Hmm, that smells good! We often get to smell fragrance in our daily lives, whether it is from our foods, from the perfume, from the air refresher, so on and so forth. However, these pleasant smell does not came by nature, it was a chemical compound known as ESTER that produce these fragrant. Today, we are going to look at how esters are produced and what are the pros and cons!  

Do you know FLAVOUR ESTER?

Flavour esters are compounds of a great commercial importance due their application. It is used mainly in food and cosmetic industries, but also as environmentally-hazard solvents and intermediates in chemical and pharmaceutical processes. Traditionally, flavourings have been produced by chemical synthesis or extracted from plant materials. Although high costs plus low yields of natural compounds procedure made this technique inadequate at large scale. The examples of flavour esters are isoamyl acetate (banana ) , octyl acetate (orange) , methyl butyrate (pineapple), butyl acetate(apple), methyl trans-cinnamate (strawberry) and so on.

Let’s Look at some FLAVOUR ESTERS!

What is Isoamyl Acetate?

Isoamyl acetate is one of the most important flavour compounds used in food industries because of its characteristic banana flavour. The ester is used as a flavouring compound in many foods and drinks, such as honey, butterscotch, artificial coffee, beverages and perfumes. It is also one of the major flavour components of fermented alcoholic beverages, such as sake, beer and wines.

Here comes another Flavour Esters 

- METHYL BUTYRATE!

What is Methyl Butyrate?

Methyl butyrate (MB) otherwise also known as methyl butanoate methyl ester of butyric acid is an ester which gives a fruity odour of pineapple, apple, and strawberry. The formula of Methyl butyrate is C₅H₁₀O₂ Methyl butyrate can be obtained in small amounts from plant sources. Basically it is produced by distillation of vegetable based essential oils on small scale for utilization as perfumes or food flavours.

Third Example of Flavour Esters !

– OCTYL ACETATE (OA)

What is Octyl Acetate?

Octyl Acetate (OA)  or octyl ethanoate is an organic compound which acts as the flavour ester that is formed from octanol and acetic acid with a fruity orange flavour used in food and beverage industries. The formula of Octyl Acetate is CH₃(CH₂)₇O₂CCH₃.

How are all these flavour esters PRODUCED?

These flavour esters are produced by the acid acid catalyzed reaction which is known as Fischer esterification. When a carboxylic acid reacts with an alcohol, an ester is formed. In addition to an ester being form, water is another product of the reactions. Esterification typically requires a catalyst to speed the reaction. For years concentrated sulfuric acid (H₂SO₄) has been used to do so.

*Sulfuric acid is a very dangerous chemical, which can cause severe chemical burns when in contact with all human tissues. The utmost care needs to be taken when working with sulfuric acid.*

Are esters good for us? Yes or No?

However every flavourings do have side effects which could do harm to our body and isoamyl acetate is no exception from it. The initial signs and symptoms of flavouring-related fixed airways obstruction, including bronchiolitis obliterans, may be subtle. The signs and symptoms seen in affected workers include cough, fatigue, and shortness of breath with exertion. Signs and symptoms generally do not improve on weekends or vacations Signs and symptoms may have a gradual onset, but in some cases severe signs and symptoms have occurred suddenly with rapid progression of lung disease. Bronchiolitis obliterans is a rare and potentially life-threatening form of obstructive lung disease characterized by cough, shortness of breath with exertion, and spirometry findings of fixed airways obstruction.

What is VINEGAR?

Vinegar is a weak acid which consists of acetic acid(CH₃COOH) and water as its main ingredient. Five percent of vinegar is made up of acetic acid which is also commonly known as ethanoic acid. The presence of acetic acid contributes to the sour taste of vinegar. The vinegar chemical formula includes the following elements: hydrogen, carbon, and oxygen. The word vinegar comes from the French 'vin aigre', which means "sour wine." The adding of vinegar into wines is considered an inappropriate combination as it causes the wine to taste like salad dressing. Besides than acetic acid, vinegar contains of tartaric acid, citric acid, and other acids. There are various kinds of vinegar including malt vinegar, wine vinegar, apple cider vinegar, fruit vinegar, balsamic vinegar, rice vinegar, coconut vinegar, palm vinegar, cane vinegar, and raisin vinegar.

How to MAKE vinegar ?

Vinegar is produced by fermenting ethanol which produces acetic acid. Acetobacter aceti, a bacteria which acts as the main cause for conversion of ethanol to acetic acid. When Acetobacter aceti comes into contact with ethanol, acetic acid is produced. Ethanol can be obtained from wine, beer, fermented fruit juice or cider.

SOMETHING you don't know about vinegar!!! 

You'll be impressed at how convenient it is to use vinegar as a household cleaner which is widely available. Vinegar provides assurance in being able to clean the surface, reduce microbes, and by offering an inexpensive and non-toxic alternative to clean your home. 

WHY is vinegar so USEFUL?!

The reason why vinegar is so useful in cleaning is because of its unique properties that contain an acid naturally found in the vinegar at the rate of about 5%, also known as acetic acid. And now, let's see what is acetic acid about.

What you know about ACETIC ACID? 

Acetic acid, CH₃COOH, also known as ethanoic acid, is an organic acid that responsible for the sour taste and pungent smell of vinegar. It is famous for being the primary acid in vinegar. Acetic acid is a weak acid which simply indicates that it is a  partially dissociated acid in an aqueous solution. Pure, water-free acetic acid which is also known as glacial acetic acid is a colourless liquid that absorbs water from the environment (hygroscopy), and freezes at 16.5 °C  to a colourless crystalline solid. When acetic acid is in pure and concentrated form, they are extremely corrosive.

What are the PROPERTIES of acetic acid?

1. Acetic acid has an acidic character

Acetic acid is dissociated to form hydrogen ion (H⁺)  when dissolves in water. It tends to turn blue litmus paper to red proved that acetic acid is acidic in nature. The presence of acidic character in acetic acid is caused by the release of a proton. However, it is a weak acid because it does not dissociate completely in aqueous solution.

2. Acetic acid reacts with sodium bicarbonate

Acetic acid reacts with sodium bicarbonate to produce carbon dioxide.

On passing CO₂ gas through lime water, the lime water turns milky. The milky appearance of lime water is due to the formation of solid calcium carbonate (CaCO₃).

3. Acetic acid reacts with alcohol which is known as esterification

When ethanoic acid reacts with ethanol in the presence of an acid, ethyl ethanoate is formed.

                                                         

How is acetic acid PRODUCED?

1.  Methanol carbonylation

Over the years, most of the acetic acid can be produced by the Monsanto process, in which carbon monoxide reacts with methanol under the influence of a rhodium complex catalyst at 180EC and pressures of 30–40 atm
       

                               CH₃OH + CO → CH₃COOH

2. Acetaldehyde oxidation

Oxidation of Acetaldehyde produces acetic acid. It is also one of most important manufacturing method. The acetaldehyde was produced via oxidation of butane or light naphtha, or alternatively by hydration of ethylene. When butane or light naphtha is heated with air in the presence of various metal ions, including those of manganese, cobalt and chromium; peroxides form and then decompose to produce acetic acid according to the chemical equation.

                                2 CH₃CHO + O₂→ 2 CH₃COOH

3. Oxidative fermentation

On the other hand, acetic acid bacteria of the genus Acetobacter have made acetic acid, in the form of vinegar. These bacteria can produce vinegar by giving them the sufficient oxygen from different type of alcoholic foodstuffs. For example, the most common used feeds are apple cider, wine, and fermented grain. The overall chemical reaction is:

C₂H₅OH + O₂→ CH₃COOH + H₂O

*Industrial vinegar making process are accelerated by improving the supply of oxygen and also keep the surrounding warm to the bacteria.*

4. Anaerobic fermentation

When we comes to anerobic fermentation, we know that it has to deal with the species of anaerobic bacteria, For example, the genus Clostridium or Acetobacterium can convert from sugars to acetic acid, without using ethanol as an intermediate. The overall chemical reaction which is conducted by these bacteria may be represented as:

C₆H₁₂O₆ → 3 CH₃COOH

Conclusion...

Vinegar is a safe, all-natural cleaning product. It doesn't contain harmful toxic chemicals. It is also a natural organic bi-product of fruits, vegetables and grains. It is therefore edible and biodegradable. It is The Perfect Household Cleaner for your family because it is very safe for the environment, for family members, especially those with asthma, and around young children. It is also a very effective and amazingly versatile household cleaner that is inexpensive to use. 

Whether you're lounging on the beach or hiking up a mountain or even you're outside, you're pummelled by invisible rays that can cause your skin to darken and burn. This radiation ultraviolet, or UV can also damage DNA in your skin cells, causing genetic mutations that can lead to skin cancer. Fortunately, you can protect against many of the damaging effects of these rays with sunscreen. For example in Japan, a cosmetic brand named ‘Biore’ produces a lot of types of sunscreen by categorise them with different SPF+ values. 

These are only some of the products of biore sunscreen. As you can see the left top of the products are stated SPF 50+ which means our skin will prevent burning on the skin for about 500 minutes, or about 8 hours.

WHAT IS THE MEANING OF SPF+, PA+++, UVA AND UVB? 

1. SPF+ basically means a measurement of how much protection the sunscreen offers from the UVB rays that cause sunburn. Meaning to say, the higher the SPF (sun protection factor)  values, the longer time for the sunscreen to maintain on the skin in order to absorb the ultraviolet (UV) radiation from penetrating through the skin. For example, SPF 15+ will prevent burning on the skin for about 150 minutes, or 2.5 hours.

2. PA which refers to the amount of protection the sunscreen offers from the UVA rays that may cause long-term skin damage. PA rankings are listed as PA+, PA++ or PA+++. The more +'s, the more protection from UVA rays.

3.UVA basically means sun's ultraviolet A (long-wave). It penetrates the skin more deeply than UVB, has long been known to play a major part in skin aging and wrinkling (photoaging), but it did not cause significant damage in areas of outermost skin layer where most skin cancers occur.

 

4.UVB is the chief cause of skin reddening and sunburn, tends to damage the skin's more superficial epidermal layers. It plays a key role in the development of skin cancer and a contributory role in tanning and photoaging.

The comparison between UVB AND UVA lights.

DOES SUNSCREEN ONLY PROTECT OUR BODY FROM THE UV LIGHTS ONLY?

In this advanced era globalisation, most of the sunscreen are no longer only absorbs the UV lights into our body but they also came out the function of foundation, BB cream and also moisture (mostly for ladies). This is because their marketing strategy are mostly toward the lady.  

  This sunscreen act as the function of BB cream and also absorb UV light. I’m currently using this! 

  

 This sunscreen provide the function of moisture to our skin and also absorb UV lights. 

WHAT IS ACTUALLY CONTAINS INSIDE THE SUNSCREEN?

SUNSCREEN are so popular used in this generation, but how many people are alerted by knowing the active ingredients or so called organic chemical compounds inside? Are they harmful to our body? Most sunscreens work by containing either an organic chemical compound that absorbs ultraviolet light (such as oxybenzone) or an opaque material that reflects light (such as titanium dioxide, zinc oxide), or a combination of both. 

But today, we will be talking about the organic chemicals in the sunscreen which is OXYBENZONE.

STRUCTURE OF OXYBENZONE

The IUPAC name for oxybenzone is 2-Hydroxy-4-methoxyphenyl)-phenylmethanone.

 Molecular formula is C14H12O3. 

 Molar mass is 228.24 g mol^{-1 .}

HOW DOES THE OXYBENZONE WORKS IN SUNSCREEN?

When the sun penetrate the skin, the bonds in oxybenzone will absorb UV radiation/light, the components of the sunscreen slowly break down and release heat.

WHAT IS OXYBENZONE?

 Oxybenzone belongs to the class of aromatic ketones known as benzophenones. It provides broad-spectrum ultraviolet coverage which is also including UVB and UVA rays. As a photoprotective agent, it has an absorption profile spanning from 270 to 350 nm with absorption peaks at 288 and 350 nm. It is one of the most widely used organic UVA filters in sunscreens today. For the electronic structure, as in related compounds, the hydroxyl group is hydrogen bonded to the ketone. This interaction contributes to oxybenzone's light-absorption properties. The short lifetime has been attributed to an extremely fast and reversible excited-state intramolecular hydrogen transfer between the oxygen of the carbon to oxygen and the OH. This pathway provides a better energy-wasting pathway that is responsible for the absorption functions. 

HOW DOES THE OXYBENZONE MANUFACTURED?

Oxybenzone is manufactured in several different countries including: Israel, The United Kingdom, France, Germany, Taiwan, Japan, and China. One method of manufacturing oxybenzone is to condense benzoic acid with resorcinol monomethyl ether by heating the solution in the presence of ZnCl₂ and polyphosphoric acid. The second method of production utilizes a Friedel-Crafts reaction of benzoyl chloride with 3-hydroxyanisole. The product of this reaction is subsequently recrystallized from a solution of water and methanol and then dried.

SUNSCREEN ONLY CONTAINS OXYBENZONE? 

Of course, sunscreen is not only made by 100% oxybenzone only, this is because with exposure to sunlight, oxybenzone has been found to form free radicals through photogeneration, and therefore may be associated with cell damage. This only occurred when it was combined with other ingredients commonly found in sunscreen, like titanium oxide and octyl methoxycinnamate. On its own, oxybenzone was found to be a preferred UVA filter. 

WHAT ARE THE PRODUCTS ARE MADE UP FROM OXYBENZONE OTHER THAN SUNSCREEN?

It is also found in nail polish, fragrances, hairspray, and cosmetics as a photostabilizer.

DOES THE OXYBENZONE HARMFUL? 

I believe this is the hot topic among all the above. Sunscreen is typically applied topically, but many studies that claim oxybenzone is HAZARDOUS. 

Studies have shown that the oxybenzone is absorbed through the skin and excreted in urine. Up to 1–2% of the applied amount is estimated to be absorbed into the body. However, sunscreen may be putting you on a collision course with cancer. This can be explained by, absorbing chemicals (oxybenzone) through the skin can be more dangerous than ingesting them. This is because they are not decomposed by the potent acid (hydrochloric acid) of the stomach before reaching the blood stream. Stomach acid works to neutralize many chemical toxins, at least partially, and then the remaining toxins are passed through the normal filtration of the digestive system. 

In comparison, chemicals absorbed through the skin do not get diluted, filtered, or neutralized at all. They directly enter into the blood stream, by passing digestive safeguards. This is the predominant reason why people with large amounts of sun exposure statistically have higher rates of skin cancer, for it is their escalated use of sunscreens that is causing the cancers not the sun. 

As we know sun provide Vitamin D which is one of the most effective anti-cancer vitamins, and most cancers occur in people who do not get enough sunlight exposure at days, or vitamin D. But of course! not to expose too long under the sun as you may get skin cancer. 

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