Training Manual on Value Addition of Seafood

Packaging of Seafood Products

J. Bindu

Introduction Packaging of fresh fish

Packaging is crucial to our A suitable package for fresh fish

modern food distribution and marketing should keep the fish moist and prevent
systems. Without protective packaging, dehydration, retard chemical and
food spoilage and wastage would bacterial spoilage, provide a barrier
increase tremendously. The advent of against moisture and oxygen to reduce
modern packaging technologies and new fat oxidation and prevent permeation of
methods of packaging materials made external odours.
possible the era of convenience In India baskets made of split
products. In the past, the packaging bamboo, palmyrah leaf and similar plant
emphasized the expectations of the materials were traditionally used for
producers and distributors but has now packing fresh iced fish. However, they do
shifted towards the consumer since they not possess adequate mechanical
are becoming more demanding and strength and get deformed under
aware of the choices available stacking. The porous surface of these
(Piergiovanni, 1991). A food package containers tends to absorb water and
usually provides a number of functions accumulate slime, creating an ideal
in addition to protection. breeding ground for spoilage bacteria,
Fish is one of the most perishable which can contaminate the fish. Even
of all foods. The best package cannot though washing cleans the
improve the quality of the contents and contaminated surfaces of the container
so the fish must be of high quality prior it will be ineffective in reducing the
to packaging (Fujita, 1990). Different bacterial load significantly. Sharp edges
products have different packaging of bamboo also cause bruises on the
requirements and it is important to skin of fish. Used tea chests provided
choose suitable packaging material with 2.5 cm thick foamed polystyrene (in
accordingly. It is important to know the polyethylene sleeving) slabs inside have
intended storage conditions of the been found extremely beneficial for
product, i.e., temperature, relative transport of fish over long distances up
humidity and expected shelf life. This is to 60 hours duration. Modern insulated
why multilayered plastics are very containers are made of HDPE or
popular since properties of different polypropylene with polyurethane
films can be effectively used (Mueller, insulation sandwiched between the
1991). The basic function of food inner and outer walls of the double
packaging is to protect the product from walled containers. They are durable and
physical damage and contaminants, to in normal use have a life span of over 5
delay microbial spoilage, to allow greater years. Materials such as aluminum,
handling and to improve presentation. steel and fibreglass are also used in the
construction of insulated containers.
Insulation properties of these containers

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depend on the integrity of the layer of aquatic products exported from India to
insulation. Contamination of insulation the European, USA, Japan and Middle
layer with water drastically reduces East countries is frozen in different
insulation properties of the medium. A forms and packs. These products are
recent development is an insulated processed and packed for export to the
corrugated plastic container, which is European, USA, Japan and Middle East
the lightest of all packages available in countries. Fish being highly perishable
the country for iced fish transport. It transportation and storage of frozen
lasts for 5 trips with collapsible design fishery products requires a cold chain.
and lightweight, return of empty Hence, these fishery products are stored
container is very easy. For cycle at temperatures below –18° C. They are
hawkers U shaped box (100 kg capacity) transported by sea in refrigerated freight
made of high molecular weight high containers of the reefer type. The kind of
density polyethylene is found ideal. An packaging and the material used
insulated galvanized iron box (40 kg depends on the value of the product and
capacity) was introduced for the end user or customer. Both
multipurpose use on boats and consumer and bulk packaging are used
processing centers. They did not to facilitate trade. The retail pack of
become popular with the trade because smaller quantity is used for household
of high tare weight (27 kg) and corrosion purposes whereas bulk packs with
of metal parts in sea atmosphere. Some larger quantities are used in
of the workers experimented the use of restaurants, catering services or for
fibreboard containers for the repacking into consumer packs.
transportation of iced marine and fresh The main items of export of frozen
water fish and frozen fish. They found products are block-frozen shrimps,
that fish could be transported in good cephalopods and fishes. IQF and value
condition for 60 hours covering a added fish products form only a minor
distance of 1700 km in fibreboard portion of the trade. Market research
container and wood wool used in has indicated that there is need for
between two walls of containers was standardization of current materials,
found to provide effective insulation. styles and modes of packaging of frozen
Wooden boxes and used plywood boxes foods. At the same time, it is necessary
of 20–120 kg capacity is used in western to give attention to cost –effective
parts of the country for transport of fish packaging material.
by rail and road. Generally, these boxes Fishery products are frozen at –
are again used for transport of fish at the 40°C. However cold storage temperature
receiving point to other places. The where they are subsequently stored
boxes lose their insulation property on varies from -30 to –18° C. The enzymatic
becoming wet and tend to become heavy. activities bring about deteriorative
changes like rancidity in frozen fish
Packaging of frozen fish products. Exposure to low temperatures
for a long time may result in freezer
World trade in frozen fishery burns. Hence for extending shelf life and
products has been increasing every year. further storage, packaging is of absolute
In India, frozen fishery products form a importance. To get a quality frozen
major constituent of the export product in perfect condition the package
earnings. About 80 percent of the total must provide protection against

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dehydration, oxidation, flavour and effective in providing increased

odour loss and physical changes. insulation. Laminated packs are usually
Evaporation of moisture from the used for IQF products. The sequence of
surface of the fish may occur resulting packing starts with the primary inner
in freezer burns. In order to overcome wrap and finishes at the master carton.
these problems suitable packaging is
absolutely necessary. Packaging for block frozen
The advantages of packaging products
frozen fish are
• Prevention of dehydration a. Primary wrap for block frozen
• Prevention of rancidity in fatty products
fishes
• Protection against contamination The material used as a primary
and physical damages wrap for contact with the food is mainly
• Convenience of handling the Low-density polyethylene (LDPE). This
product can be in the shape of a bag or a film.
• Retention of flavour and colour Usually 2 kgs or 5 pounds material is
• Attractive appearance of the packed along with 10-20 % glaze.
product Glazing should be optimum at the
• Prevents leaching while thawing recommended level, since this will add to
• Convenience in handling and packaging and transportation.
using a portion of the product. Alternately, films of HM-HDPE, which is
not as transparent as LDPE film can be
used, being more cost effective. 100
Packaging for various frozen fish gauge LDPE is used for wrap while 200
products gauge is used for bag. The corresponding
values for HDPE are 60 and 120 gauge.
The packaging used for frozen Polyethylene films should be of food
fish products should be of good quality. grade conforming to IS: 9845
It should protect the product from specifications, which are given below in
transit and storage hazards as well as Table 1.
provide a barrier for retention of
moisture. Packaging material used for b. Duplex carton/ Inner carton
frozen fresh fish is mainly polyethylene,
either as premade bags or wraps which There are four types of cartons
are then packed into waxed duplex used for packaging of seafood products,
cartons. Frozen fish are also over which are top opening, end opening, end
wrapped in polystyrene trays for display. loading and tray type. In top opening
Individual fillets are packed in carton system filling is done from the
cellophane or PVC. Vacuum packaging top. This is mainly for filling larger
of fish fillets and steaks in laminate pieces of fish and cephalopods. End
films, and PVDC copolymer system is opening type cartons are used when the
also practiced. The corrugated product is smaller and free flowing, like
fiberboards are usually waxed or packaging of fish curry or soup. Here the
provided with a liner. Sometimes an carton is coated with polyethylene on
inner slab of polystyrene foam is both inside and outside. The end loading

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system feeds the product from one end Table 2. Specifications for duplex
into a horizontal glued carton. End flaps cartons
are heat sealed or closed by tucks in
flap. End loading is suitable for products
Material Duplex board
packed in aluminum /carton trays. Tray
type cartons consist of cartons systems/ Style of carton preferably one-piece
polypropylene trays, which are sealed staple fewer cartons
with a lid and used for production of Grammage 300g/m2 (minimum)
frozen pre cooked food that will be
Bursting 4 kg/cm2
heated and thawed in the package itself.
strength (minimum)
To withstand heating, the board is
coated with polypropylene. Wax coating inner& outer side.
The frozen blocks are wrapped in 10g/m2 on each side
film and then packed in duplex cartons. (minimum)
A number of such blocks are packed in Polyethylene 20 gsm on each side
a master poly bag and then packed into coating
master cartons. The carton should have
Ring stiffness 270 N
details like net weight, type and size,
name and address of the producer and Printing details Brand name,
the country of origin. Specifications for product type, net
duplex cartons are given in Table 2. content, size grade.
Identification of
packer, country of
Table 1: Specifications for primary
origin.
wrap for block frozen products

18 gm/ sqm / 90  Source: Fish Packaging Technology –

Water vapour Materials and Methods, Concept
2 % RH / 24 hrs /
transmission rate Publishing Company
37 ° C
Not less than
120kg/cm2 in c. Master carton
Tensile Strength machine direction
85 kg/cm2 in cross
direction In the case of frozen shrimps
100 per cent in about 6 units of 2 kg each or 10 units of
machine direction 2 kg each are packed into master
Elongation at break
350 per cent in cartons. Corrugated fiberboards are
cross direction used for the packaging of frozen fish.
They may be of virgin material and
Overall migration
residue
60 mg/ litre or 10 having three or five ply with liners. The
mg/dm2 cartons may be wax coated or supported
with liner paper with higher wet strength
to make it moisture resistant. The
specifications (Table 3) for master carton
vary depending upon the country or the
type of pack.

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Table 3: Specifications for master d. Strapping and tying

carton (10 units’ carton)
Boxes are now mainly closed at
Material Corrugated the top and bottom by using cellophane
fibreboard tapes. They are also stapled or strapped
by using polypropylene / high density/
Style of box Constructed from
rayon extruded straps. The straps are
one piece of board
clipped or heat-sealed. The tensile
Number of 3 or 5 ply corrugated strength must be great enough to
plies paper board withstand the load. In the case of
Type of flute B or C and polypropylene, the fluctuations in the
combination of these tensile strength and elongation at break
(%) at –20°C are comparatively less.
Position of flute Vertical Hence this material is most suitable
Bursting 14 kg/cm2 min when compared to HDPE where the
strength tensile strength and elongation at break
Puncture 160 oz in. / tear in vary. The specifications are given in
resistance Table 4.
Cobb value 120 g/m2 max
(30min) Table 4: Specification for straps
Compression 350 (minimum)
strength (kg) Closure Minimum of 2
straps to be
Manufactures Staples on the
tensioned and
joint outside. Overlap not
heat sealed
less than 3 cm.
Staples not more Type of strap Polypropylene
than 6 cm apart and (pp)
not further than 2.5 Width of strap 12 mm
cm from beginning
Tensile strength 1,500 kg/cm2
and end of joint
Elongation 20 % minimum
Type of glue Water resistant,
preferable starch Breaking load 75 (minimum)
based or any other Source: Fish Packaging Technology –
neutral adhesive. Materials and Methods, Concept
Wax coating Inside and outside of Publishing Company
20 g/m2 (min) on
each side. e. Packing slip (Code slip)
Printing details Product details,
country and Two packing slips are usually
packer/exporter used. One placed on each side of the
details. block. The slips should record the type,
Source: Fish Packaging Technology – quantity, batch number, producer code
Materials and Methods, Concept and packing details.
Publishing Company

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f. Printing packs ranging from 100g to 5 kg. An IQF

pack has a single glaze on its surface
• The printing should be in one and because of the larger surface area,
colour. The exterior of the master they are vulnerable to several risk.
carton should have the following Essential characteristics required for
information printed. packaging materials of IQF shrimps are
• Name of the Processor and • Low water vapour transmission
exporter rate to reduce the risk of
• Country of origin and destination dehydration
• Gross and net weight • Low gas/oxygen permeability,
• Type of packing thereby reducing the risk of
• Name of the product and code of oxidation and changes in colour,
packing flavour and odour
• Name and address of the • Flexibility to fix the contours of the
consignee food
• Transit instructions (perishable, • Resistance to puncture,
hold at –20°C) brittleness and deterioration at
low temp.
• Ease of filling
g. Storage and ware housing
IQF shrimps are filled in primary
The use of wooden pallets and containers along with code slip and
racks to store the filled boxes is weighed. Bar coding is nowadays
recomended throughout in- factory adopted which will depict various
handling and storage to ensure that product and inventory details through a
damage is avoided before the boxes leave series of bars. Bar coding is compulsory
the plant. for products imported to the EEC and
US markets. The product is filled into
h. Containerization primary pack which is heat sealed and
further packed in master cartons for
It is essential that the optimum storage and transportation. The primary
use be made of the freight container. pack may be plastic film pouches
This means that boxes of suitable (monofilm co-extruded film or laminated
dimensions that fit closely in the pouches). The unit pouches may be
container should be made. A large provided with unit/intermediate cartons
variety of sizes and dimensions of or directly packed into master cartons.
shrimp packaging has been used in The unit/intermediate cartons are made
India. of duplex or three ply corrugated
fibreboard laminated with plastic film on
the inside and outside to improve the
Packaging of Individually Quick functional properties as well as aesthetic
Frozen (IQF) Products value of the pack. The most functional
cost effective film has been identified as
Packaging requirements of IQF 10 biaxially oriented polypropylene
shrimps are different from block frozen (BOPP). Some duplex cartons are also
products. IQF shrimps are mainly wax-coated. One major requirement of
packed for retail marketing in consumer the master carton is high compression

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strength to bear weight without damage flavour changes due to the oxidation of
to the product. Compression strength of the product and also migration of flavour
500 kg is the minimum recommended from the packaging material. As fish
specification, which might give contains fat there will be chances of
reasonable safety to the product. The taking up the taints from the packaging
cartons made of 5 or 7 ply corrugated material. The particular structural
fibreboard satisfying the above properties of freeze-dried products lead
requirement can be safely used. to damage by mechanical means. The
light porous nature causes them to be
Packaging of battered and breaded very fragile and easily prone to breakage
during handling and transportation.
fish products
Freeze dried products are also liable to
damage caused by free movement within
These are value added products the package. Measures must be taken to
in convenience form. A number of value fit the product compactly in the
added marine products for export and container, while leaving the minimum
also for internal markets are prepared headspace for filling inert gas.
from shrimps, cephalopods, fish and
minced fish. Battering and breading
Rigid containers both glass and
process increases the bulk thus
cans were used earlier for packaging of
reducing the cost element.
freeze dried products. However, it can
now be seen that metalized polyester
Thermoform trays produced from laminated with polyethylene or
food grade materials like PVC, HDPE are aluminum foil /paper/polyethylene are
suitable for packaging of fishery used since they have low oxygen
products. These trays are unaffected by transmission rate and water vapour
low temperature of frozen storage and transmission rate. Most of the packages
provide protection to the contents are filled with an inert gas. The product
against desiccation, discoloration and can also be packed under vacuum to
oxidation during prolonged storage. give better protection against damage.

Packaging of Accelerated Freeze Packaging of Surimi

dried products
Accelerated freeze dried products Surimi is a Japanese term for
demand a very high price in the export mechanically deboned fish mince from
trade. The final moisture content of AFD white-fleshed fish that has been washed,
products generally is about 2 %. Low refined and mixed with cryoprotectants
moisture content and large surface area for good frozen shelf life. Surimi is used
make these foods extremely hygroscopic. as an intermediate product / raw
Most dried products deteriorate when material for processing several value
exposed to oxygen. Changes in colour added products like fabricated foods,
also may take place as a result of shrimp and crab analogues and a variety
bleaching. Light accelerates oxidative of other products. Surimi requires to be
reactions and hence contact with light preserved frozen until used for
should be prevented. If proper packaging processing different products. For this
materials are not used there is every purpose, surimi is generally frozen as
chance that the materials may undergo

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rectangular blocks. In order to prevent Packaging of Fish Pickle

probable deterioration during storage
like oxidative rancidity and desiccation Fish pickle is a value added item
care has to be taken to ensure that the whose bulk is contributed by low value
frozen block does not contain any voids items like ginger, chilly, acetic acid etc.
and that the packaging materials used Generally low cost fish and shell fish
have low water vapour permeability and components are used in fish pickles.
low permeability to gases and odours. Conventionally glass bottles are used as
The packaging materials employed containers, which offer properties like
should be sufficiently strong and inertness, non-toxicity, durability, non-
durable to withstand stress during permeability to gases, moisture etc. But
handling, storage and distribution. they are heavy, prone to break,
Packaging employed for block frozen voluminous and expensive. New flexible
shrimp are considered safe for surimi. packaging materials developed for fish
pickle is based on plain polyester
Packaging of Fish Sausage laminated with LDPE-HDPE co-extruded
film or Nylon/Surlyn or
Fish sausage is a product LD/BA/Nylon/BA/Primacore. These
identical to the popular pork sausage. are inert to the product, can be
Surimi is the base material, which is attractively fabricated as stand up packs
homogenized after mixing with several and can be printed on the reverse side of
other ingredients. The homogenized the polyester film.
mass is stuffed in synthetic casings like
Ryphan (Rubber hydrochloride) or Packaging of Fish soup powder
Krehalon (Vinylidene chloride) or
polyamide. Other casing available are Fish soup powder is a specialty
cellulose casing which are permeable product containing partially hydrolysed
and can help in the penetration of smoke fish, protein, carbohydrates, fat and
during the process. The casing is closed several other seasonings including salt.
using metal rings after which it is heated The product is hygroscopic and hence
in water at 85-90°C and then slowly the selection of the package assumes
cooled. After drying the surface, the great significance. Appropriate package
sausage is wrapped in cellophane developed for such products are
laminated with polyethylene. Fish 12micron plain polyester laminated with
sausage is kept at refrigerator LDPE-HDPE co-extruded film or 90-100
temperatures for retail; however, when micron LD/BA/Nylon/BA/Primacore
prolonged storage is needed it is better multilayer film which ensure a safe
kept frozen. Duplex cartons lined with a storage of the product up to 180 days
plastic film are ideal for short-term
storage, but when stored frozen,
packaging suggested for block frozen Packaging of Dry Fish Pickle
shrimp can be considered suitable.
Fish pickles generally have high
content of liquid gravy and hence
present some problems in its packaging.
Dry fish pickle with no gravy will be more
suitable for packaging, transportation

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and distribution. Many small varieties have been found quite acceptable to the
of fishes are generally dried and consumers. A packaging material which
marketed; however, these fishes offer a offers safe storage of the product up to
very good raw material for processing 14 months at ambient temperature has
into dry pickle which is considered a been identified as nylon/surlyn or
value added product. Such products LD/BA/nylon/BA/prim core.

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