Chapter3 Chilling

CHAPTER3
CHILLING
By: ARMAN N. BERMON, LPT
Instructor 1

Fish alone among the major food
commodities is subject to virtually no control
before harvesting or catching.
Since fish is highly perishable, proper handling
must start from the moment it is harvested until
it reaches the consumer's table
 The fisher, the middleman (wholesaler and retailer) and the
consumer all have important roles in keeping fish as
fresh as possible.
Lowering the temperature (chilling, refrigeration
and freezing) is the key factor in maintaining
the quality of fresh fish.

Chilling is the most common practice in keeping the freshness of fish. Chilling
means the reduction of temperature to some point below (-1.1 to -2.2°C) or
above (0°C) the freezing point of the fish muscle.
Chilling does not stop spoilage but slows it down considerably.
Methods of Chilling:
There are several ways of chilling fish, but only the few
methods which are relevant in the fishing industry will be
discussed here.
1. Wet Ice (Icing)

Icing is by far the most common and useful way of chilling the fish
catch. Cooling is effected by the direct contact between the melted
ice and the fish.
When ice is placed in close contact with the fish, heat is
transferred from the warm fish to the ice resulting to the melting
of ice; in tum the fish is cooled down by the melted ice.

 considerations during icing the fish:
 Sufficient ice must be used to maintain fish temperature at 0°C.
For longer trips more ice than fish is needed, more than the usual
1: 1 ice : fish ratio.
The arrangement of ice and fish must be in such a way that
accumulated water, blood and slime can be drained easily.

Ice and fish should be placed alternately to avoid localized heating.
Fish must be sufficiently surrounded with ice on the sides, top and
bottom
When packing mixed fish, big fish must be placed at the bottom
and small fish on top. Fish with delicate skin should be packed on
top of fish with scales.

Gutted fish must be filled up with ice in the belly cavity and must be arranged with
belly down in a slanting position inside the container.
2. Chilled Seawater (CSW)or Jee Slurry:
This is also termed as "slush ice" which is a mixture of
seawater and crushed ice used for the chilling of fish catch.
The amount of ice depends on the initial temperature of the water and
the fish, the size of the container and the quality of its insulation, and
the length of the trip.

 The advantages of CSW over icing are:
1. CSW chills fish much faster than wet ice.
2. Fish in CSW do not suffer from physical damage
due to crushing or pressure from other fish.
3. Fish in CSW are washed in the slurry.
In spite of the advantages mentioned above, CSW chilled fish do not
necessarily keep longer than wet iced fish.
 Other Methods:
There are other ways of chilling fish such as:

Refrigerated Air:
Air chilling is commonly employed in big commercial
boats. Chilled air is circulated by a finned evaporator
and fan situated at one end of the fish room.
These units are often referred to as air blowers
 The cooling time generally exceeds 24 hours which is a reflection of the
slow heat transfer between the chilled air and the
stacked cases of fish.

3. Dry Ice
 Dry ice is solid carbon dioxide. Cooling is effected by the evaporation of the dry
ice.
 Due to its very low temperature (-78.9 °C), dry ice should not be used in direct
contact with fish to avoid cold bums.
This method of chilling is preferred for air shipment of fish as this
does not cause leakage.
However, the use of dry ice is subject to restrictions because it expands from
a solid form into a gas and it may expel oxygen, posing a hazard to the safety
of airplanes.

4. Gel Ice Mat
Gel ice is made by freezing a water-based gel.
The advantage of gel ice is that all water is bound with no chance
of water leakage during thawing.
Gel mat chilling is suitable for air transport of fish.
o Types of Ice
The water used for the manufacture of ice must be fit for drinking.
Depending on the temperature and length of storage, appreciable
numbers of bacteria can build up in the ice
Used ice will be heavily contaminated with spoilage bacteria and
must be discarded

 Spoilage of the fish will be more rapid when old or dirty ice is used.
The most common types of ice used in fisheries are the following:
1. Block Ice
• Block ice is made by freezing water in forms (cans or moulder) of the
desired size.
• The size of the block produced can vary depending on the
requirement
• Ice blocks are rarely used directly for cooling fish because of their
size and weight.
• They must be crushed into smaller pieces. Block ice melts slowly
but is easy to transport in insulated containers to the villages

 Crushed ice usually comes from blocks or slabs broken down through
mechanical crushers or manually.
3. Flake Ice or "Scale"

Flake ice is commonly produced from fresh water as thin flakes, formed instantly
on cold metallic surfaces such as the inside of a fixed, vertical cylinder.
The cylinder wall is kept below-20°C by constant refrigeration.
The ice formed is removed from cylinder by "sudden" heating and is collected
by a rotary scraper as firm and dry flakes.

The flakes fall directly into a storage bin, which is maintained about -6°C
Flake ice has the advantage of small particles which give good ice-fish
contact because of a large surface area.
The disadvantages of flake ice:
1. It is denser than crushed ice so more flake ice has to be used to
achieve the same cooling as crushed ice.
2. It tends to clump and it melts very rapidly making it less practical
for longer transport.

Tube ice is made by freezing water on the inside surface of a tube.
Tube ice lasts longer and melts more evenly than other shaped ice and is useful for
transporting fish in uninsulated containers.
The bulk density is midway between that of flake ice and crushed ice;
however, due to its cylindrical shape, it is not practical for icing.
It can also bruise the fish because of its relatively large size.
Methods of Storing Iced Fish:
1. Bulking
2. shelfing
3. boxing

Bulking
In bulking, the ice and the fish are layered to achieve intimate
contact, which will ensure the maximum storage life in ice.
This method of storing fish is usually utilized in the hold of
fishing boats to economize on space
Bulking has disadvantages when a very large volume of fish
needs to be stored

1. Fish can be physically damaged through the pressure of fish above and the
pressure of ice.
2. Bulked fish are in general of poorer quality than shelved or boxed fish after
the same storage time.
3. The unloading of the catch is difficult which could result to rough handling.

Shelfing
Shelfing is applicable to larger species, which are gutted. In this
method, the fish is stored in single layers, gut cavity down on a
bed of ice; sometimes a little ice spread on top.
This is designed to ensure bleeding through the cut
surface of the fish to retard spoilage by chilling

 Shelved fish, if well iced on top, are of better or
at least of equal quality to bulked fish. The fish
can be separated easily into different catches.

Boxing
Boxing is the preferred method of storing fish in ice. Fish and ice
are layered m specially made boxes.
The boxes can easily be moved for transport to market
or permanently fixed on board the fishing vessel.

 Several advantages of boxing:
1. The segregation of first-caught fish from last-caught fish, small from large, one·
species from another can be easily achieved.
2. Handling is kept to a minimum and, with a good boxing practice, fish will not
be damaged physically.
A disadvantage of boxing in some cases is that the space occupied in
storing fish is greater than that for bulking.

Types of Containers:
The choice of containers for keeping fish will greatly determine the end
quality of the iced product.
In the selection of a fish container, the following should be taken into
consideration:
1. insulating properties
2. proper shape and dimensions for the fishery product concerned
3. easy to handle, fill and empty
4. easy to clean and stack securely one on top of the other
5. constructed from non-poisonous materials
6. adequate provision for drainage of melt-water

 Plastic Box
 Plastic is the term used to describe a wide range of materials such as polyethylene
(PE) and polypropylene (PP).
Polyethylene box
polypropylene box

Plastics are composed of very large molecules (chains or lattices called
polymers).
 Polymers are made up of links or building blocks of distinct molecular structure called monomers.
High density polyethylene (HDPE) and polypropylene are widely used in
the manufacture of modern day containers.
 Polyethylene:
Polyethylene (PE) is made by subjecting gaseous ethylene
monomer to heat and pressure in the presence of a metallic
catalyst.
PE is classified into low density (0.910 to 0.925 g/cm3),
medium density (0.926 to 0.940 g/cm3) and high density

 High density polyethylene is divided into type Ill (density 0.94 l to 0.959 g/ cm3)
and type lV which has a density of 0.960 g/cm3 and above
In general, polyethylene has excellent toughness; it is resistant to chemicals,
oil and grease; inert to food; and has extremely low water vapor
transmission properties.
High density or rigid polyethylene (HDPE) containers have proven to be very
useful in the chilling of fish.
They are expensive but will last long. Furthermore, these containers can
withstand extreme heat or cold and are easy to clean because of their smooth
and non-absorbent surface.
They are usually built with proper drains. The container can very well retain
coldness inside.

 Polypropylene (PP):
Polypropylene is a homo-polymer of propylene. It has a low density (around
0.902 g/cm3) and superior processability.
lt is one of the lightest plastics, has a good resistance to grease and most
chemicals, provides a good barrier to water vapor and can withstand high
temperatures due to its high softening point.
Polypropylene is more rigid, stronger and lighter than polyethylene
Polystyrene (Styrophore)

 Polystyrene monomer is polymerized into high molecular weight poly• styrene through a free radical
mechanism.
Styrene chemically resembles ethylene, except it has a benzene ring attached.

 Polystyrene resin normally has a density of 1.0 to 1.1 g/cm3• Chemically, polystyrenes are
resistant to weak acids and bases, vegetable oils and others.
Polystyrene boxes are becoming popular locally for transporting fish from the
landing place to the market or fish plant.
However, the boxes are difficult to clean, do not last long and do not have
drainage for melt-water.
Further• more, they are difficult to move because they lack hand-grip.
The boxes must have additional wooden frames to make them durable and in
order to make handling of the containers easier.
The containers are difficult to clean especially if the pores are damaged. Dirt
is easily accumulated in the damaged pores

Galvanized Iron (GI) Sheet Tubs (Baftera)

Tubs made from GI sheets (baiiera) are conical in shape and so far the most
commonly used container by fishers in the Philippines.
These tubs are not provided with drains; they easily corrode they have poor
insulating property and are quite difficult to handle due to their fill capacity,
around 40-50 kg.
Baheras are becoming Jess popular locally and are slowly being replaced by
polystyrene boxes.
 Wooden Boxes:
 Wooden boxes can withstand rough handling and have relatively good
insulating property
 However, they are not easy to clean, and are slightly difficult to handle
because of their weight
 They become a hazard to handlers (splinters can cause injury) when they
are not properly maintained

Coconut, Bamboo or Rattan Baskets:

These baskets are cheap and easy to handle due to light material but difficult to clean
and do not last long.
Ice will easily melt in these baskets since they are loosely woven.
Pointers in Handling Chilled Fish
The choice of insulating material“ will depend on its thermal conductivity or
resistance and permeability to water vapor (waterproof), density and
compressive strength.

The following must be taken into consideration when handling
chilled fish:
1. Temperature
 Low temperatures (around 0°C) must be maintained until the
commodity reaches the consumer
 The fish must be chilled as soon as possible and kept chilled before
processing and during al I stages of fish preparation.
2. Time
 All delays must be kept to a minimum. The length of time the
fish can be kept in a chilling medium must also be known to the
fish handler.

3. Contamination.
 Care must be taken that no contamination occurs during chilling and
during the storage of chilled fish. Good hygiene and sanitation (good
housekeeping) must be observed at all times.
4. Damage.
 Physical damage such as bruises, cuts, punctures, etc.
must be avoided when handling chilled fish.

Title: SITE VISITATION /Laboratory Activity
Date: March 2-6, 2020
Time: 3:00 to 6:00 AM
Venue: Placer Fish Port, Placer Surigao del Norte
Participants: BAT second year students and BTLED-AFA Second year students
Responsible Person: ARMAN N. BERMON, LPT subject teacher/in-charge

Rationale:
The SSCT Mainit Campus offered Bachelor of Agricultural
Technology BAT and Bachelor of Technology in Livelihood Education Major
in Agri-Fishery Arts BTLEd-AFA, the said programs was in accordance to
the CHED approved curriculum which was focusing on the Agriculture and
Fishery, to address the agricultural sector of the Philippines, for further
learnings of the learners, the course designed to have an actual
observation to the local fish ports of the region, as one of the
requirements of the curriculum and to attain the vision and mission of the
institution.

Objectives:
1.To know the different types of ice use by the
fisherman of the Placer Fish port.
2.To know how to apply the proper storage using
different storage boxes and proper handling.
3.To know the methods of proper handling in fresh
fish.
4. To deal with the fishermen’s and middle men.

Date and
Time
Course
Section
Activity Persons involved
March 2, 2020
3:00 to 6:00 AM
BAT 2A 1. Assembly at SSCT-Mainit Campus
gate
2. Arrival at Placer Fish port
3. Courtesy call to the Placer Fish
Port Authorities
4. Interview and observation to the
fishermen’s and middle men’s
5. Ice plant observation
6. Departure
1. BAT 2A Students
2. Arman N. Bermon
3. Fish port authorities
4. Fishermen’s
5. Middlemen’s
6. Fish Vendor’s
Proposed Activity:

March 3, 2020
3:00 to 6:00
AM
BAT 2B 1. Assembly at SSCT-
Mainit Campus gate
2. Arrival at Placer Fish
port
3. Courtesy call to the
Placer Fish Port
Authorities
4. Interview and
observation to the
fishermen’s and middle
men’s
6. Departure
1. BAT 2B Students
2. Arman N. Bermon
4. Fishermen’s
5. Middlemen’s
6. Fish Vendor’s

March 4, 2020
3:00 to 6:00
AM
BAT 2C 1. Assembly at SSCT-
Mainit Campus gate
port
Placer Fish Port
Authorities
4. Interview and
observation to the
men’s
6. Departure
1. BAT 2C Students
2. Arman N. Bermon
4. Fishermen’s
5. Middlemen’s
Fish Vendor’s

March 5, 2020
3:00 to 6:00
AM
BAT 2D 1. Assembly at SSCT-
Mainit Campus gate
port
Placer Fish Port
Authorities
4. Interview and
observation to the
men’s
6. Departure
1. BAT 2D Students
2. Arman N. Bermon
4. Fishermen’s
5. Middlemen’s
6. Fish Vendor’s

March 6, 2020
3:00 to 6:00
AM
BTLED
AFA 2
1. Assembly at SSCT-
Mainit Campus gate
port
Placer Fish Port
Authorities
4. Interview and
observation to the
men’s
6. Departure
1. BTLED-AFA 2 Students
2. Arman N. Bermon
4. Fishermen’s
5. Middlemen’s
6. Fish Vendor’s

What to observed:
1.Chilling, refrigeration and freezing methods
2.Different types of ice
3.Methods of Storing Iced Fish
4.Types of Containers
5.Types of fish.

Chapter3 Chilling

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Chapter3 Chilling