Page 20 - ICSE Chemistry 6

as well as our environment. Food, clothing, shelter, medicines, hygiene, fer lisers, drugs and entertainment
are all gi s of chemistry.

FOOD AND CHEMISTRY

Food and Its Preservatives

Increase in popula on has led to increased demand for food. Consequently, preserva on of food is vital
in order to prevent wastage of food and make it available to the consumers. This has been taken care of
with the help of chemistry.
The chemicals used to preserve food and control its wastage are known as food preserva ves. Some food
preserva ves used to preserve various food items are as follows.
•Sodium benzoate is used to preserve food items such as fruit products, beverages and salads.
•Sugar, salt and vinegar are o en used as preserva ves. Sugar and salt help in preven ng the growth
of bacteria in food items.
•Sorbic acid, and its sodium and potassium salts are used for preserva on of food items such as
dairy products, fi sh and seafood, fruit and vegetable products, fat-based products, baked foods
and cookies.
•Some other food preserva ves used are sodium metabisulphite, salicylic acid, benzoic acid and
propionic acid.

Thirst for Knowledge

Development and applica on of new techniques has increased crop yield and provided ways to produce
disease-free crop.
• Fer lisers: They are chemicals which provide nutrients required by
crops for a proper growth. The use of fer lisers also increases the
yield. Urea, sodium nitrate, potassium and ammonium phosphate
are some examples of fer lisers.
• Pes cides: They are used by farmers to kill pests aff ec ng crop
produc on and growth of fruits. Aldrin, malathion and parathion are
some major pes cides used on crops and fruits against pests.

• Insec cides: They are the chemicals used to kill insects that aff ect the growth of crops. Some examples
of insec cides are benzene hexachloride (BHC), dichlorodiphenyltrichloroethane (DDT) and carbaryl.

• Fungicides: They are chemicals that prevent crops from being aff ected by fungi. Sulphur, calcium
polysulphide and ethylene oxide are some examples of fungicides.

Food Processing

Food processing refers to the process of transforming raw materials by physical or chemical method into
marketable food products. These food products are made suitable for consump on, cooking or storage
and are called processed foods. Various addi ves are added to these products in order to increase their
shelf life. In addi on to this, various vitamins and minerals are also added to enhance their nutri onal
value. Cheese, bread, jam, jelly, bu er, snacks, so drink, nned food, meat products, yogurt and ice
cream are some examples of processed foods.

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