Rupesh N. Chavan
B.Tech 3rd Year,
Under the guidance of
Mr. G. M. Hend.
Convenience food is a concept that is
prevalent in the developed world since
long, while its inception into the Indian
market has been recent. With the changing
socio-economic pattern of life and the
increasing number of working couples, the
concept is fast becoming popular in Indian
market. This type of food is becoming
popular because it saves time and labor.
This food has extended shelf-life and is
available off the market shelves.
Packaged/convenience food products
sector has been slow in penetrating the
large potential presented by Indian 250
million strong middle class. But due to
growing urbanization and changing food
habits, the demand has been rising at a
good pace and there is enough latent
market potential waiting to be exploited
through developmental efforts.
Thermal sterilization of low-acid food products (LACF), sometimes referred to as
retorting, has been a widely accepted means of food preservation for many
Retort pouch which is a flexible pack. Material has been developed as an
alternative to metal can and glass bottles. It is flexible laminated pouch which can
withstand thermal processing temperature of 120-130°C and combine advantage
of metal can and plastic boil- in-bag. It provides superior barrio properties for a
long shelf life, toughness and punctuating resistance. Such pouches are normally
used for packaging low acid products like meat, fish, veg., rice products.
The retort pouch is a rectangular, flexible, laminated plastic, four side
hermetically sealed pouch in which food is thermally processed. It is a
lightweight, high-quality, durable, convenient and shelf-stable packs.
The material from which retort pouches are made are either aluminum foil
bearing/plastic laminates or foil free plastic laminates films. These must be inert,
heat sealable, dimensionally stable and heat resistant to at least 121°C for
typical process time. They should have low oxygen and water vapor permeability.
They should physically strong,
Selection of packaging
The advancements in food technology and
packaging technology have made it
possible to extend the shelf-life of various
food products. Before deciding which
packaging material is to be used, it is
necessary to know the packaging
requirements of the product i.e. what
hazards will cause product deterioration
and the conditions to which the packaged
product will be subjected throughout its
Factors which influence the selection
criteria for choosing packaging materials,
• Product Characteristics • The type of food and its composition,
moisture, fat, protein, flavour etc.
• Form and shape of the product – smooth, regular, irregular, with
sharp edges etc.
• Nature of the product – crisp, brittle, sticky etc.
• Factors Affecting Packaging Factors responsible for the spoilage
of the food products:
• Biological spoilage due to micro-organisms
• A biotic spoilage due to chemical reactions like oxidation,
hydrolysis and enzymatic reactions.
• The environmental factors like light, humidity and temperature.
• The food processing parameters e.g.. processing temperature
• The shelf-life desired for a given ready-to-eat food, influences the
type of packaging and processing parameters to be used.
Definition of Retort packaging
Retort packaging materials are defined by
ASTM (American Society of Testing and
Materials.) as “Those packaging
material which is capable of
withstanding specified thermal
processing in a closed retort at
temperature over 100°C.”
Role of thermal processing:-
Food is spoiled principally by the action
of micro-organisms. Thermal processing
destroys these harmful micro-organisms
by heat. The aim of thermal processing
is to bring the food as rapidly as
possible to a temperature at which
unwanted organisms are killed, and to
hold the food at that temperature long
enough to render the food “commercially
The convenience food could be
basically classified into two
Shelf – stable convenience food
Frozen convenience food
Shelf-stable convenience food are further
• Ready-to-Eat (RTE) and Ready-To-Serve (RTS)
food - e.g. Idlis, dosas, pav bhaji, meat products like
pre-cooked sausages, ham, chicken products,
curries, chapattis, rice, vegetables like aloo chole,
navratan kurma, channa masala etc.
• Ready-to-Cook food – e.g. instant mixes like cake
mixes, gulab-jamun mix, falooda mix, icecream mix,
jelly mix, pudding mix etc., pasta products like
noodles, macaroni, vermicelli etc.
Packaging Requirements of Ready-to-Eat
(RTE) and Ready-to-Serve
A “ready-to-eat” food product may be defined as any
food product which does not require any elaborate
processing procedures on the part of consumer
before it is good enough for consumption. It is ready-
to-eat as soon as the pack is opened in a form,
which is tasty and appetizing.
The advancements in food technology and
packaging technology have made it possible to
extend the shelf-life of these products. Before
deciding which packaging material is to be used, it is
necessary to know the packaging requirements of
the product i.e. what hazard will cause product
deterioration and the conditions to which the
packaged product will be subjected throughout its
WHY READY TO EAT FOODs:-
„ Globalization of Indian food and its culture are the
core factors for popularization of ready to eat foods.
„ Main motivation for these ready to eat foods is fast
growing foreign market. „
Retail outlet culture is now growing rapidly in India. „
Shelf life of these foods are at least 12-18 months. „
Quality, Taste and Flavour of these foods remains as
good as fresh up to the expiry date.
Women wanting to spend more time out of the
More working bachelors staying away from homes.
„ Cost effective in comparison to the Indian cuisine
served by the restaurants in foreign countries.
History of Retort Pouch
In the late 1940’s, the initial concept of a flexible package for
sterile food products was developed. The United States military
was the first major consumer of retort pouches in the form of
meals-ready-to-eat (MRE) as a replacement for C-rations which
were packaged in a rigid metal cans. FDA and USDA recognize
qualified individuals trained in thermal processing techniques as
process authorities. Process authorities specify the time,
temperature and other factors required to render a food product
in a retort pouch commercially sterile. Retort pouch products
have a distinct advantage over similar volume products
packaged in rigid metal cans or glass jar in that it has quicker
heat penetration. Faster product heating allows for improved
quality of the food product. Other advantages that retort
pouches have compared to rigid containers is their lighter
weight and easier opening. Retorting food products in flexible
pouches has several key differences when compared to rigid
metal cans. The pouch materials, styles, filling, sealing and
Operation in which product is
placed in a hermetic container (canned
foods or retort pouches), heated at a
sufficiently high temperature for a
sufficient length of time to destroy all
microbial and enzyme activity (Note -
"commercial sterility" implies less than
absolute destruction of all micro-
organisms and spores, but any
remaining would be incapable of growth
in the food under existing conditions).
What is Retort Pouch
A retort pouch is constructed from a flexible
metal-plastic laminate which is able to withstand
thermal processing used for sterilization. The food is
first prepared, even raw or semi cooked, and then
sealed into the retort pouch. The pouch is then
heated to 240-250°F (116-121°C) for several minutes
under high pressure, inside retort or autoclave
machines. The food inside is cooked, similar to
pressure cooking. This process reliably kills all
commonly occurring microorganisms (particularly
Clostridium botulinum), preventing it from spoiling.
The packaging process is very similar to canning,
except that the package itself is flexible. The
lamination structure doesn't allow permeation of
gases from outside into the pouch.
Retort pouch is a special package in which the
perishable food items are preserved by physical, and/or
chemical means. It is a flexible laminate, which can
withstand thermal processing, and combines the
advantages of the metal can and the boil-in- bag.
Ready-to-use retort pouches are flexible packages
made from multilayer plastic films with or without
aluminium foil as one of the layers. Unlike the usual
flexible packages, they are made of heat resistant
plastics, thus making them suitable for processing in retort
at a temperature of around 121°C. These retort pouches
posses toughness and puncture resistance normally
required for any flexible packaging. It can also withstand
the rigours of handling and distribution. The material is
heat sealable and has good barrier properties.
Retort Pouch Material
The material used depends upon the
barrier properties required, the process
temperature which will apply and
Construction of Retort
A retort pouch is constructed from a flexible metal-
plastic laminate which is able to withstand thermal
processing used for sterilization. The food is first
prepared, even raw or semi cooked, and then sealed into
the retort pouch. The pouch is then heated to 240-250°F
(116-121°C) for several minutes under high pressure,
inside retort or autoclave machines. The food inside is
cooked, similar to pressure cooking. This process reliably
kills all commonly occurring microorganisms (particularly
Clostridium botulinum), preventing it from spoiling. The
packaging process is very similar to canning, except that
the package itself is flexible. The lamination structure
doesn't allow permeation of gases from outside into the
pouch. The particular retort pouches used for several
products consist of four layers bonded in a lamination
In fabrication a web of laminate is drawn from roll-
stock through a plow assembly which folds the web in
creating the front and rear walls of the pouch. Two
opposing hot bars then apply the bottom seal and two
opposing cooling bars stabilize it. Two adjacent side seals
are then applied by double width hot bars and stabilization
is achieved at the next section. Corner rounding and tear
notch formation are performed by pouch and die
assemblies after the side seals are formed. At this point,
the pouches are separated with cut off knife and their
progression from here is dependant upon whether they
are fabricated on a FFS unit or are manufactured on an
independent operation for use with pouch fill-seal
The pouches commonly used in the local industries
are the preformed type. i.e. With 3 sides already sealed.
Thermal process and retort
For satisfactory processing of retort pouches, it is
necessary to use the “OVER PRESSURE” type retort in
order to maintain pouch integrity during heating and
There are main 3 categories of over pressure retort
system used for pouch processing are:-
1) Full water immersion batch retorts:- This is the oldest
technology and most common.
2) Water trickle, spray or cascade batch retorts:- This
retorts use minimal water for heating medium application
in conjunction with air over pressure.
3) Steam/ air batch retorts:- These retorts use a mixture of
steam and air as the heating medium. The air is source
of the over pressure. This retort provide a more gentle
ramp and less thermal shock to the product and offer
shorter come up time.
One Frenchy system, the “steritech” retort is used in
Thailand for pouched Thai food products. Another
Japanese steam-air retort is used for tuna in pouches.
The rack system used to hold the pouch during
retorting is as important as the retort itself. The rack
system must be designed to allow adequate heating
medium circulation around each container to contraining
thickness and side to side movement. The rack must
prevent container to container contact. Whatever the
heating medium both the heat distribution and heat
penetration are critically important for each product and
container size. For this reason racking configuration is
important in container processing and should be designed
for the specific container and retort system.
Functions of Layer
Aluminum-foil:- it provides good barrier properties against
oxygen, light, moisture, vapor and extend shelf life. Those
without aluminum foil are transparent.
The outer polyester film provides strength and toughness are
stable for high temperature.
While the inner polypropylene provides good heat sealing
properties, strength, flexibility and compatibility with all
The additional incorporation of an oriented PA (nylon) film layer
further increases the durability of the pouch, especially where
the individual pouches are not, subsequently, packed
individually in cartons.
The layers are laminated to each other using specially
developed thermo-stable, food compatible adhesives.
Typical thickness: PP-0.00039”, 0.00035” Al foil, 0.00059” Nylon,
Requirements of Retort Films:-
Low oxygen permeability-
Sterilization temp. stability-0 to 150°C
Low water vapor transmission rate-
Heat sealability-160 to 260°C
Thickness tolerance- ±2 micrometer
Seal strength-2 to 3.5 kg/10mm
Busting strength- 7.5kg/cm²
Process Packaging Store Transport Store Deploy
1)Preformed Retort Pouch:
Automatic or Manual Transport
Packing and retort loading
Filling of Product
Pouch OpeningPre-Formed Retort Pouch
2)Form-Fill-Seal Retort Pouch Processing
Retort Film Web (Reel)
Forming Into Pouch
Automatic or Manual filling of Product
Heat Processing and Cooling
Steam Cooker or Seam Air Mixer
Weigh and Filling Into
Production of Pouches
Pouches can either be formed from reels
of laminated material either on in-line
form/fill/seal machines in the packer’s
plant or they may be obtained as
preformed individual pouches sealed on
three sides, cut and notched.
Filling and Sealing:-
In-lined and preformed pouches are filled vertically. Vertical
form/fill/seal machine can be used for liquid products.
Another method employs a web of pouch material which is
formed on a horizontal bed into several adjacent cavities. The
cavities are filled whilst the sealed areas are shielded. This
method is specially useful for filling space able products.
Thereafter the filled cavities are simultaneously sealed from the
top using a second web fed from the reel.
Pouch closure is normally accomplished by some means of air
removal, either by steam flushing or by drawing a vacuum in a
sealed chamber or simply, in the case of liquid food products,
flattening the pouch by squeezing between two vertical plates.
Efficient air removal prevents ballooning and rupturing during
retorting. Never hot pack in retort pouches. The bag could burst
causing burns or other problems. All products must be cooled
completely before vacuum sealing. Then remain in a cold
environment until placed directly into the pressure canner for
Processing takes place in steam heated pressure
vessel or retorts. The system provided by
either of the following:
1) Steam heated water with compressed air
2) Mixtures of steam and air
Instrumentation and control valve systems are
vitally important to accurately control ant
record pressure and temperature (+1°C to -
0.5°C) during the retorting of pouches. In
automatic process cycle, control is preferred.
Vertical retorts may be used but horizontal
batch retorts are the most commonly used.
Post Retort Handling
Following pressure cooling and removal
in racks or trays from the retort, the
pouches must be dried, inspected and
placed in some form of outer packaging.
When dry, pouch seal may once again
visually checked or inspected for leaks,
ruptures or weak points that have been
shown up during retorting. This should
not involve manual handling of the
The secondary packaging of retort
pouches for storage and distribution
may either involve packing each pouch
in printed carton or, alternatively packing
a number of pouches in a transit case,
possibly incorporating vertical dividers.
Still Retort with Overpressure
*Pressure in excess of normal pressure
at a given temperature
*May now have air introduced to retort
during processing as well as cooling
*Maintain container integrity
*Internal pressure developed during
processing is greater than pure steam
Still and agitating retorts may be batch or
continuous. Continuous retorts have four
These retorts have self sealing valves
which maintain pressure and tolerate
temperatures up to 143°C.
Some retorts agitate the cans during processing
in order to increase the rate of heat penetration
into the cans. Agitation may either be axial or
end over end. Agitation is useful for products
which are too viscous to heat or cool by natural
convection. By using agitation, the process time
may be reduced by up to 80%. Mixing is largely
due to the movement of the headspace during
agitation and to be effective there must be a
sufficiently large headspace inside the can. A
small headspace may lead to under processing.
Quality control program for
Q.C. Procedures must include not only the end item or
final product testing based on samples, but also audit
procedures to verify that production procedures adhered
Incoming pouch should be visually inspected for any
defects and checked for quality and strength of the seal
upon receipt every incoming lot.
During process it is important to control fill weight and
pack thickness; evacuation sealing (avoidance of
contaminants and proper time/temp.); the thermal process
parameters; and post process container handling to
minimize damage. In order to achieve an absolutely
minimum reject level of defective pouches especially for
leaks, retort pouches must be 100% inspected in process
after sealing and after retorting.
Indian Retort Foods
Indian food like palak paneer, dal fry, curry
rice, upma, vegetables biryani etc. are
retort processed hence their packaging
requirements are different. These products
are retort processed because they are low
acid food with moderate to large size
particles; hence it is easy to remove
oxygen from the head-space by gas
flushing. The selection of a polymer or its
combination is based on the requirement of
PLAYERS IN READY TO EAT
Advantages and Disadvantages
of Retort Pouches:-
less energy is required to manufacture pouches compared with cans
• transport of empty containers is cheaper (85% less space required than
• packaging is cheaper than equivalent can and with carton cost is about
• filling lines are easily changed to a different size
• rapid heat penetration and faster process results in better nutrition/
• contents are ambient shelf stable – no refrigeration is required
• packed pouch is more compact requiring about 10% less shelf space
• less brine or syrup used, pouches are lower in mass and cheaper to
• fast reheating of contents by immersion of pack in hot water. No pots to
• opens easily by tearing or cutting
• ideal for single portion packaging and serving size control
• retort pouch materials are non-corrosive
• convenient for outdoor leisure and military rations use.
filing of crates and loading into crates is much slower
and much complex than can or glass containers.
Establishing the scheduled process and controlling
critical factors is more complex.
Pouches are more sensitive to snagging and cutting
impacts, as well as to a softening effect during
heating; therefore a pack integrity can be more easily
compromised than in rigid containers.
High capital investment , especially in equipment
necessary for appropriate pouch handling during
loading and unloading of the retort (e.g., stackable
trays ,rack) and during post thermal process
handling to ensure pack integrity.
From Processor’s Point of
Shorter sterilization cycle due to thin profile
of containers. Hence, there is 30% -
40%reduction in processing time compared
Less deterioration of flavor, taste, color and
nutrition-due to reduced exposure to heat.
Empty containers save almost 85% of
space during warehousing when compared
with empty cans.
Being light in weight, transportation
charges are less
From Consumers Point of
Easy to handle
Easy to cook
Easy to open
What's going in India:-
In India, 3-ply laminate consisting of PET/Al
Foil/PP is commonly used for packaging of
ready to eat retort packed food. The product
packed in such laminates has a shelf-life of
one year. The other materials generally used
in retort pouch structure includes nylon, silica
coated nylon, ethylene vinyl alcohol (EVOH)
and polyvinyledene chloride (PVDC). These
materials have high moisture barrier properties
and are used successfully for packaging of
ready-to-eat high moisture Indian food.
Both preformed pouches as well as
pouches formed on FFS machines are
used. Preformed pouches are of flat and
stand - up type. The typical structure of
these pouches are:
Flat configuration : 12µ PET/12µ Al foil/
Stand up configuration : 12µ PET/9µ Al
foil/ 15µ OPA/60µ PP
MARKET & ITS GROWTH
„ 1)The popularity of ready to eat packed food now is no longer
marks a special occasion. Peoples want value for time, money
in terms of quality and variety. „
2)The food processing industry is one of the largest industries in
India and it is the ranked fifth in terms of Production,
Consumption, Export & Expected growth.
„ 3)Processed food market in India accounts for 32% that is Rs.
1280 billion or 29.4 billion US $ in a total estimated market of
Rs. 3990 billion or 91.66 US $.
4) Euromonitor International, a market research company says
that amount of money Indian spend on ready to eat snacks &
food is 5 billion US $ in a year while on abroad Indian or Indian
subcontinents spend 30 billion US $ in a year.
„ 5)Ready to eat packaged food industry is over Rs. 4000 crore
or 1 billion US $ and it is growing at the rate of 20 % per
annum. „ Ready to eat food market is developing specifically in
UK, USA, Canada, Gulf & South Asian Countries with the
growth rate of over 150 % per annum.
A few exporters of retort pouch
foods in India are –
1. Shri Venue exports – Mumbai,
2. Britto Exports – Chennai,
3.Gujarat State Export Corporation –
4.Tasty Bite Eatables, MTR Foods, ITC Foods,
5. Satnam Overseas – New Delhi, ADF Foods
Tasty bite has US factory production
capacity of 100000 meals per day, while the
Indian outlet has around 50000 meals per day
1)What is retort packaging?
– Retort packaging is a self stable flexible package
What is the shelf life of retort food?
– The shelf life of a retort package is a year plus.
What are the shipping advantages? – A retort package will not
break or dent and weigh less.
Where do you display the package in the retail store?
– You can display at room temperature at any corner of the retail
What are some of the main reasons, a packager of consumer
products would like to go from a conventional package material
to a flexible retort pouch?
– The package provides a flat surface for graphics and text, needs
no refrigeration and is microwave compatible.
What's the difference between foil and non-foil retort structures?
– Non-foil retort packaging can be put in the micro wave.
What about taste of products in a retort
– People say that products packaged with retort
material taste fresher and maintain a more
What about shelf appeal?
– Retort pouches are more space efficient and
provide a larger surface for graphics and text.
What kind of food products can be packed in
retort packaging ?
– All kind of veg & Non- veg food products
The market for retort pouches is certainly one that
will continue to experience growth over the next few
years, as the retort pouch gets acceptable as equal to or
even superior to glass or metal containers. The pouch has
the same shelf-life as the can or the Ready-to-Cook
Products Packed in Flexible Plastic Pouches 155 jar. The
retort pouch needs to address ease of opening and re-
closing (compared to glass jars). In addition, the
packaging economics of the pack for mass volume
products will depend upon the ability to increase filling
speeds and to move from batch to continuous retort
Also, the retort pouch can save about 60% energy
while processing. Furthermore, as the product is already
sterile, it does not require additional low temperature
Thank you for your
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