PROCESSING OF READY TO EAT PRODUCTS

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 WHAT ARE READY TO EAT FOODS?

• Any plant/animal derived food which is offered in fresh/processed form like

frozen/shelf stable form.

• Can be Ready to cook/Ready to heat/Ready to mix/Ready to drink/Ready to

eat.

• Ranges from snack bites to meal kits.

• Eg:Fried/baked snacks, Beverages, Instant meal kits, Ready to heat meal

kits, Bakery products ,Gravies, sauces, Premixes.

• India's ready-to-eat food market stood at $261 million in 2017 and is

projected to rise to $647 million by 2023 at a CAGR of over 16 percent
during 2018-2023.

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RTE EXAMPLES

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 KEY GROWTH FACTORS OF RTE
SCOPE

• Growing urbanization, increasing rate of earning working class and per

capita spending.

• Fast-evolving urban lifestyle

• Increasing disposable income for the middle-class population

• Demand for fast food, ready to cook/mix/eat products

• Saves time and labour

• Products offering extended shelf life.

THREATS

• Lack of efficient commodity distribution system

• Mindset and negative view of the nutritional value of packaged RTE items.

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 MARKET PLAYERS

• Snacks (Extruded snacks, Chips, Namkeen): PepsiCo, ITC Foods Ltd,

Pratap Snacks, Balaji Wafers, DFM Foods, Bikanervala, Haldirams.

• Frozen foods: Apex Frozen Foods Ltd, Godrej Agrovet Ltd, ITC Ltd,

Venky’s (India) Ltd, HyFun Frozen Foods Pvt. Ltd, Innovative Foods Ltd,

Mother Dairy Fruit and Vegetable Pvt. Ltd,McCain Foods (India) Pvt. Ltd,

• Thermally processed Foods: ITC Foods Ltd, Gits Food Products Pvt. Ltd,

MTR Foods, Haldirams

• Instant foods/Ready to Cook: MTR Foods, Haldirams, Nestle.

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 CATEGORIES OF RTE
Snacks

Dairy products

Frozen

Meat products

Meal kits

Canned
CONVENIENCE FOODS

Snacks

Pasteurized

Thermally processed

Retorted

Ready to Eat Breakfast Cereals

Hot filled

Dairy Products

Shelf stable Meat Products

Ready To Cook Instant Mix/Ready to mix

Fruit drinks/health 6
Ready to Serve
drinks/soups
 RETORTING

• Known as autoclave/sterilizer, is a retort is a pressure vessel used to

“commercially sterilize” food.

• Retorting is thermal processing of low acid foods prone to microbial

spoilage in hermetically sealed containers to extend their shelf life.

• The goal is to obtain commercial sterilization by application of heat and

pressure.

• Low acid foods (i.e.: defined as products with a finished equilibrium pH

greater than 4.6 and a water activity greater than 0.85).

• Process done at temperatures at or above 250°F or 121°C.

• Batch retorts are widely used.

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 RETORT

Retort

Schematic
diagram of steam
water spray
retort

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 COMMERCIAL STERILITY
• Food safety & commercial sterility is measured by the inactivation of target
organism.

• General heat resistant organisms taken into consideration are Clostridium

botulinum and Clostridium sporonges .

• Clostridium botulinum is the target organism for all general thermal

processing systems.

• Exposure time and temperature is determined by certain calculation

parameters such as D Value,Z value and F0 value .

• “F0” is defined as the number of equivalent minutes of sterilization at 250°F

(121°C) delivered to a load (product).

• A F0 value of 3(12D) is required for achieving complete sterilization .

• Ensuring double safety, F0 of 6 is considered.

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 PROCESS PARAMETERS

Processing Parameters taken into consideration:

• Processing Time, Temperature and Pressure

• F0 value or lethality rate.

• Heat penetration studies.

Factors affecting the rate of heat transfer

• Type of process and parameter

• Equipment design

• Size ,shape and type of the package

• Product characteristic such as solid content, viscosity, particulates.

• Headspace
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 MACHINERY & UTILITIES USED
Machineries
• Kettles, unloading vessels
• Filling machine(leepack,Toyo)
• Weigh checker
• Retort, loading trays.(Retort-KM Grand,Lagarde,JBTC,Allpax.
• X-Ray/Metal detector(JBTC,Ishida)
• Drying conveyors
• Cartoning
Utilities
• Air compressor
• Boiler
• Exhaust and ventilation unit
• Cooling towers
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 MACHINERY & UTILITIES USED

Retort trays and loader

Pouch filling machine

X-Ray/Metal detector Cartoning Machine 12

 HEAT PENETRATION
• Used to determine the rate of heating & cooling of the product, to ensure safe a
thermal process.
• Validation of the process design can be done including F0
values,temp,time,pressure,cooling time etc.
• Thermocouples are used to collect data of the rate of heat transfer, used to identify
cold point.
Retort temp
Fo value of
different
pouches using
probes in a retort

Product temp using probes

probes in a retort.

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 FACTORS EFFECTING HP
Factors effecting HP studies are :
Product : Weight, formulation, preparation process, fill weight, solid to liquid ratio,
consistency, physico-chemical parameters.
Packaging type: material that the container or pouch is made of, orientation,
thickness, headspace, size and dimension,
Method of fill: Fill temp, Fill and net weight, Heat space
Sealing: Proper sealing, De aeration, vacuum.
Retort: Type of retort and operation method, come up time, tray racking systems

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 STAGES IN RETORTING

• Water fill- This differs and is an optional step depending upon the type of
retort.

• Come up- This is the first step of the process, directed to achieve the target
cook temp within the set time.

• Cook time- Sterilising the product at the designed time-temp combination

with other set conditions.

• Cool- Gradual cooling is provided post the cook step, to bring the product to
the ambient temperature.

• Drain-Water is drained by the end of the process as to the set level in the
process design

• * Sub steps within the steps are designed as per process requirement.

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 TYPES OF RETORT

There are batch and continuous type retort. Among which the widely used are

the batch retorts.

Different types of batch retorts are as below:

❖ Saturated Steam Retort Process-Direct steam Heating

❖ Water Immersion Retort (Static & Rotary)

❖ Water Spray Retort (Static & Rotary)

❖ Steam Air Retort (Static & Rotary)

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 SATURATED STEAM RETORT -DIRECT STEAM
HEATING
• Oldest steam retort type with simple design and operation

Pros Cons

Low Capital investment, particularly with Venting uses a lot of steam and is not an
carbon steel retorts economical step. Uses a lot of energy.

Inflexible – typically limited to processing

Easy to operate manually
heavy sidewall containers, such as cans.

Cannot process most fragile containers,

Can process most canned product such as pouches, plastic bottles and
plastic jar

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 WATER IMMERSION RETORT (STATIC & ROTARY)

• Like saturated steam process ,the product is completely separated from any
cooling air .
• Product is completely immersed in water.
• Air is introduced on top of water to provide overpressure.
• Sometimes air is introduced to the steam which then heats the air.
Pros Cons
Flexible and can process virtually all types Virtually impossible to operate manually,
of containers given the complexity of piping.
Can provide for a partial immersion Machines with rotary processes require
process with a rotary configuration. significantly more maintenance time and
money.
Higher Capital Investment – if a double
Best application for rotary processes more
(piggy-back style configuration) tank
than 10 RPM’s.
system is used.
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WATER IMMERSION RETORT (STATIC & ROTARY)

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 WATER SPRAY RETORT (STATIC & ROTARY)
• Uses overpressure (by introducing air during sterilization)

Pros Cons

Flexible and lower capital investment Is generally not a good option for rotary
compared to the other types of processes, particularly for those that
overpressure retorts. exceed 10 RPM’s

Energy efficient .Utilizes a heat exchanger Machines with rotary processes require
and pump to recirculate both sterilizing significantly more maintenance time and
water and cooling water. money.

Sterilizing / cooling water can be reused Extended cooling times due to indirect
without chemical treatment for the next cooling (via heat exchanger) and due to
process. water spraying.
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WATER SPRAY RETORT (STATIC & ROTARY)

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 STEAM AIR RETORT (STATIC & ROTARY)

• Uses overpressure process, except that the product is exposed to the effect of air
overpressure.
• Fan is used as a driving force to balance the steam with the air to avoid cold spots
Pros Cons

Is generally not a good option for high-RPM

Flexible and moderate capital investment
rotary processes, particularly for those that
compared to Water Immersion retorts
exceed 15 RPM’s

Energy efficient, utilizes a fan for forced Machines with rotary processes require
convection. significantly more maintenance time and
money.

Other than the addition of the fan, the The Fan is a moving part that adds to the
machine is a generally simple design and complexity / maintenance of the retort that
an easy process to administer. is unique to the Steam-Air process. 22
STEAM AIR RETORT (STATIC & ROTARY)

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 REFERENCES

• www.industrialpackaging.com
• www.researchandmarkets.com
• www.retorts.com
• www.ift.orglogy

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 National Institute of Food Technology and Entrepreneurship and
Management
Ministry of Food Processing Industries
Plot No. 97, Sector-56, HSIIDC, Industrial Estate, Kundli, Sonipat, Haryana-
131028

Website: http:www.niftem.ac.in
Email: pmfmecell@niftem.ac.in
Call: 0130-2281089

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