2. Topics under unit 2 ...
• Extraction ,purification ,preservation and
storage of fish oils
• Industrial and nutritional applications of fish
oils
• Vitamin A and vitamin D
3. INTRODUCTION
The total world fisheries and
aquaculture production was 171
million tons in 2016 in which 21.7
million tons are used for fish oil and
fish meal.
Peru and Chile are the largest
producer of fish oil.
Norway is the largest global importer
of fish oil.
4. Fish oil is oil derived from the
tissues of oily fish.
They are described as flesh oil,liver
oil, or oil of the whole fish.
Fish oil contain omega-3
polyunsaturated fatty acids.
They act as a precursors and reduce
the inflammation of the body.
5. HISTORY
• The variants of fish oil include cod liver
oil and other compounds that were
produced in England during the time of
the Industrial revolution
• In the 1970s, investigators discovered that
Eskimos, particularly Greenland and other
population, such as the Japanese, had very
low rates of myocardial infraction and
other coronary events, despite consuming
large amounts of derived fish .
6. • That led to articles and studies in the
1990s claiming that if people took fish oil
pills health of heart would improve.
• Soon the effects of the fish oil pills
become exaggerated , and they were
touted as miracle pills.
7. Chemical composition of fish oil
• Saturated fatty acid – 25%
• Unsaturated fatty acid -75%
• Cholesterol - very low.
9. Extraction
• Dry rendering process
• Wet rendering process
• Supercritical fluid extraction
• Extraction by fish silage
• Extraction using solvents
10. Dry rendering process
• The raw material is dried to a moisture
content of 10% and pulverised.
• They are operated at atmospheric pressure
or under partial vaccum.
• The resultant dry cake is then pressed to
remove any oil.
11.
12. Wet rendering process
• The process consists of
grinding,cooking,pressing, separating and
drying,packing the meal.
• Centrifuging the press liquor to remove
suspended particles and to separate oil and
concentrating the stick water
13.
14. • Press liquor seperation
• It is passed over an vibrating screen(5-
6mm)to remove the coarse particles.
• Decanter can be used to obtain the oil and
water phase suitable for further separation
• It is centrifuged for separation into oil and
stick water.
• The oil is pumped to a polishing centrifuge
and the stick water to the evaporator.
16. Supercritical fluid extraction
• Using solvents to extract the oil
• SF- lower viscosity & high diffusivity- mass
transfer- reduce the time for extraction
• Higher cost
• Mainly CO2
• Conventional process to obtain oils rich in
PUFA and with a reduced content of
contaminants
17. Extraction using solvents
• Based on solubility of lipids in organic solvents
and their insolubility in water
• disadvantages- requires relatively dry sample,
long time, generating large amount of residual
sample
• Generally applied for analytical purpose but
not for an industrial purpose
• Several methods vary according to the type of
solvent
18. Extraction by fish silage
• Fish silage is a semi-liquid product made from
whole fish or part of fish, to which acids,
enzymes or lactic acid bacteria are added,
causing protein hydrolysis
• Good alternative to traditional methods
• Physicochemical and microbialogical changes
caused can’t only improve extraction but also
prevent undesirable process i.e. Fat oxidation
19. Traditional methods for Cod liver oil
extraction
• 1. laying tree branches over a kettle of water,
and fresh livers are laid over the branches.the
water was brought to boil & as steam rose,
the oil from the liver dripped into the water
and was skimmed off
• 2.Livers placed in barrels to rot, with the oil
skimmed off over the season
23. Preservation & storage
• Fish oil is highly susceptibility to oxidation. So
some of the antioxidants used in fish oil for
preservation
• Fish oil should be stored in cool, dark place,
away from sunlight and oxygen free
environment
• First fish oils stored in wooden boxes now in
recent times oil storage containers are used
24. Industrial applications
• Refined fish oils are rich in polyunsaturated fatty
acids of the linolenic(omega – 3) acid family
• The highly unsaturated properties make the oils
suitable for a number of technical applications,
particularly as drying oils and varnishes
• Used in metallic soaps, lubricating greases and
waterproofing agents
• Small quantities of fatty acids are used
pharmaceutically and medicinally, and for
scientific research purposes
25. Nutritional application
• Fish oil helps with cholesterol by lowering levels
of LDL while increasing levels of HDL
• Fish oil can benefit the heart because the EPA and
DHA that make up the supplement helps to
prevent plaque deposits and blood clots inside
arteries.
• Fish oil improves the ability of muscle cells to
take up glucose in the presence of insulin. This
proves to be beneficial to those with type II
diabetes
26. • Fish oil is most often used for condition
related to heart and blood system .
• It is used to prevent the heart disease or
stroke , as well as for clogged arteries , chest
pain , irregular heartbeat.
• It is used in many kidney related problems
including kidney disease.
• Fish oil is used as brain food to help
depression, bipolar disorder, psychosis.
27. Vitamin A
• Retinol
• Vitamin A rich in cod liver oil
• Main function is Produce pigments in the
retina of eye other functions are formation
and maintenance of teeth, bones, soft tissue
etc
• Deficiency - nyctalopia
28. Vitamin D
• Cholciferol
• Shark liver oil and cod liver oil have more
amount of vitamin D
• Maintain the health of bones. Support the
immune system, brain, and nervous system
• Regulate the insulin levels and aid diabetes
management
• Main deficiency - rickets
