer promoters. Tea also contains natural fluoride that helps in maintaining the bones and teeth.

Known as the “wonder drink”, tea is packed with nutrients that are essential for our health. Tea is known to have certain polyphenols, natural organic chemicals that offers many benefits to our health.

In 1989, a study conducted by the Japanese Journal of Nutrition revealed that tea producing regions had a lower stomach cancer mortality rate as compared to non-tea producing regions.

In short, tea is anytime better compared to coffee and it will help you reap many benefits as compared to any other drink.

Interesting Facts About Pencils

There is no doubt that pencils have made a mark in our thoughts and dreams. Children all over the world learn the simple facts using the humble pencil. Several masterpieces of art have been created using these sleek materials.

The Latin word for pencil is penillus which means a painter’s brush. The early pencils were actually brushes that used to resemble today’s pencil.

Pencils are used for writing and made from the mineral graphite and clay. The mineral graphite also belongs to the carbon family. The original form of pencil dates back to somewhere before 1565 in ancient Rome. The Romans used to write using a thick stylus like instrument made of the metal lead. The metal lead hails from the family of carbon. It is a soft and flexible metal among all the other metals. They used this stylus to leave a readable mark on papyrus which was an early form of paper.

In 1564, a huge graphite deposit was found in England and it was discovered that this particular mineral left dark mark as compared to the conventional lead. People started writing by wrapping these graphite pieces in a string for a firm grip. Later, the graphite pieces started to be inserted in hollow wooden sticks. This marked the official birth of a wood cased pencil! The pencil was a perfect example of fine craftsmanship and artistry at this point of time.

Evolutions happen in every aspect of life. So it did happen for our dear pencil as well. In the year 1662, Nuremberg, a place in Germany mass-produced the pencils for the first time. Post this period, lot of machines was invented to make the job easily and perfect.

The wood is milled; six half circle grooves are cut in order to insert the graphite lead. Once the graphite lead is inserted two grooves are glued together to encase the graphite lead. Once the glue dries, a special machine is used to give a perfect shape to the pencil. Once the pencil gets its right shape, it is painted and graded.

The wood that encases the pencil needs to be soft to help in easy sharpening. So, people started using the red cedar wood(Cedarwood Oil), which is known as the softest wood. It may sound quite simple to read; however there are in all 125 steps that one needs to follow in a pencil making company for each pencil that somebody manufactures.

To sum up, there is an interesting fact about pencils. Did you know that pencils cannot be used in space? NASA spent lot of time looking for a writing material to be used in space. It was found that pen uses gravity to write. However, when we write with pencils, the fine particles from graphite dust come out and would start floating around in the cabin posing a health threat to the astronauts. 

What Is Teflon?

You go shopping with your mother for a non-stick pan! Your mother plans to prepare some pan cakes and you watch her prepare it for you. You anticipate that the dough when poured on the pan is sure to stick and your mother is going to have a hard time taking it out.

However, when your mother pours the dough, to your surprise the pan cake comes out clean without even a piece sticking to the pan. You wonder if this is some kind of magic! This is definitely the magic of Teflon!There is a coating on the surface of every non-stick pan. It is called as Teflon. This coating prevents the food from sticking to the utensil.

What is Teflon?
Teflon was invented in the year 1938 by Dr. Roy Plunkett at DuPont’s Jackson Laboratory while trying to invent a new refrigerant. During the experience, Dr Roy Plunkett happened to create a compound that gas polymerized while it was stored. What came out was a solid, waxy and super slippery substance.

Dupont Laboratory got a patent for this substance in the year 1940. However, they did not use it till 1950s. Post that, the coating was used on cookware and soon the products improved and today they are more durable as compared to any other cookware.

It is a substance called as polytetrafluoroethylene (PTFE). This is considered as the most slippery substance that ever exists. Teflon is a fluroplastic that is odourless and colourless powder with many properties that will give you many uses.

How is Teflon coating done?
Teflon is applied to the pots and pans in a multi-step process to make sure that the material sticks to the surface of the utensil. The first layer is a sticky molecule that is applied to the surface of the utensil. This is followed by the application of a non-stick surface and is followed by a final coating of non-stick Teflon and a combination of other hardeners.

Teflon being an inert substance is considered safe for cooking. Teflon coated products have made cooking easier and less messier as compared to earlier times.

While cooking on a PTFE coated utensil, here are some things you need to remember. Always use plastic or wood utensils on Teflon coated cookware as metal stirrers will scrape away the Teflon coating and harmful fumes may arise from the scratched area as you cook on fire.

While washing Teflon cookware use only soft sponges or brushes with soft bristles to avoid scratches. In case there is burnt food that is stuck to the utensil, loosen them by soaking the utensil in water overnight instead of trying to scrub them out.

Avoid leaving Teflon coated utensil unattended on a flame as too much of heat can lead to melting of the coating and the fumes may prove harmful to our health. Wash Teflon coated utensils by hand and avoid putting them in the dishwasher as this can spoil the coating on the utensil.