Lipids
Lipids are naturally occurring organic compounds of animals and plants origin and are soluble in
organic solvents. Lipids compounds are composed of carbon, hydrogen and oxygen but the ratio
between hydrogen and oxygen is not 2:1. The main characteristics are as,
i.
Insoluble in water and soluble in non – polar solvents.
ii.
Their primary building blocks are fatty acids, glycerol and sterols.
iii.
They are used by the living organism for the energy.
Fats and oils are the most important lipids and are obtained from animals, plants and marine
sources. Animal fats like butter and ghee, vegetable oil from seeds of plants and marine
oils from sea animals are in use.
The differences between fat and oil is as,
Fats
i. Solid or semi-solid at room
temperature (25°C)
ii. High proportion of long chain
saturated acid components.
iii. High melting and boiling points
iv.Extracted from animals
Oils
i. Liquids at room temperature (25°C)
ii. High proportion of long chain
unsaturated acid components
iii. Low melting and boiling points
iv. Extracted from plants
These are classified as,
i.
Simple lipids are esters of fatty acids with glycerol e.g. common fats and oils.
ii.
Compound lipids contain radicals in addition e.g. glycerol phospholipids.
iii.
Derived or associated lipids are the hydrolytic products of compound lipids e.g.
sterols.
Physical properties of fats and oils:
The physical properties are as,
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i.
State: Liquid or non-crystalline solids
ii.
Color, smell, taste: Colorless, odorless and tasteless in pure form
iii.
Solubility: Insoluble in water and soluble in non-polar solvents
iv.
Emulsion: Form emulsion with water on agitation
v.
Conductivity: Poor conductors of heat and electricity
Steroids and their types
A steroid is a biologically active organic compound with four rings arranged in a
specific molecular configuration. Steroids have two principal biological functions: as important
components of cell membranes that alter membrane fluidity; and as signaling molecules. Hundreds
of steroids are found in plants, animals and fungi. Steroids are the naturally occurring lipids which
consists
of
three
six
membered
rings
and
one
five
membered
ring
called
perhydrocyclopentanophenanthrene component. These three rings are fused together and have 17
– carbon atoms. The different types of steroids are cholesterol (animal sterol), ergosterol (on
irradiation to U.V is changed to ergocalciferol or vitamin D2), male & female sex hormones and
hormones of adrenal cortex.
CH3 R
CH3
A
C
D
B
Structure of Steroid
Cholesterol
Cholesterol is a form of lipids, just as fats are. It is a sterol (or modified steroid), a type of
lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component
of animal cell membranes. When chemically isolated, it is a yellowish crystalline solid.
Cholesterol
also
serves
as
a precursor for
the biosynthesis of steroid
hormones, bile
acid and vitamin D. Cholesterol is the principal sterol synthesized by all animals including beef,
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chicken, fish, poultry, organic meat and high fat dairy foods. In vertebrates, hepatic cells typically
produce the greatest amounts. It is mostly absent among prokaryotes (bacteria and archaea).
Cholesterol is a 27 carbon compound with a unique structure with a hydrocarbon tail, a central
sterol nucleus made of four hydrocarbon rings, and a hydroxyl group. The center sterol nucleus or
ring is a feature of all steroid hormones.
Cholesterolemia
Cholesterolemia is the presence of cholesterol in your blood. Your body needs cholesterol
to form cell membranes and hormones as well as help the body process certain vitamins and fats.
Your body relies on the right balance of cholesterol to perform its daily functions.
Hypercholesterolemia
An
elevated
levels
of
cholesterol
in
the
blood
lead
hypercholesterolemia.
Hypercholesterolemia is a lipid disorder in which your low-density lipoprotein (LDL), or bad
cholesterol, is too high. This makes fat collect in your arteries (atherosclerosis), which puts you at
a higher risk of heart attack and stroke.
Hypocholesterolemia
Abnormally
low
levels
of
cholesterol
is
termed as
hypocholesterolemia.
Hypocholesterolemia is defined as total cholesterol (TC) and low density cholesterol (LDC) levels
below the 5(th) percentile of the general population adjusted for age, gender and race.
Hypocholesterolemia may be attributed to inherited disorders or several secondary causes.
Hypocholesterolemia was defined as a total cholesterol concentration of less than 150 mg/dl. The
health issues linked with hypocholesterolemia are depression, cancer, and cerebral hemorrhage.
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Cholesterol testing
The American Heart Association recommends testing cholesterol every 4–6 years for
people aged 20 years or older. A blood sample after 12-hours of fasting is taken by a healthcare
professional from an arm vein to measure a lipid profile.
Lipid Profile:
a) Total cholesterol
b) HDL cholesterol (called good fats such as olive oil, sunflower oil)
c) LDL cholesterol or VLDL (both called bad fats such as trans-fat)
d) Triglycerides.
Lipid profile normal or desirable levels:
 Total cholesterol………………..200 mg/dL or less

HDL value……………………….40 mg/dL, or higher ("the higher, the better")

LDL value………………………..100 mg/dL or less than

Triglycerides level………………150 mg/dL or less than
Importance of lipids
The importance of lipids is as,
i.
Good source of energy
ii.
Insulating effect on the nervous tissue
iii.
Integral part of the cell protoplasm and cell membranes
iv.
Precursors of very important physiological compounds
v.
Excellent source of energy (9.1 calories per gram)
vi.
Fats prevent heat loss and water loss
Trans-fat is a type of dietary fat. Of all the fats, trans fat is the worst for your health. Too much
trans-fat in your diet increases your risk for heart disease and other health problems. Trans-fats
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are made when liquid oils are turned into solid fats, like shortening or margarine. Trans-fats
are present in fried foods, commercial baked goods, processed food and margarine.
Explanation of Lipid profile or lipid panel:

Total cholesterol: This is the total amount of cholesterol that’s circulating in your blood.
Here’s the formula for calculating it: HDL + LDL + 20% triglycerides = total cholesterol.

HDL level: HDL is high-density lipoprotein. This is the “good” cholesterol that moves
extra cholesterol from your bloodstream to your liver. Your liver then gets rid of it from
your body. When you see HDL, think of “h” for helpful. HDLs help your arteries clear out
the cholesterol your body doesn’t need. It’s the one number in your lipid panel that you
want to be high. Omega-3/ Omega-6 are good fats present in fish and good for health of
human heart.

LDL level: LDL is low-density lipoprotein. This is the “bad” cholesterol that contributes
to plaque buildup in your arteries. You need some LDLs because they carry cholesterol to
your body’s cells. But having too many can cause problems.
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
VLDL level: VLDL is very low-density lipoprotein. It’s another “bad” form that
contributes to plaque buildup. VLDLs carry a type of fat (triglycerides) in your blood. If
you have too many VLDLs, the extra fat can build up in your arteries.

Triglycerides: This is a type of fat. You need some triglycerides. But high levels
(hypertriglyceridemia) can put you at risk for atherosclerosis and other diseases.

Non-HDL cholesterol: This is all the cholesterol in your blood that isn’t HDL. The
formula for calculating this number is simple: Total cholesterol – HDL = Non-HDL
cholesterol
Minerals
Minerals are elements or components which are present in food and are required by the body for
developing and functioning properly. Minerals are inorganic substances and helps to maintain
various bodily functions.
Macrominerals

Macrominerals are those minerals which are required in relatively large doses. Therefore,
they are also called major minerals.

Macrominerals include sodium, calcium, magnesium, potassium and phosphorus.
These minerals are vital for the proper functioning and metabolism of the body. Our body
cannot produce these minerals; hence, they need to be obtained from a food source.
Calcium > phosphorus > potassium > sodium > magnesium
Teeth and boned are made up of calcium phosphate Ca3(PO4)2
Microminerals
Also called trace minerals, these are minerals which are required in small amounts.
Therefore, they are also called minor minerals. Trace minerals include iron, copper,
iodine, zinc, manganese, fluoride, cobalt, chloride, sulfur and selenium.
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Mineral
Function
Source
Calcium: Calcium is the
most abundant mineral in the
human body, making up 1.5
to 2% of the total body
weight.
 Helps blood clotting.
Almonds, Carrots, Milk,
Broccoli, Canned Fish,
Papaya, Garlic, and Cashew
 Helps muscle contraction
and nerve function.
 Essential for building strong
and healthy bones.
Macro
Chloride
Micro
Cupper
 Maintains proper blood
volume, blood pressure, and
pH of our body fluids.
 Formation of red blood cells.
 Helps with the functioning
Micro
Iodine
Micro
Iron
Micro
Magnesium
Macro
of the nervous system.
 Promotes the normal
functioning of the thyroid
gland.
 Helps in the proper
functioning of brain
functions.
 Promotes normal growth and
development of cells.
 Helps in transporting oxygen
to all parts of the body
(Hemoglobin).
 Produces and stores the
energy for further
metabolisms.
 Low levels of iron cause
anemia
 Provides structure for
healthy bones.
 Produces energy from the
food molecules.
Table Salt, Soy Sauce, liver
Unprocessed Meat, Milk and
Peanuts
Crab, Lobster, Mussels,
Oysters, Nuts, Wholegrains
and Yeast extract
Seafood, Seaweed and
Iodised salt
Meat, Eggs, Beans, Baked
Potato, Dried Fruits, Green
Leafy Vegetables, Whole and
Enriched Grains
Honey, Almonds, Seafood,
Tuna, Chocolates, Pineapple,
Pecans, Artichokes, and
Green Leafy Vegetables
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 Maintains proper
functioning of muscle and
nervous system.
Manganese
 Helps maintain water
Micro
balance.
 Controls nerve impulse
transmissions.
Sodium
Macro
Sulfur
Micro
Phosphorous
Macro
Potassium
Macro
 Maintains cellular osmotic
pressure.
 Helps in maintaining blood
volume and blood pressure
and fluid balance in the
body.
 Involved in protein
synthesis.
 Protects your cells from
damage.
 Helps in promoting the
loosening and shedding of
Skin.
 Helps the body store and use
energy.
 Works with calcium in the
formation of strong, healthy
bones and teeth.
 Controls nerve impulses and
muscle contractions.
 Helps in maintaining fluid
balance in the body.
 Maintains proper
functioning of muscle and
nervous system.
 Aids in wound healing.
Zinc
Micro
 Supports the immune
system.
Cereals, Nuts, Oils,
Vegetables and Wholegrains
Table Salt, Cheese, Milk,
Soy Sauce, and Unprocessed
Meat
Cheese, Eggs, Nuts, Turnips,
Onions, Fish, Wheat Germ,
Cucumbers, Corn,
Cauliflower, and Broccoli
Mushrooms, Meat, Cashews,
Oats, Fish, Beans, Squash,
Pecans, Carrots, and Almonds
Spinach, Apples, Oranges,
Tomatoes, Papaya, Bananas,
Lemons, Celery, Mushrooms,
Pecans, Raisins, Pineapple,
Rice, Cucumbers,
Strawberries, Figs, Brussels
Sprouts, and Legumes
Beef, Pork, Dark Meat,
Chicken, Cashews, Almonds,
Peanuts, Beans, Split Peas,
and Lentil
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vegies
 Helps in the formation of
Cobalt Micro
strong bones.
 Controls the functioning of
the sense organs in the
nervous system.
 Important and essential
process of cell division and
reproduction.
Vit B 12 (Cobalamine)
Food deterioration
Food deterioration is defined as a process that renders a product (food) unacceptable or
undesirable for consumption and is the result of the biochemical activity of microbial populations
that predominate in the product. When food items kept for a long time gets spoil as germs start
growing on it. Spoilage is a process in which food items deteriorate to the point in which it is not edible
to human.
Types of deterioration in objects

Physical agents: The four major factors which affect food nutrients physically are light,
oxygen concentration, temperature and water activity.

Chemical agents: occurs as a result of a chemical reaction between objects and their
environment.

Biological deterioration: occurs as a result of living organisms such as insects, bacteria,
and mold.

Mechanical deterioration: Unsafe transportation and supply of food.
Traditional Methods
1. Freezing: In this method, food is cooled below 0 °C. Food kept in a refrigerator remains fresh for
some days. Germs do not grow easily in cool places. We preserve food items, like milk fruit, vegetables
and cooked food by keeping them in a refrigerator. Deep freezing: Keeping food, vegetables, meat
and fish in the freezer for a long period.
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2. Boiling
By this method, we can preserve food for a short period of time by heating or boiling. Germs in milk
are killed boiling. It is done by boiling milk for sometimes and then cooling it quickly.
3. Salting
We can add salt to preserve pickles and fish. Salt addition cause dehydration (removal of water) which
inhibits the growth of microbes.
4. Sweetening
Excess sugar in food also acts as a preservative. We store food for a long time in the form of jams,
jellies, and murabbas by adding sugar. Sugar remove water contents of food through osmosis.
5. Dehydration
In this method, the food items are dried in sun to stop the growth of bacteria in them. Certain foods,
like raw mangoes, fishes, potato chips and papads are preserved by this method.
6. Canning
In this method, air is removed from food and put in airtight cans so that germs do not grow on them.
Some food items are heated at a very high temperature and after that, sealed in a metallic container
(metallic containers are mostly made up of tin or aluminum). Food items like vegetables, seafood,
corn, dairy products etc are preserved through this method.
7. Pickling:
Pickling is a process in which an anti-microbial liquid oil (mustard oil) is added into food as pickling
agent. Sometime salt and spices are also added. Example vegetables, peppers, lemons and fruits
(mango).
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