Tuesday 25 March 2014

Introduction


First of all, what is mean by organic chemistry? Organic chemistry is the study of compounds containing carbon that is chemically bonded to hydrogen. All living things are made up of compounds containing mostly carbon but of course, there are many carbon compounds that are human-made or synthetic. For example, plastics. Plastics are human-made but they are organic too because they are carbon-based.   Now, let’s take a look about the reasons why organic chemistry is so important in our daily life. Organic chemistry is important because it is the study of life and all of the chemical reactions related to life. It also helps in finding a process or a product that works in the midst of numerous ideas. Furthermore, it helps in finding out possible solutions to different problems on the earth's surface.Several careers apply an understanding of organic chemistry, such as doctors, dentists, pharmacologists, chemical engineers, and chemists. Organic chemistry plays an important role in the development of common household chemicals such as foods, plastics, soap and detergent and fuels. There are some examples we are going to emphasis and show in our blog! Enjoy!



Processed Foods


Have you ever wondered why peanut butter doesn’t separate? Why baking mixes rise in the oven? Why ice cream is smooth and creamy? Most likely, you take food appearances and quality for granted. 
 
But desirable qualities in processed foods can often be attributed to food additives.



Why Additives Are Used…


Food additives are no secret. The ingredient list on food labels can help you identify specific additives in any food. Additives are used for a variety of reasons:


Ø To Maintain or Improve Nutritional Quality

Ø To Preserve Quality and/or Freshness

Ø To Assist in Processing or Preparation

Ø To Make Food More Appealing




A few examples of processed foods include:

Processed Foods
Examples
Processed fruits

  •           Canned fruit, Fruit jam, Fruit sauces

Additives used: sodium sulfite

Convenience foods

  •         Pizza, Breakfast cereal
Additives used: Ascorbic Acid  (vitamin C, sodium ascorbate)

Processed meat

  •           Canned meat, Sausage, Bacon



Additives used: Sodium Nitrate (potassium nitrate or
nitrite, sodium nitrite)

Processed dairy foods

  •        Cheese, Milk other than raw (homogenized, pasteurized, skim, low-fat, etc.), Yogurt


Additives used: Xanthan gum, emulsifier

Processed fats and oils

  •    Margarine, Salad dressing, Mayonnaise, Peanut butter

Additives used: Mono & Diglycerides (glyceryl monostearate disterate), emulsifier

Confections

  •               Corn syrup, Pudding, Ice cream, Whipped cream


Additives used: Stabilizers, Gelatin, High Fructose Corn Syrup (HFCS)





Processed Meat


When viewing meat products of various size, shape and colour in butcher shops or meat sections of supermarkets, there appears to be is a great variety of such products with different taste characteristics. In some countries there may be several hundred different meat products, each with its individual product name and taste characteristics.

At a closer look, however, it turns out that many of the different products with different product names have great similarities. This issue can be even better understood and becomes more transparent when the processing technologies are analyzed. Based on the processing technologies used and taking into account the treatment of raw materials and the individual processing steps, it is possible to categorize processed meat products in several broad groups. 
  • Fresh processed meat products: Hamburgers, Fried sausages, Chicken nuggets & Kebab.
  • Cured meat pieces: Raw ham, Cooked ham, Bacon, Lunch Meat.
  • Raw-cooked products: Meat Loaf, Frankfurter.



Fresh processed meat products


These products are meat mixes composed of comminuted muscle meat with varying quantities of animal fat. Products are salted only, curing is not practiced. Non-meat ingredients are added in smaller quantities for improvement of flavor and binding, in low-cost versions larger quantities are added for volume extension. All meat and non-meat ingredients are added fresh (raw). Heat treatment (frying, cooking) is applied immediately prior to consumption to make the products palatable. 

If the fresh meat mixes are filled in casings, they are defined as sausages (e.g. frying sausages). If other portioning is customary, the products are known as patties, kebab. Convenience products, such as chicken nuggets have a similar processing technology and can also be included in this group. In contrast to the rest of the group, chicken nuggets etc. are already fried in oil at the manufacturing stage during the last step of production.




Cured Meat


Curing is any of various food preservation and flavoring processes, especially of meat or fish, by the addition of a combination of salt, nitrates, nitrite or sugar. Many curing processes also involve smoking, the process of flavoring, or cooking. The use of food dehydration was the earliest form of food curing.  

Salt-cured meat or salted meat, for example bacon and cooked ham, is meat which preserved or cured with salt. Salting, either with dry salt or brine, was the only widely available method of preserving meat until the 19th century. Salt inhibits the growth of microorganisms by drawing water out of microbial cells through osmosis. Concentrations of salt up to 20% are required to kill most species of unwanted bacteria. Smoking, often used in the process of curing meat, adds chemicals to the surface of meat that reduce the concentration of salt required.


Raw-cooked meat products


The product components muscle meat, fat and non-meat ingredients which are processed raw, i.e. uncooked by comminuting and mixing. The resulting viscous mix or batter is portioned in sausages or otherwise and thereafter submitted to heat treatment, i.e. “cooked”. The heat treatment induces protein coagulation which results in a typical firm-elastic texture for raw-cooked products. In addition to the typical texture the desired palatability and a certain degree of bacterial stability is achieved.



Food additive in processed meats .....

One of the main groups of food additives is preservatives. This preservation involves treating the meat by salting, curing, smoking or using chemical preservatives. Although they don’t usually contain sugar, processed meats, which are heavy on salt and preservatives, seem to be linked to several side effects. Preservative such as sodium nitrite or potassium nitrite play a key role in the safety of processed meats. 

Nitrites, or in slow cured meats sodium or potassium nitrates which are gradually converted to   nitrites, are the key ingredients in meat cures. They provide excellent protection against botulism in processed meats. At the same time their use results in the characteristic colour and flavour of cured meats. Other preservatives inhibit the growth of microorganisms. The sulphites, sources of sulphur dioxide, also inhibit the growth of microorganisms while retaining the bloom (fresh colour and appearance) of red meat.




Excessive intake of food additives in processed meats will cause…


Preservative use is regulated for a number of very good reasons. Some preservatives can have adverse affects on health. The levels of nitrates and nitrites in meat are restricted because they can be converted in the stomach or during high temperature frying to chemicals understood to cause cancer. Sulphur dioxide exposure causes breathing difficulties in some people. Other preservatives can have adverse affects if consumption limits are exceeded. Preservatives can also be regulated to prevent use which is incompatible with other manufacturing processes.


Should we stop eating processed meat all together?
  • Try to cut down on processed meat by having ‘meat-free’ days and trying to opt for organic meat options if budget allows.
  • Check the back of meat packets for extra ingredients that will tell you if it’s been processed to make it last longer.
  • In general, fresh poultry is considered a better option so try replacing heavily processed foods such as ham or sausage with chicken.





Peanut Butter



believed that there aren’t many things peoples enjoy more than a good Peanut Butter & Jam and not all peanut butter is processed in a destructive way, but, unfortunately, most peanut butter is heavily processed. Industrial food producers add stabilizers (food additives) such as mono- and diglycerides to ground peanuts to prevent the natural separation that occurs when a jar of peanut butter sits on a shelf. 

For our information, stabilizers are chemicals that are used to enable oil and water in the food to mix together properly in order to form an emulsion of oil and water. Emulsions are either oil droplets suspended in water or water droplets suspended in oil. It is also added to improve the texture of foods. Therefore, stabilizers function as
  • Mixes two liquids that usually do not mix together.
  • Prevents the sedimentation process of liquids.
  • Provides a smooth and uniform texture of food.
Thus, the reason why peanut butter don’t separate is because the adding of mono-and diglycerides into it.


So what are mono-and diglycerides?


Mono- and diglycerides are emulsifying agents – they are both hydrophilic (attracting water) and hydrophobic (repelling water), so they are soluble in both water and fat, which makes them unique – but not necessarily natural.  They are used to keep oils from separating out of products and used to increase shelf life – the same reasons that trans fats are used in most products. 

Just think of traditional peanut butter - it is smooth and creamy right out of the jar because the trans fat in it prevents the oil from separating out. In fact, you will find mono- and diglycerides in many varieties of peanut butter in addition to bakery products - and you will even find them in most margarine. 

Peanut butter on its own is a food that has an abundance of healthy unsaturated fatty acids (including oleic acid and monounsaturated fat), which are believed to be good for the heart. However, adding trans-fats for consumer appeal and increased shelf life cancels out these health benefits, making processed peanut butter a food that you should avoid.



THE GOOD, THE BAD AND THE UGLY


Peanut butter is one of those highly debatable foods. Some
say it's healthy for you and others beg to differ. It's time to unveil the truth!


First, the good

Of course, peanut butter does have some good qualities that are important to recognize. For those able to control themselves and eat only one serving, peanut butter can actually help aid in weight loss. Chock full of fiber and protein, it helps to keep fuller longer so you eat less overall. Benefits of peanut butter may include: 
  • It's anti-aging. Peanut butter contains antioxidant which can help to reduce the appearance of wrinkles.
  • It's rich in nutrients. Peanut butter is full of vitamin E, calcium, iron, potassium and folic acid — all of which provide for better circulation and cardiovascular health.
  • It can help fight cancer. Loaded with antioxidants, peanut butter can help reduce your risk for cancer and heart disease.

Now, the bad…

Even in moderation, peanut butter does have a few disadvantages that are important to note. Typically, extra sugar is added to many common brands causing the calorie count to be even higher. To keep peanut butter from separating, cheap oils — such as palm oil — are added. Palm oil adds significantly more saturated fat to the already high-in-fat food.  Not to mention it, peanut butter also contains saturated and trans fats. 

These fats are considered the bad fats because they have a negative effect on heart health. Saturated fats increase levels of bad cholesterol without affecting good cholesterol. Trans fats are worse because they increase bad cholesterol while lowering levels of good cholesterol. Apart from it, saturated fats are mainly found in animal-based food products such as high-fat meats, whole milk and full-fat dairy products. 

Monday 24 March 2014

Soap and Detergents



What is soap and detergent?




We use soap and detergent every day. Detergent is a cleaning agent that helps to remove dirt and grease from porous surface such as fabrics, clothes, non-treated wood) and non-porous surface (such as metals plastics and treated wood). On the other hands, soap helps to remove dirt from our body and keeps us clean.


Soaps




Soaps are water-soluble sodium or potassium salts of fatty acids.Soap is made from a fatty acid that is reacted with an alkali. The acid end of the fatty acid reacts with the alkali to form a salt that is water-soluble. The other end is the fatty end, which repels water, and is attracted to fats and oils. The process of making soap is called saponification. One kind of soap is sodium stearate. Beef fat reacting to alkaline wood ashes created the earliest soap, and it was the cleaning product of choice for millenia.
  
Detergents



Detergentsare usually sodium slats of sulphonic acid and are refers to a water-soluble cleansing agent that combines with impurities and dirt to make them more soluble. It differs from soap in not forming a scum with the salts in hard water.Detergents have molecules with one side that prefers water (hydrophilic), and another side that prefers oils and fats (hydrophobic). The hydrophilic side attaches to water molecules, and the hydrophobic side attaches to oil molecules. This action allows the oil droplets to break up into smaller droplets, surrounded by water. These smaller droplets are no longer stuck to the material to be cleaned, and are washed away.

 





What do soaps and detergents contain?


Water, the liquid commonly used for cleaning, has a property called surface tension. In the body of the water, each molecule is surrounded and attracted by other water molecules. However, at the surface, those molecules are surrounded by other water molecules only on the water side. A tension is created as the water molecules at the surface are pulled into the body of the water. This tension causes water to beat up on surfaces (fabric and others), which slows wetting of the surface and inhibits the cleaning process. You can see surface tension at work by placing a drop of water onto a counter top. The drop will hold its shape and will not spread.Surface tension must be reduced so water can spread and wet surfaces.

Soaps and detergents contain surfactants (surface active agents). Surfactants are saidto make water "wetter." This ability increases the contact between the soil and the detergent solution and allows it to penetrate the minute irregularities of the dirt more effectively. They contain a combination of fats (triglycerides) and alkali that create molecules with two unique chemical ends. The “hydrophilic” end is attracted to water and the “hydrophobic” end attracted to the grease and oil. The hydrophobic ends bond with the dirt and the hydrophilic ends lie up around them, encapsulating dirt and grease with a layers of molecules that allows to float through water.

Moreover, surfactants perform other important functions in cleaning, such as loosening, emulsifying sink dishes(dispersing in water) and holding soil in suspension until it can be rinsed away. Surfactants can also provide alkalinity, which is useful in removing acidic soils. In addition, it is also a substance that was resistant to hard water was needed to make cleaning more effective. Soap is an anionic surfactant. Other anionic as well as nonionic surfactants are the main ingredients in today's detergents. There are 4 typessurfactants are available, which are:
 
1.  Anionic - the active part is negatively charged and generally is a good foamer and has good wetting properties.

2. Cationic - the active part is positively charged and generally is biocidal. 

3. Amphoteric - which is cationic in acid medium and anionic in alkaline medium. Can sometimes be biocide.

4. Non-ionic surfactant, these have no overall charge but are very good emulsifying agents.






Some laundry detergents contain "optical brighteners". These are fluorescent dyes that glow blue-white in ultraviolet light. The blue-white color makes yellowed fabrics appear white. Moreover, laundry detergent may also contain phosphate and polyethylene glycol, a polymer that prevents dirt from re-depositing on the clothes. Another polymer used for this purpose is carboxyl methyl cellulose. This is derived from natural cellulose, but is very soluble in water.

Yet another ingredient in laundry detergents is Diethyl Ester Dimethyl Ammonium Chloride (DEEDMAC). It is a fabric softener. It is a cationic surfactant that is rapidly biodegradable. It works by reducing the friction between fibers, and between fibers and the skin. Cationic surfactants are those where the hydrophilic part (in this case the ammonium chloride) is positively charged, and is attracted to substrates that are negatively charged, such as proteins and many synthetic fabrics. Hair conditioners use this trick also. You can think of a hair conditioner as fabric softener for your head.




How do soaps and detergents work in cleaning?


Soaps and detergents are used frequently in our daily life, but we use without ever really paying attention to how they work. The cleansing action of both soaps and detergents results from their ability to lower the surface tension of water, to emulsify oil grease and to hold them in suspension in water.

The 3 most important energy needed in cleaning process are;
Chemical energy: which are provided by the soap and detergent.
Thermal energy: which are provided by the warm or hot water.
Mechanical energy: which are provided by the hand or washing machine
To know better let see the explanation below!

Let's assume we have oily, greasy soil on clothing. Water alone will not remove this soil. One important reason is that oil and grease present in soil repel the water molecules. 
 What to do? 

Now let's add soap or detergent, which provide chemical energy in cleaning.In water, a sodium soap dissolves to form soap anions and sodium cations.  The soap anion consists of a long hydrocarbon chain with carboxylate group on one end. The hydrocarbon chain is hydrophobic, which is soluble in grease and oils. The ionic part is the carboxylate group which is hydrophilic (soluble in water). These opposing forces loosen the soil and suspend it in the water.
CH3(CH2)14COO-Na+àCH3(CH2)14COO- + Na+

On the other hand, detergent dissolves to form detergent anions and cations. Similarly, the anion part of detergent also consists of hydrophobic part and hydrophilic part.These opposing forces loosen the soil and suspend it in the water.



Warm or hot water (which is the thermal energy) helps dissolve grease and oil in soil. To speed up the cleaning process, we need mechanical energy which we need to use a washing machine agitation or hand rubbing helps pull the soil free.

Below shows some diagram of how soap and detergent work in cleaning.



 

  



Effectiveness of cleaning action of soaps and 


Detergents are better than soaps in hard water! Soaps are only suitable for the use in soft water. Soft water is water that contains little or no calcium and magnesium ions. Soaps do no form scum with soft water. Although soap is a good cleansing agent, but its effectiveness will reduce when use in hard water. Hard water is water that contains calcium and magnesium ions. These ions react with soap to form an insoluble precipitate known as soap scum. The formation of soap scum reduces the amount of soap available for cleaning, thus causes wastage of soap.
  
Detergents do not form scum with hard water, it form soluble subtances with calcium and magnesium salts. Thus it can perform its cleansing action in hard water and it is more effective then soap in hard water.

Soap in hard water…(RCOONa=Soap)
RCOONa(aq)+ Mg2+(aq) à (RCOO)2Mg (s) (scum)+ 2Na+(aq)
RCOONa(aq) + Ca2+(aq) à (RCOO)2Ca (s) (scum)+ 2Ca+(aq)

Detergent in hard water…(ROSO3Na=Detergent)
ROSO3Na (aq) + Mg2+ (aq) à (ROSO3)2Mg (aq) + 2Na+(aq)
ROSO3Na (aq) +Ca2+ (aq) à(ROSO3)2Ca (aq) + 2Ca+(aq)

The effectiveness of the cleansing action of soap also reduced when used in acidic water. The hydrogen ions in acidic water react with the soap to form long chain fatty acid, which is insoluble in water due to their high relative molecular masses. This reduces the amount of soap available for cleaning. Detergent do not form precipitates in acidic water. Thus, their cleansing action is not affected.

Soap in acidic water…
RCOONa (aq) + H+(aq) à RCOOH (s) + Na+(aq)
Detergent in acidic water…
ROSO3Na (aq) + H+(aq) à ROSO3 H (aq) + Na(aq)


Difference between soap and detergent



Soap
Detergent
Made from neutral resources
(animal fats and vegetables oils)
Made from synthesis resources
(petroleum fraction)
Form scum in hard water
Do not form scum in hard water
Effective cleaners in soft water
Effective cleaners in both soft and hard water
Form precipitate in acidic water
Do not form precipitate in acidic water
Biodegradable
(Do not cause pollution)
Non-biodegradable
(produce thick foam that kills aquatic live)



What to use in the process of making soap?
1. Fats and Oils
2. Alkali






Fats and Oils…
The fats and oils are come from animal or plant sources. Each fat or oil is made up of a distinctive mixture of several different triglycerides. In a triglyceride molecule, three fatty acid molecules are attached to one molecule of glycerine. There are many types of triglycerides; each type consists of its own particular combination of fatty acids.
Fatty acids are the components of fats and oils that are used in making soap. They are weak acids composed of two parts:
A carboxylic acid group consisting of one hydrogen (H) atom, two oxygen (O) atoms, and one carbon (C) atom, plus a hydrocarbon chain attached to the carboxylic acid group. Generally, it is made up of a long straight chain of carbon (C) atoms each carrying two hydrogen (H) atoms.



Alkali…
An alkali is a soluble salt of an alkali metal like sodium or potassium. Originally, the alkalis were obtained from the ashes of plants, but they are now made commercially. Today, the term alkali describes a substance that chemically is a base (the opposite of an acid) and that reacts with and neutralizes an acid.The common alkalis used in soapmaking are sodium hydroxide (NaOH), also called caustic soda; and potassium hydroxide (KOH), also called caustic potash.






The process of making soap


Soap was made by the batch kettle boiling method until shortly after World War II, when continuous processes were developed. Continuous processes are preferred today because of their flexibility, speed and economics
Natural soaps are sodium or potassium salts of fatty acids, originally made by boiling lard or other animal fat together with lye or potash (potassium hydroxide). Hydrolysis of the fats and oils occurs, yielding glycerol and crude soap.In the industrial manufacture of soap, tallow (fat from animals such as cattle and sheep) or vegetable fat is heated with sodium hydroxide.
Both continuous and batch processes produce soap in liquid form, called neat soap, and a valuable by-product, glycerine(1). The glycerine is recovered by chemical treatment, followed by evaporation and refining.Once the saponification reaction is complete, sodium chloride is added to precipitate the soap. The water layer is drawn off the top of the mixture and the glycerol is recovered using vacuum distillation. Vacuum distillation is used to convert the neat soap into dry soap pellets (2). 
In the final processing step, the dry soap pellets pass through a bar soap finishing line. The first unit in the line is a mixer, called an amalgamator, in which the soap pellets are blended together with fragrance, colorants and all other ingredients (3). The mixture is then homogenized and refined through rolling mills and refining plodders to achieve thorough blending and a uniform texture (4). Finally, the mixture is continuously extruded from the plodder, cut into bar-size units and stamped into its final shape in a soap press (5).
Some of today's bar soaps are called "combo bars," because they get their cleansing action from a combination of soap and synthetic surfactants. Others, called "syndet bars," feature surfactants as the main cleansing ingredients. The processing methods for manufacturing the synthetic base materials for these bars are very different from those used in traditional soapmaking. However, with some minor modifications, the finishing line equipment is the same.
Saponification reaction






The process of making detergent.

During the past century, the shortage of animal and vegetable fats during World War 1 and World War 2 lead to the development of detergents. During the preparation of detergents, a long chain of hydrocarbon obtained from petroleum fractions is converted into organic acid through a series of steps. The organic acid is then neutralized with sodium hydroxide solution to produce a neutral salt, which is detergent. Two commons detergents are sodium alkyl sulphate and sodium alkyl benzene sulphonate. These two detergents are prepared using different method. Let us see the preparation of sodium alkyl sulphate first.

First step, formation of organic acid (sulphonation). Concentrated sulphuric acid is added to the long chain alcohol. Then alkyl sulphonic acid and water is produced. The second step is neutralization. Sodium hydroxide solution is added to alkyl sulphonic acid to produce water and sodium alkyl sulphate.
*R = long chain hydrocabon



As for the preparation of sodium alkyl benzene sulphonate, the first step is sulphonation. Concentrated sulphuric acid is added to alkyl benzene to produce alkyl benzene sulphonic acid and water. The second step is neutralization. Alkyl benzene sulphonic acid is mixed with sodium hydroxide solution to produce sodium alkyl benzene sulphonate and water.