Chemicals in Foods
All those chemical which are added to food to improve its keeping
qualities, appearance, taste, and odour are called the food additives.
1. Food Colours
2. Flavours and Sweeteners
3. Preservative
4. Nutritional Supplements.
ARTEFICAL SWEETNING AGENTS:-
Sucrose and Fructose used as normal sugar add to our calorie intake and
promote tooth decay to avoid this we use artificial sweeteners
a. Saccharin:-
It is most popular artificialsweetener. It is insoluble in water. It is
550 times sweeter than sugar. It is not biodegradable and does not have
any calorific value of food.
b. Aspartame:-
It is methyl ester of dipeptide derived from phenylalanine and aspartic
acid. It is 100 times sweeter than sugar. It decomposes at baking or
cooking temperature thus it can be only used in cold foods and soft
drinks.
c. Alitame:-
It is more stable than as partake. It is nearly 2000 times sweet as
sugar. It is difficult to control the sweetness of food which they are
added.
PRESERVATIVES:-
Chemical substances which are used to protect food against Bacteria, Yeasts and Moulds are called preservatives.
Examples:-
1. Sodium Benzoate:-
The most commonly used preservative sodium benzoate. It is used in soft drinks and acidic foods.
Sodium and Calcium propionates are used in breads and cakes as mould inhibitor.
2. Sodium Metabisalphite:-
Sodium or potassium metabisulphite is used for preserving James,
Squashes, Pickles etc. other important preservatives are Sorbic acid,
Epoxides, Sirca, Nitrogen, Hydroxy benzoate esters etc.
ANTIOXIDENTS:-
Chemical which are used to prevent the oxidation of fats in processed foods such as potato chips are called.
Antioxidants:-
Ascorbic acid (Vitamin C) and tocopherols (Vitamin E) are used as Antioxidants.
CLEANSING AGENTS:-
Soaps and Detergents:-
Chemical substances which concentrates at the surface of the solution or
interfaces, farms surface Films, reduced surface tension of solution
helps in removing dirt and dust by emulsifying grease are called
surfactants. They are soaps and detergents.
Soaps:-
They are sodium or potassium salts of higher fatty acids such as lquric acid [C11H23COOH], steric acid [C17H35COOH] etc.
Soaps are formed by heating fat or oil with aqueous sodium hydroxide solution. This reaction is called saponification reaction.
Only sodium and potassium soaps are soluble in water and are used for thecleansing purpose.
1. Toilet Soaps:-
Toilet Soaps are prepared by using better grades of fats and oils and core is taken to remove excess alkali.
2. Landry Soaps:-
Used for washing clothes, contains fillers like sodium rosin ate, sodium
silicate, borax and sodium carbonate. Other kinds of soaps are –
shaving soaps, floating soaps, transparent soaps etc.
ADVANTAGE AND DISADVANTAGE OF SOAPS:-
1. Soap is good cleanising agent is 100% biodegradable, it does not create any pollution but it have disadvantage also:
a. Soaps cannot be get used in hard water since calcium and magnesium
ions present in hard water produces curdy white PPt with calcium and
magnesium salt of fatty acids.
b. Soaps cannot be used in acidic solution. Since acids precipitate the insoluble free fatty acids.
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