2. Salting
The method is called salting
when salt is the only means of
preservation.
Salting is usually applied in
combination with other
methods of preservation such
as drying, smoking, fermenting,
canning and marinating.
Salting is one of the earliest
techniques for preserving fish.
Salting preserves by lowering
the moisture content of the fish
to the point where bacterial and
enzymatic activities are
retarded.
Salt removes water from the
fish by osmosis.
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3. Salt QualityThe quality and type of salt are of prime importance when salting fish since they
will have a great effect on the quality of the end product.
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5. Chemical composition
- Pure common salt is 99.9%
sodium chloride(NaCl),
however , many commercial
salts contain a number of
impurities. Apart from
contaminants such as sand,
dust, mud and moisture.
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7. Microbiological spoilage
- Spoilage bacteria are
inhibited by salt, but some
tolerant bacteria (halophiles)
are often found in many
commercial salts.
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9. Physical properties
- Salt comes in a variety of
grain sizes depending on the
number of grinding steps that
it has undergone. Salts
should be reasonably small
grain size to facilitate close
contact with the fish surfaces
and rapid dissolution.
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10. 1.Fine grain salt
- Is suitable for brine
preparation because it
dissolves quickly and easily.
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11. 2. Small grain salt
- Small grain act too qickly on
the surface of the fish and
remove moisture so rapidly.
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12. Factors affecting
salt penetration.
1. Fat and protein content
- The higher the fat content , the slower the salt
uptake. Fat acts as the barrier both to the entry
of salt and withdrawal of moisture.
2. Thickness of the flesh
- The thicker the flesh, the slower the diffusion of
salt to the center.
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13. 3. Purity of salt
- The purer the salt, the
faster the salt
penetration.
-The presence of
impurities such as calcium
and magnesium chlorides
and sulfates, even in small
amounts reduce the rate of
salt penetration into the
flesh.
4. Temperature during
salting
- Salt uptake is faster at
higher temperatures but
the rate of bacterial
spoilage is also
accelerated.
5. Freshness of fish.
- The fresher the fish, the
more slowly salt will be
taken up.
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14. Methods of salting
1. Dry salting or kench process
- This method is carried out by rubbing fish with salt just before
packing and each layer of fish is sprinkled with salt. Water
removed by salt is allow to drain.
2. Wet salting
- Wet salting can be brining or pivkle curing. In wet salting, brining
is done by placing fish in a solution of salt and water until the
desired salt concentration is attained in fish.
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20. Salting procedure
1.Raw material
- Fresh raw material must be used for salting.
2. Preparation of raw material
- Big fish are scaled and the skin of tough-skinned
fish is removed.
- 3. Salting process
- - if te fish will be brine- salted, first soak the fish in
brine of lesser concentration for about one half to
one hour to leach the blood before packaging in
the saturated brine.
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22. Materials and procedure
Small shrimp
(alamang)
Salt
Mortar and pestle
Polyehtylene bags
Drying trays
Plastic bowls
Banana leaves
1. Remove adhering
materials from
shrimp. Wash
thoroughly by
placing them in a
woven basket and
dipping in clean
seawater several
times.
2. Partially dry the
shrimps for one day
to lower the moisture
content, by
spreading them
thinly on clean mats
or drying racks.
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3. Add salt to shrimp
(2:3) during tracing.
Tracing is done by
pounding the shrimp
– salt mass with
mortar and pestle.
After mixing, dry the
mass for one day.
4. Form into round
shape or cubes.
5. Package product
in clean banana
leaves or in low
density polyethylene
bags.
23. Spoilage of salted fish
1. Pink or reddening
This is the most common defect of salted and dried
fishery products which is caused by the presence of
some species of halophilic bacteria which have a
pink or rose color.
2. Dun
Dun is characterized by a peppering of light brown
spots or fawn spots. This spoilage is caused by
growth of molds of the wallemia genus.
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24. Spoilage of salted fish
3. Sliming
Slimy fish is caharacterized by a semi-greasy,
sticky, glistening layer of yellow-gray or beige color.
A sour pungent off-odor is usually manifested in the
product.
4. Souring
This condition is due to improper salting which
results to uneven distribution of slat throughout the
muscles of the fish.
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25. Spoilage of salted fish
5. Salt burn
This is due to excessive amount of fine salt that
draws out the surface moisture so rapidly that
protein coagulates to the extent that rehydration of
the salted product is difficult to attain.
6. Salt burn
This type of spoilage is somewhat related to sliming
during which degradative bacteria gain a hold when
the temperature is too high.
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