FOOD
SOURCES
Foods in general contain two types
of fat namely 'visible fats' and 'invisible' or 'hidden' fats.
Visible fats
Visible fats are fats extracted from
the following sources. a. Oil seeds :
coconut, corn, cornseed, groundnut, mustard,
palm, rice bran, safflower, seasame, soyabean, sunflower and
hydrogenated vegetable oils (vanaspathi).
b.Animal
fats: Butter and Ghee.
c.
Fish oils:Shark
and cod liver oils.
Invisible or hidden fats:
Invisible or hidden fats are those which form an integral
part of foods and are therefore not visible. It includes the fats present in
the cells and cell walls and cell membranes of both plant and animal tissues.
Almost everything we eat as listed
below carries some invisible fats.
a)
Plant food - Cereals, millets,
vegetables, spices, nuts and oil seeds, coconut, avacado.
b)
Animal food - Milk and milk products
(curd, cream, cheese), flesh foods, (mutton, beef, pork, chicken) organ meats
(brain, liver, kidney), fish, shrimp, prawn.
Sources of Saturated Fat:
Saturated fat is resistant to
oxidation even at frying temperatures. Examples are
a)
Plants - coconut oil. Hydrogenated
vegetable oils. Palm kernel oil.
b)
Animals - Butter, ghee, fats from
flesh foods and organ
meats.
Sources of Unsaturated Fat:
Unsaturated fats and oils include mono unsaturated fatty
acids and PUFA in various proportions.
Important sources of unsaturated fats are as follows: Plant
sources:
All common vegetable oils with the exception of coconut oils
are predominantly unsaturated. The invisible fats present in nuts and oilseeds,
cereals, pulses and legumes, roots and tubers, vegetables, spices and fruits.
In most plant foods and vegetable
oils linoleic acid is the predominant PUFA, but mustard and soyabean oils,
legumes/pulses. Fenugreek leaves, and green leafy vegetables are good sources
of alpha linolenic acid.
Animal
sources:
The
muscles (lean meat) of flesh foods, unlike the depot fat surrounding the
tissues is mainly composed of cholesterol
esters and phospholipids, both of which have a high proportion of long
chain n-6 PUFA which are otherwise formed in the body from linolenic acid.
Arachidonic acid is found in animal
and human cells. Fish and fish oils provide long chain n - 3 PUFA.
Hydrogenation:
Hydrogenation (addition of hydrogen
at double bonds) converts liquid oils into semisolid or solid fats. During
hydrogenation, linoleic and alpha linolenic acid present in the oils are
converted to trans fatty acids and saturated fatty acids. Also, the
monounsaturated fatty acids are converted to saturated fatty acids.
Hydrogenated fats were designed to
imitate ghee. It is used to prepare processed foods like biscuits and cakes.
Vanaspathi is produced in India by hydrogenation of vegetables oils.
Cholesterol:
Cholesterol is a constituent of animal foods but is absent
in plants. Vegetable oils do not have cholesterol. In human diets, cholesterol
is obtained from ghee, butter, cheese, milk, curd, egg, flesh foods, organ
meats, fish and prawns. Most animal foods are good sources of both cholesterol
and fatty acids.
Related Topics
Privacy Policy, Terms and Conditions, DMCA Policy and Compliant
Copyright © 2018-2023 BrainKart.com; All Rights Reserved. Developed by Therithal info, Chennai.