Technology of fats and oil (B.Tech Food Technology)

Technology of Fats and Oils
BTech Food Technology
Chirantan Sandip Saigaonkar
FTS/2020/41

• Fats protect internal organs
from shock and injury, insulate
the body, and promote healthy
skin.
• Fats provide 9 calories per
gram.
Introduction

• Oils are fats that are liquid at room temperature
whereas fat is solid at room temperature.
• Oils come from different plants and from fish
• Lipids- A family of chemical compounds,
which include fats and oils
• Cholesterol- a fat-like substance made of
glucose or saturated fat (in our blood)

Classification of lipids
Simple lipids

FUNCTION OF FAT
• Supplies heat (insulation)
• Carries Vitamin A,D,E,K (the fat soluble
vitamins)
• Adds flavor to food
• Satisfies hunger, feel fuller longer
• Protects organs from shock and injury
• Promotes healthy skin

Visible Fat: Can be seen with eyes, like
fats and oils after extraction
Invisible Fat: Fats that are not
immediately noticeable such as in egg
yolk, cheese, cream, nuts , dry fruits etc.

Chemically fats and oils are known as Triglycerides

Fatty Acids
• Fatty Acids are the chemical chains that make up
fats. They have 2 categories:
• The body needs fatty acids to transport other
molecules such as fat-soluble vitamins (ADEK).
• Vitamins A,D,E & K- only dissolve in fatty acids
not in water
• All other types of vitamins dissolve in water
SATURATED UNSATURATED
Saturated Polyunsaturated
Monounsaturated

Fatty Acids and their types
• Saturated
• Monounsaturated
• Polyunsaturated

Saturated Fatty Acids
Fats that usually come from ANIMAL sources and fatty
acid has no double bond in it
Mono-unsaturated Fatty Acids
Fat is usually semi-liquid at room temperature and
sources are canola, olive oil etc and fatty acid has one
double bond

Poly-unsaturated Fatty Acids
Fat is usually liquid at room temperature and sources are corn oil,
soybean oil, fish oil, linseed oil etc. and fatty acid has two or more than
two double bond.

Trans Fat
• Trans fat is an unsaturated fat
molecule chemically changed to be a
solid fat.
• It has longer shelf life and is less
expensive
• Trans fats can cause HEART
DISEASE.

Essential Fatty acids
These fatty acids can not be synthesized
by the body and must be obtained from
the diet. Linoleic acid and linolenic acid
are the two essential fatty acids.
Non- essential fatty acids
Can be synthesized by the body.

Antithrombotic effects of n-3 PUFAs and exercise
Stupin et al, 2019: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC

Long chain fatty acids are made from Palmitate

Physical characteristics of fats and oils
The analysis of the physical properties of oils and fats
allows us to understand the behavior and characteristics
given as below:
Crystallization
Melting point
Viscosity
Refractive index
Density
Solubility
Plasticity
Emulsifying capacity

Crystallization
Fats differ from oils in their degree of solidification at room temperature,
since in these conditions the oils are in a liquid state (not crystallized) while
the fats are in the solid (crystallized) state.
The proportion of crystals in fats have great importance in determining the
physical properties of a product. Fats are considered solid when they have at
least 10% of their crystallized components.
The fat crystals have a size between 0.1 and 0.5 μm and can occasionally
reach up to 100 μm. The crystals are maintained by Van der Walls forces
forming a three-dimensional network that provides rigidity to the product.
Fat can exist in different crystalline form and this phenomenon is called as
polymorphism.
An important feature of fat is its crystalline polymorphism since mono-di and
triglyceride crystallize in different crystalline forms (α, β, β’)

•Form α (vitreous state):
• appears when the fat solidifies by a quick method.
• the crystals formed are of the hexagonal type and are organized randomly
in space.
•Form β:
• it occurs when the cooling is slow or if the tempering is carried out at a
temperature slightly below the melting point, this form being the most
stable of all.
• in the β form, tricyclic crystals are formed oriented in the same direction.
• the β form is typical of palm oil, peanut, corn, coconut, sunflower, olive
and lard.
•Form β’:
• it is produced from the tempering above the melting point of the α form.
• in the β-form, orthorhombic crystals are formed which are oriented in
opposite directions.
• the β’form is typical of modified partial cottonseed oil, fats, fats and
modified lard.
Both α, β and β’form have a melting point, an X-ray diffusion pattern and a
refractive index.

Melting point
• The melting point of a fat corresponds to the melting
point of the β form which is the most stable polymorphic
form and is the temperature at which all the solids melt.
• When short chain or unsaturated acids are present, the
melting point is reduced.
• The melting point is of great importance in the
processing of animal fats.
• The melting points of pure fats are very precise, but
since fats or oils are made up of a mixture of lipids with
different melting points we have to refer to the melting
zone which is defined as the melting point of the fat
component. the fat that melts at a higher temperature.

Viscosity
• The viscosity of a fat is due to the internal friction
between the lipids that constitute it. It is generally
high due to the high number of molecules that make
up a fat.
• By increasing the degree of unsaturation the
viscosity decreases and when the length of the
chain increases the fatty acids components also
increases the viscosity.

Refractive index
• The refractive index of a substance is defined as the
ratio between the speed of light in air and in matter
(oil or fat) that is analyzed.
• Increasing the degree of unsaturation increases the
refractive index and when the length of the chain
increases, the refractive index also increases and that
is why it is used to control the hydrogenation
process.
• As the temperature increases, the refractive index
decreases.
• The refractive index is characteristic of each oil and
fat, which helps us to perform a quality control on

Density
• This physical property is of great importance when it
comes to designing equipment to process grease.
• Density decreases when fats dilate when going from
solid to liquid
• When the fats melt, their volume increases and therefore
the density decreases.
• For the control of percentages of solid and liquid in
commercial fat, dilatometric curves are used.

Solubility
• Solubility has great relevance in the processing of fats.
• Fats are fully soluble in non polar organic solvents (benzene, hexane etc.)
• Except for phospholipids, they are completely insoluble in polar solvents
(water, acetonitrile). They are partially soluble in solvents of intermediate
polarity (alcohol, acetone)
• The solubility of fats in organic solvents decreases with increasing chain
length and degree of saturation.
• Phospholipids can interact with water because the phosphoric acid and the
alcohols that compose them have hydrophilic groups.
• Generally the surface tension increases with the length of the chain and
decreases with temperature. Surface tension and interfacial tension decrease
with ease with the use of surfactant agents such as monoglycerides and
phospholipids.

Plasticity
• It is the property that has a body to preserve its shape
by resisting a certain pressure.
• The plasticity of a fat is caused by the presence of a
three-dimensional network of crystals inside which
liquid fat is immobilized.
• For a grease to be plastic and extensible there must be a
ratio between the solid and liquid part (20 -40% solid
state fat), the nets must not be tight and their crystals
must be in α form.
• The plastic fats act as a solid until the deforming forces
that are applied break the crystal lattice and the grease
passes to behave like a viscous liquid and therefore can
be smeared.

Emulsifying capacity
The emulsifying capacity is the capacity in the
water/ oil interface allowing the formation of
emulsion

FACTORS AFFECTING PHYSICAL
CHARACTERISTICS OF FATS AND OILS
1. Degree of Unsaturation of Fats and Oils
Food fats and oils are made up of triglyceride molecules which may
contain both saturated and unsaturated fatty acids.
The fatty acids that combine to make up triglycerides will vary;
therefore, triglycerides can contain all saturated fatty acids, all
unsaturated fatty acids or a mixture of both saturated and
unsaturated fatty acids.
Depending on the type of fatty acids combined in the molecule,
triglycerides can be classified as mono- or di-, -saturated
(alternatively mono- or di- unsaturated), tri-saturated and tri-
unsaturated

Generally speaking, fats that are liquid at room temperature tend to be
more unsaturated than those that appear to be solid, but there are
exceptions.
For example, coconut oil has a high level of saturates, but many are of
low molecular weight, hence this oil melts at or near room
temperature.
Thus, the physical state of the fat does not necessarily indicate the
amount of un-saturation.
The degree of un-saturation of a fat, i.e., the number of double bonds
present, normally is expressed in terms of the iodine value (IV) of the
fat.
IV is the number of grams of iodine which will react with the double
bonds in 100 grams of fat and may be calculated from the fatty acid
composition.
The typical IV for soybean oil is 123-139, for cottonseed oil 98-110, and
for butterfat it is 25-42.

2. Length of Carbon Chains in Fatty Acids
• The melting properties of triglycerides are related to those of their
fatty acids. As the chain length of a saturated fatty acid increases,
the melting point also increases.
• Thus, a short chain saturated fatty acid such as butyric acid has a
lower melting point than saturated fatty acids with longer chains.
• This explains why coconut oil, which contains almost 90%
saturated fatty acids but with a high proportion of relatively short
chain low melting fatty acids, is a clear liquid at 80°F while lard,
which contains only about 42% saturates, most with longer
chains, is semi-solid at 80°F.
Factors affecting physical properties of fats and oils- Continues

3. Isomeric Forms of Fatty Acids
For a given fatty acid chain length, saturated fatty acids
will have higher melting points than those that are
unsaturated.
The melting points of unsaturated fatty acids are
profoundly affected by the position and conformation of
double bonds. For example, the monounsaturated fatty
acid oleic acid and its geometric isomer elaidic acid have
different melting points.
Oleic acid is liquid at temperatures considerably below
room temperature, whereas elaidic acid is solid even at
temperatures above room temperature.

4. Molecular Configuration of Triglycerides
The molecular configuration of triglycerides can also affect the
properties of fats. Melting points vary in sharpness depending on the
number of different chemical entities present. Simple triglycerides
have sharp melting points while triglyceride mixtures like lard and
most vegetable shortenings have broad melting ranges.
In cocoa butter, palmitic (P), stearic (S), and oleic (O) acids are
combined in two predominant triglyceride forms (POS and SOS),
giving cocoa butter its sharp melting point just slightly below body
temperature. This melting pattern partially accounts for the pleasant
eating quality of chocolate.
A mixture of several triglycerides has a lower melting point than would
be predicted for the mixture based on the melting points of the
individual components and will have a broader melting range than any
of its components. Monoglycerides and diglycerides have higher
melting points than triglycerides with a similar fatty acid composition.

5. Polymorphism of Fats
Solidified fats often exhibit polymorphism, i.e., they can
exist in several different crystalline forms, depending on
the manner in which the molecules orient themselves in
the solid state.
The crystal form of the fat has a marked effect on the
melting point and the performance of the fat in the
various applications in which it is utilized.
The crystal forms of fats can transform from lower
melting to successively higher melting modifications.
The order of this transformation is:
Alpha ➝ Beta Prime ➝ Beta

The rate and extent of transformation are governed by the
molecular composition and configuration of the fat,
crystallization conditions, and the temperature and duration
of storage.
In general, fats containing diverse assortments of molecules
with varying fatty acids or fatty acids locations tend to
remain indefinitely in lower melting crystal forms (i.e. Beta
Prime), whereas fats containing a relatively limited
assortment of these types of molecules transform readily to
higher melting crystal forms (i.e. Beta).
Mechanical and thermal agitation during processing and
storage at elevated temperatures tends to accelerate the rate
of crystal transformation.
5. Polymorphism of Fats Continues……

Chemical properties of fats and oils

continues…….
It may be defined as number of mg of KOH needed to saponify the 1 g of
fat or oil

continues…….

Nutritional properties of fats and oils

Functional properties of fats and oils

Types of changes in fats and oils

CHEMICAL REACTIONS OF FATS AND OILS
1. Hydrolysis of Fats
Like other esters, glycerides can be hydrolyzed readily. Partial
hydrolysis of triglycerides will yield mono- and diglycerides and
free fatty acids.
When hydrolysis is carried to completion with water in the
presence of an acid catalyst, the mono-, di-, and triglycerides will
hydrolyze to yield glycerol and free fatty acids.
With aqueous sodium hydroxide, glycerol and the sodium salts of
the component fatty acids (soaps) are obtained. This process is
also called saponification.
In the digestive tracts of humans and animals and in bacteria, fats
are hydrolyzed by enzymes (lipases). Lipolytic enzymes are
present in some edible oil sources (i.e., palm fruit, coconut). Any
residues of these lipolytic enzymes (present in some crude fats
and oils) are deactivated by the elevated temperatures normally
used in oil processing.

Hydrolysis by acid
Hydrolysis by alkali

2. Oxidation of Fats
Autoxidation. Of particular interest in the food arena is the process
of oxidation induced by air at room temperature referred to as
“autoxidation”. Ordinarily, this is a slow process which occurs only
to a limited degree. However, factors such as the presence of light
can increase the rate of oxidation.
In autoxidation, oxygen reacts with unsaturated fatty acids at the
double bond site. Initially, peroxides are formed which may break
down into secondary oxidation products (hydrocarbons, ketones,
aldehydes, and smaller amounts of epoxides and alcohols).
Metals, such as copper or iron, present at low levels in fats and oils
can also promote autoxidation. Fats and oils are normally treated
with chelating agents such as citric acid to complex these trace
metals (thus inactivating their prooxidant effect).

The result of the autoxidation of fats and oils is the development of
objectionable flavors and odors characteristic of the condition
known as “oxidative rancidity”.
Some fats resist this change to a remarkable extent while others
are more susceptible depending on certain factors, such as the
degree of unsaturation.

When rancidity has progressed significantly, it
becomes readily apparent from the flavor and
odor of the oil. Expert tasters are able to
detect the development of rancidity in its
early stages.
The peroxide value determination, if used
judiciously, is oftentimes helpful in measuring
the degree to which oxidative rancidity in the
fat has progressed.

Oxidation at Higher Temperatures
Although the rate of oxidation is greatly accelerated at higher temperatures,
oxidative reactions which occur at higher temperatures may not follow
precisely the same routes and mechanisms as the reactions at room
temperature.
Thus, differences in the stability of fats and oils often become more apparent
when the fats are used for frying or slow baking. The stability of a fat or oil
may be predicted to some degree by determining the oxidative stability index
(OSI).
The more unsaturated the fat or oil, the greater will be its susceptibility to
oxidative rancidity. Predominantly unsaturated oils (i.e., soybean,
cottonseed, or corn) are less stable than predominantly saturated oils (i.e.,
coconut oil, palm oil).
Dimethyl silicone is usually added to institutional frying fats and oils to
reduce oxidation tendency and foaming at elevated temperatures.
Historically, partial hydrogenation has often been employed in the processing
of liquid vegetable oil to increase the stability and functionality of the oil.
The trend of utilizing partial hydrogenation has been declining during the last
decade due to developments in oils/fat processes and trans fat legislation.

Thermal degradation of triglycerides/fats/oils

Thermal degradation reaction of triglycerides/fats/oils

Photo-oxidation is an alternative mechanism that leads to formation of
hydroperoxides as a result of excitation state of lipid electrons (type I
photo-oxidation) or excitation state of oxygen electrons (type II photo-
oxidation).
Type I photo-oxidation – The reaction starts in the presence of light and
some sensitizers, such as riboflavin. It is a process by which a hydrogen
atom or an electron, transfer between an excited triplet sensitizer and a
substrate, such as PUFA, producing free radicals or free radical ions.
Type II photo-oxidation – Under this mechanism, environmental oxygen is
normally in the triplet electronic state, 3O2. It can be excited by light to
singlet oxygen in presence of a sensitizer, such as chlorophyll. Singlet
oxygen is1,500 times faster in reacting with unsaturated lipids than triplet
oxygen, which ultimately leads to forming hydroperoxides.
Another important way in which unsaturated lipids can be oxidized involves
exposure to light . In this process, oxygen becomes activated to the singlet
state by transfer of energy from the photosensitizer.

Edible oil is oxidized during processing and storage via autoxidation and
photosensitized oxidation, in which triplet oxygen (3O2) and singlet oxygen (1O2)
react with the oil, respectively.
Autoxidation of oils requires radical forms of acylglycerols, whereas photosensitized
oxidation does not require lipid radicals since 1O2 reacts directly with double bonds.
Lipid hydroperoxides formed by 3O2 are conjugated dienes, whereas 1O2 produces
both conjugated and nonconjugated dienes.
The hydroperoxides are decomposed to produce off-flavor compounds and the oil
quality decreases. Autoxidation of oil is accelerated by the presence of free fatty
acids, mono- and diacylglycerols, metals such as iron, and thermally oxidized
compounds.
Chlorophylls and phenolic compounds decrease the autoxidation of oil in the dark,
and carotenoids, tocopherols, and phospholipids demonstrate both antioxidant and
prooxidant activity depending on the oil system.
In photosensitized oxidation chlorophyll acts as a photosensitizer for the formation of
1O2; however, carotenoids and tocopherols decrease the oxidation through 1O2
quenching.
Temperature, light, oxygen concentration, oil processing, and fatty acid composition
also affect the oxidative stability of edible oil.

Autoxidation of oils, free radical chain reaction, includes
initiation, propagation, and termination steps:
Initiation
RH → R· + H·
Propagation
R· + 3O2 → ROO· ROO· + RH → ROOH + R·
Termination
ROO· + R· → ROOR R· + R· → RR
(R : lipid alkyl)

3. Polymerization of Fats
All commonly used fats and particularly those high in
polyunsaturated fatty acids tend to form larger molecules (known
broadly as polymers) when heated under extreme conditions of
temperature and time. Under normal processing and cooking
conditions, polymers are formed.
It is believed that polymers in fats and oils arise by formation of
either carbon-to-carbon bonds or oxygen bridges between
molecules. When an appreciable amount of polymer is present,
there is a marked increase in viscosity.

4. Reactions during Heating and Cooking
Glycerides are subject to chemical reactions (oxidation, hydrolysis,
and polymerization) which can occur particularly during deep fat
frying.
The extent of these reactions, which may be reflected by a
decrease in iodine value of the fat and an increase in free fatty
acids, depends on the frying conditions (principally the
temperature, aeration, moisture, and duration).
The composition of a frying medium also may be affected by the
kind of food being fried. For example, when frying foods such as
chicken, some fat from the food will be rendered and blended with
the frying medium while some of the frying medium will be
absorbed by the food.
In this manner the fatty acid composition of the frying medium will
change as frying progresses. Since absorption of frying medium
into the food may be extensive, it is often necessary to replenish
the fryer with fresh frying medium. Obviously, this replacement
with fresh medium tends to dilute overall compositional changes of
the fat that would have taken place during prolonged frying.

The smoke, flash, and fire points of a fatty material are standard
measures of its thermal stability when heated in contact with air.
The “smoke point” is the temperature at which smoke is first
detected in a laboratory apparatus protected from drafts and
provided with special illumination. The temperature at which the
fat smokes freely is usually somewhat higher.
The “flash point” is the temperature at which the volatile
products are evolved at such a rate that they are capable of
being ignited but not capable of supporting combustion.
The “fire point” is the temperature at which the volatile products
will support continued combustion.
For typical non-lauric oils with a free fatty acid content of about
0.05%, the “smoke”, “flash”, and “fire” points are around 420°F,
620°F, and 670°F respectively.

The degree of unsaturation of an oil has little, if any, effect on its
smoke, flash, or fire points.
Oils containing fatty acids of low molecular weight such as
coconut oil, however, have lower smoke, flash, and fire points
than other animal or vegetable fats of comparable free fatty acid
content.
Oils subjected to extended use will have increased free fatty acid
contents resulting in a lowering of the smoke, flash, and fire
points.
Accordingly, used oil freshened with new oil will show increased
smoke, flash, and fire points.

Lipid oxidation is a highly complex set of free radical
reactions between fatty acids and oxygen, which results
in oxidative degradation of lipids, also known as
rancidity.
Lipid oxidation intermediate products (free radicals) and
end products (reactive aldehydes) may interact with
other food constituents, such as proteins, sugars,
pigments, and vitamins, and negatively modify their
properties.
The reaction mechanisms and the rate of lipid oxidation
depend on many factors, such as fatty acid composition,
the presence of prooxidants and antioxidants, type of
lipid (triacylglycerols, phospholipids, and others), and
LIPID OXIDATION

Factors affecting development of oxidation
• Fatty acid compositions- SFA, MUFA or PUFA
• Oxygen, free radicals
• Pro-oxidants
• Antioxidants and additives
• Processing conditions
• Storage time and conditions

• The first carbon following the carboxyl carbon is
the alpha carbon
• The second carbon following the carboxyl carbon
is the beta carbon.
• The last carbon in the chain, farthest from the
carboxyl group, is the omega carbon.

Salient features of Beta oxidation

Inhibition of oxidation reactions

Oil based antioxidants
Bioactive minor components present in Edible oils
 tocopherols – almost all vegetable oil
 tocotrienols- palm oil, rice bran oil, wheat germ oil
 Omega-3 fatty acids- linseed oil, canola oil, soybean oil
 Carotenoids- palm oil
 lecithin- soybean oil
 Oryzanols- rice bran oil
 lignans- linseed oil, sesame oil
 phytosterols and phytostanols- olive oil, canola oil, sesame oil, rice
bran oil

Measurement methods of oxidative rancidity

• A variety of fatty acids exists in the diet of humans, in the
bloodstream of humans, and in cells and tissues of
humans
• Fatty acids are energy sources and membrane
constituents. They have biological activities that act to
influence cell and tissue metabolism, function, and
responsiveness to hormonal and other signals.
• The biological activities may be grouped as regulation of
membrane structure and function; regulation of
intracellular signaling pathways, transcription factor
activity, and gene expression; and regulation of the
production of bioactive lipid mediators.
• Fatty acids influence health, well-being, and disease risk
through various biological activities

• Although traditionally most interest in the health impact of
fatty acids related to cardiovascular disease and clear that
fatty acids influence a range of other diseases however its
evident through various studies that fats play important
role in metabolic diseases such as type 2 diabetes,
inflammatory diseases, and cancer.
• Scientists, regulators, and communicators have described
the biological effects and the health impacts of fatty acids
according to type of fatty acid. However, it is now obvious
that within any fatty acid class, different fatty acids have
different actions and effects.

• Palm oil, coconut oil, cocoa butter, and animal-derived
fats such as lard, tallow, and butter are rich sources of
saturated fatty acids, although the amounts of
individual saturated fatty acids present vary among
these sources.
• Many plant oils contain a significant amount of
saturated fatty acids, particularly palmitic acid.
• Saturated fatty acids are also synthesized de novo in
humans, the precursor being acetyl-CoA produced from
carbohydrate or amino acid metabolism.
Effects of Saturated Fatty Acids on Human Health

• Many cell membrane phospholipids contain significant
proportions of palmitic and stearic acids; neural cell
membrane phospholipids contain some longer chain
saturated fatty acids. Ceramides and sphingolipids can
be rich in saturated fatty acids, while gangliosides are
often very rich in stearic acid.
• Stearic acid shares some but not all properties with
myristic and palmitic acids, while the milk fat–derived
odd-chain saturated fatty acids (pentadecanoic and
heptadecanoic) are associated with lower risk of type 2
diabetes, CHD, and CVD. It becomes evident when
considering these findings that not all saturated fatty
acids have the same effects on human health, most likely
because each type of saturated fatty acid has unique
effects on cells and tissues.

Effects of cis MUFAs on Human Health
• Oleic acid (18:1ω-9) is the most prevalent cis MUFA in the human
diet, and in many individuals, it is the most prevalent dietary fatty
acid. It is widespread in foods.
• Olive oil is an especially rich source, with oleic acid typically
contributing about 70% of fatty acids present. Low–erucic acid
rapeseed oil (aka canola oil) typically contains about 60% of fatty
acids as oleic acid, while “high oleic” varieties of normally linoleic
acid–rich oils such as sunflower oil are now available.
• Dairy fats contain oleic acid and also vaccenic acid (18:1ω-7). Both
palmitoleic and oleic acids can be synthesized de novo in humans,
by Δ9-desaturation of palmitic and stearic acids, respectively.
• Many cell membrane phospholipids contain significant proportions
of oleic acid and some palmitoleic acid.

Effects of cis MUFAs on Human Health
• Studies have reported that replacing saturated fatty
acids with oleic acid has a small cholesterol and LDL
cholesterol–lowering effect with an inconsistent effect on
HDL cholesterol.
• Decreased peroxidizability of lipoprotein and cell
membrane oleic acid compared with PUFAs would be
expected to limit inflammation, because oxidative stress
is proinflammatory.

• Coconut oil is 100% fat, 80-90% of which
is saturated fat. This gives it a firm texture
at cold or room temperatures.
• Fat is made up of smaller molecules called
fatty acids, and there are several types of
saturated fatty acids in coconut oil.
• The predominant type is lauric acid (47%),
with myristic and palmitic acids present in
smaller amounts, which have been shown
in research to raise harmful LDL levels.
• Also present in trace amounts
are Monounsaturated and polyunsaturated
fats.

• Coconut oil contains no cholesterol, no fiber,
and only traces of vitamins, minerals, and plant
sterols.
• Plant sterols have a chemical structure that
mimics blood cholesterol, and may help to block
the absorption of cholesterol in the body.
• However, the amount found in a few tablespoons
of coconut oil is too small to produce a
beneficial effect.
• coconut oil made of 100% medium-chain
triglycerides (MCTs)
• MCTs have a shorter chemical structure than
other fats, and so are quickly absorbed and
used by the body. After digestion, MCTs travel to

Virgin or Extra Virgin (interchangeable terms): If using a “dry” method, the fresh
coconut meat of mature coconuts is dried quickly with a small amount of heat,
and then pressed with a machine to remove the oil. If using a “wet” method, a
machine presses fresh coconut meat to yield milk and oil. The milk is separated
from the oil by fermentation, enzymes, or centrifuge machines. The resulting oil
has a smoke point of about 350 degrees Fahrenheit (F), which can be used for
quick sautéing or baking but is not appropriate for very high heat such as deep-
frying.
•Expeller-pressed—A machine presses the oil from coconut flesh, often with the
use of steam or heat.
•Cold-pressed—The oil is pressed without use of heat. The temperature remains
below 120 degrees F this is believed to help retain more nutrients.

Virgin coconut oil is defined as oil extracted from fresh
coconut meat and processed using physical and natural
processes (Codex alimentarius, 1999). There is no prior
drying (e.g., use of copra), refining or chemical reactions
before the oil is extracted from coconut meal by
mechanical means (expelling, pressing, heating,
washing, settling, filtration, and centrifugation).
aqueous extraction of coconut oil with added exogenous
enzymes (proteases, amylases, polyglacturonases,
cellulases, pectinases or combinations of enzymes)
achieving oil yields ranging from 12–80% from fresh or
dried coconut meat.

•Refined: The copra is machine-pressed to release the oil.
The oil is then steamed or heated to deodorize the oil and
“bleached” by filtering through clays to remove impurities
and any remaining bacteria. Sometimes chemical solvents
such as hexane may be used to extract oil from the copra.
The resulting oil has a higher smoke point at about 400-450
degrees F, and is flavorless and odorless.
•Partially Hydrogenated: The small amount of unsaturated
fats in coconut oil is hydrogenated or partially
hydrogenated to extend shelf life and help maintain its solid
texture in warm temperatures. This process creates trans
fats, which should be avoided.

Common name Fatty acid Percentage
Caproic acid 6:0 0.2–0.5
Caprylic acid 8:0 5.4–9.5
Capric acid 10:0 4.5–9.7
Lauric acid 12:0 44.1–51
Myristic acid 14:0 13.1–18.5
Palmitic acid 16:0 7.5–10.5
Stearic acid 18:0 1.0–3.2
Arachidic acid 20:0 0.2–1.5
Oleic acid 18:1n-9 5.0–8.2
Linoleic acid 18:2n-6 1.0–2.6

Products
Canned coconut milk (light and nonlight, with and without
added emulsifiers) may be the basis of some savory sauces,
especially those that are Asian-based.
Coconut cream is coconut “milk” with more fat, less water
and generally a greater coconut taste. Coconut “milk” is
produced when the “meat” of a coconut is cooked, and then
the meat is strained.
Coconut water is the “juice” that flows from a newly cracked
coconut.
Coconut “meat” is the interior of the coconut that is often
shredded and sweetened; however, unsweetened varieties
may be available.

The use of these coconut products also adds
some texture to some formulations and recipes
due to the fat in the coconuts, and to the dried,
shredded consistency of the coconut meat.
So for taste, texture and interest, a small
amount of coconut and/or its products may be
helpful additions.

Cottonseed contains hull and kernel. The hull produces fibre
and linters. The kernel contains oil, protein, carbohydrate
and other constituents such as vitamins, minerals, lecithin,
sterols etc.
Cottonseed oil is extracted from cottonseed kernel.
Cottonseed oil, also termed as "Heart Oil" is among the most
unsaturated edible oils.
Cottonseed oil quality utilization and processing Refined and
deodorised cottonseed oil is considered as one of the purest
cooking medium available.
An additional benefit that accrues from Cottonseed Oil is its
high level of antioxidants - tocopherols.

Fatty acid composition of different cotton seed oil

Tocopherol content of various oils

Various processes involved in deterioration

Toxic elements- cottonseed pigments
Cottonseed contains gassypurpurin, gossycaerulin, gossyfulivin, gossyverdurin
and gossypol. Gossypol is yellow, gossypurpurin - purple, gossyfulvin - orange,
gossycaerulin-blue and gossyverduin- green.
The gossypol content is greater in raw material than in cooked cottonseed,
whereas gossypupurin and gossyfulvin are found in higher proportion in cooked
seed. Gossypol.is the most important pigment present in the cottonseed and
create enormous problem of seed processing and utilisation of cottonseed as
by-product. Gossypol is located all over in plant. It gives undesirable colour to
the oil and reacts with protein to reduce the nutritive value of cottonseed
product. It is toxic to non-ruminant animal. Several new processes and solvents
have been tried to remove the pigment from cottonseed so that it can be used
for edible purposes without any adverse effect.
Gossypol is in the free state in the whole seed and on cooking of cottonseed
forms "bound gossypol" as a result of gossypol combining with either free
amino or free carboxy groups of cottonseed protein. Bound gossypol decreases
the nutritive value of protein and availability of lysine, an essential amino acid.

In India entire cottonseed oil produced is utilised for edible purposes, mostly
for vanaspati, only small quantity (5-10%) is used for manufacturing soaps.

Central Institute for Research on Cotton Technology
(CIRCOT), Mumbai to develop efficient oil extraction
protocols and also to test their techno-economic feasibility.
Efforts are being made to identify suitable antifoaming
agent along with its optimum concentration for preserving
quality of frying oil for longer duration under Indian
cooking habits.
To create awareness and to promote widespread
consumption, work is being carried out towards exploring
novel culinary applications also.

Steps involved in processing of cottonseed oils

Technology of fats and oil (B.Tech Food Technology)

Technology of fats and oil (B.Tech Food Technology)

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