Processing of fish products

1. FISH PRODUCTSFISH PRODUCTS
Mrs.R.Sinthiya
Assistant Professor
Department of Food Processing and
Preservation Technology
Faculty of Engineering
Avinashilingam Institute for Home Science &
Higher Education for Women University,
Coimbatore

2. Smoking Fish
Freezing Fish
Dried Fish
Canned Fish
Fish Oil

3. Smoking of fishSmoking of fish
 Splitting and cleaning
Salting
Hanging
Smoking
Packaging

4. Splitting and cleaningSplitting and cleaning
The fish is split and the gut,gills are
removed
Then they are cleaned with water

5. SaltingSalting
The cleaned fish is then soaked in
brine solution
Duration of treatment with brine
depends up on the strength of the
brine solution
The brine is stored at a temperature
of 52 to 55 degree C and is changed
atleast once a day

6. HangingHanging
The salted fish is hung in the kiln on
a rack for dipping
The protein which has dissolved in
the salt form a sticky solution on the
surface of the fish
Which gives the skin a glossy
appearance which is one of the
commercial criteria of the quality

7. SmokingSmoking
Two types of smoking
• Hot Smoking process
• Cold Smoking process

8. The Hot Smoking ProcessThe Hot Smoking Process
 The smoking time will vary as well depending
on the size of the fish and the conditions for
the marketing of the products but will usually
be 1-2 hours.
 The fish is dried for a period before smoking
in order to prepare the skin for the reception
of the smoke
 The fish could be lightly salted or not be
salted at all before smoking, sometimes a
sprinkle of salt is given when packed in boxes
after smoking

9. The equipment for the hot smoking
process has developed from the most
simple chimney/barrel to specially
designed cabinets with inbuilt devises
for the control of the smoking process
but it is characteristic that the very
primitive equipment persists.

10. During cooking process it loosesits
weight
If the fish is packed hot it may
develop a moist,flabby appearance
sand mould growth may occur

12. The Cold Smoking ProcessThe Cold Smoking Process
 The characteristic feature for cold smoked
fish will be that the flesh does not appear
cooked
 Most cold smoked fish are smoked as fillets
 The fish could be exposed to smoke for an
extended period of 24 hours or more in a
smoking cabinet
 However the time is shortened considerably
in the modern cold smoking process to
approach the times known from the hot
smoking process.

13. Freezing of fishFreezing of fish
 Freezing extends the period of storage
and effective in keeping the fish in a
condition similar to the resh fish
 Three methods:
1.By direct contact between the fish and
a refrigerated metal plates
2.By blowing a continuous stream of
refrigerated air over the product
3.By immersing the fish in a low
temperature liquid

15. Dried fishDried fish
 The fish is prepared immediately after
capture
 After gutting the fish, it is either dried
whole, or split along the spine leaving the
tail connected.
 Stable cool weather protects the fish from
insects and prevents bacterial growth.
 Too much frost will spoil the fish, as ice
destroys the fibers in the fish.

16.  After its three months hanging on the
flakes, the fish is then matured for another
two to three months indoors in a dry and
airy environment
 During the drying, about 80% of the water
in the fish disappears
 The stockfish retains all the nutrients from
the fresh fish, only concentrated: it is
therefore rich in proteins, vitamins, iron,
and calcium.

18. Canning of fish

19. 

20. Requirements Concerning RawRequirements Concerning Raw
MaterialsMaterials
Fish intended for canning should be
produced in accordance with the
appropriate Sections of this code

21. Storage of raw materialStorage of raw material
 Raw materials should be stored, as quickly as
possible after reception, in suitable premises
 Raw materials should be stored so that any
recontamination of final products, in-process
products or containers should be prevented
 All materials for containers or packages should
be stored in satisfactory clean and hygienic
conditions
 During loading, stowing and unloading of
empty containers, containers shouldn't be
stepped on. These precautions become more
imperative when cans are put in bags or on
pallets.

22. Unwrapping, UnpackingUnwrapping, Unpacking
During unwrapping and unpacking
operations, precautions should be
taken in order to limit product
contamination and foreign matters
introduction into the product.
To avoid microbial proliferation,
there should be no waiting periods
during these operations.

23. ThawingThawing
 Thawing time and temperature should be
selected to avoid conditions favourable
for development of microorganisms or
decomposition
 During thawing products should not be
exposed to excessively high temperatures
 After thawing should be immediately
processed or refrigerated and kept at the
adequate temperature (temperature of
melting ice).

24. Gutting and WashingGutting and Washing
 fish requiring gutting on arrival at the
plant should be gutted efficiently and with
care to avoid contamination
 gutting must be complete to remove
pieces of intestinal tract and internal
organs
 immediately after gutting, fish should be
washed with clean sea water or potable
water. After washing the fish should be
drained and properly iced

25. Pre-Cooking and Other Pre-Pre-Cooking and Other Pre-
TreatmentsTreatments
 There are several reasons for pre-cooking
fish or shellfish prior to canning:
- to lower the water content of the
flesh in order to avoid water exudation
during heat processing
- to give a particular flavour or texture
to the product
- in some cases, to prepare the
products for later treatments.

26. Packing in Cans (Filling,Packing in Cans (Filling,
Sealing and Coding)Sealing and Coding)
 Filling
- Containers and covers should be inspected
immediately before delivery to the filling
machines or packing tables to ensure that they
are clean, undamaged and without visible flaws
- Containers of canned fish should be filled
as directed in the scheduled process
- Mechanical or manual filling of containers
should be checked in order to comply with the
filling rate and the headspace specified in the
adopted sterilization schedule

27.  The necessary amount of headspace will
depend partly on the nature of the contents.
 The filling should also take into account the
heat processing method
 If fish has been brine-frozen or stored in
refrigerated brine, the amount of salt
absorbed should be taken into
consideration when salt is added to the
product for flavoring
 Excessive vacuum may cause the container
to panel, particularly if the headspace is
large, and may also cause contaminants

28. Filled containers should be
inspected
- to ensure that they have been
properly filled and will meet accepted
standards for weight of contents
- and to verify product quality and
workmanship just before they are
closed.

29. SealingSealing
 Sealing the container is one of the most
essential processes in canning
 The operation, maintenance, regular
inspection and adjustment of sealing
machines should received particular care.
 If vacuum is used during packing, it
should sufficient to prevent the containers
from bulging under any condition likely to
be encountered during the transport,
storage or marketing of the product.

30. This is useful for deep containers or
glass containers.
It is difficult and hardly necessary to
create a vacuum in shallow
containers that have relatively large
flexible covers.

31. Handling of Containers AfterHandling of Containers After
Closure - Waiting Before HeatClosure - Waiting Before Heat
ProcessingProcessing
 Containers after closure should always be
handled carefully in such a way as to
prevent every damage capable to
determine defects and microbiological
recontamination
 Filled and sealed metal containers should
be thoroughly washed before heat
processing to remove grease, dirt and fish
or shellfish marks on their outside walls

32. the filled and sealed containers must
be held for a long time before heat
processing, refrigeration or heat
holding (> 63°C) for fish soups, for
example, are necessary

33. Heat Processing andHeat Processing and
CoolingCooling
Heat processing is one of the most
essential operations in canning
1. Sterilization Schedule
2. Heat Processing Operation
3. Cooling

34. Labeling, Casing and Storage ofLabeling, Casing and Storage of
Finished ProductsFinished Products
 The materials used for labelling and
casing canned fish and shellfish should
not be conducive to corrosion of the
container
 Code marks appearing on containers of
canned fish and shellfish should also be
shown on the cases in which they are
packed
 Canned fish and shellfish should be so
stored that they will be kept dry and not
exposed to extremes of temperature