The document discusses the process of canning food. It was invented in 1809 by Nicolas Appert as a way to preserve food for military use. Canning involves sealing food in air-tight containers and applying heat to kill microorganisms and allow long-term storage. Common foods canned include fruits, vegetables, meats, and other products. The canning process destroys pathogens, inactivates enzymes, and prevents recontamination to provide a shelf life of one to five years.

1. CANNING
SUBMITTED BY : AMRUTHA .K
SUBMITTED TO : PROF D . S BUNKAR
MSC 1ST YEAR
REG NO : 22412FST002
DEPARTMENT OF DAIRY SCIENCE AND FOOD TECHNOLOGY
IAS,BHU

2. The process was invented after prolonged research
by Nicolas Appert of France (Father of canning) in 1809, in
response to a call by his government for a means of
preserving food for army and navy use.
1810 -Peter Durand replaced the breakable glass bottle
with cylindrical tinplate canister.
Louis Pasteur provided the explanation for canning when
he was able to demonstrate that the growth of
microorganism is the cause of food spoilage

3.  The process of sealing fruits and vegetables or any other foodstuffs hermetically
(air tight) in containers and sterilizing them by heat for long storage is known as
canning.
CANNING
 The process of canning is also known as Appertization.
 Canning provides a shelf life of typically ranging from one to five years ,although
under specific circumstances it can be much longer.
 Heating is the principle factor to destroy the microorganisms and the permanent
sealing is to prevent re- infection.

4. PURPOSE OF CANNING
Pathogens and food-spoiling bacteria are destroyed and the
enzymes in the food are inactivated
Canning keeps food sterile for long periods hence, the shelf life
of canned food is usually longer. (freeze-dried canned product
last long as 30 year )
 The idea is to make food available and edible long after the processing
time. Using jars or containers and heating them to a temperature that
destroys micro-organisms that cause food to spoil.
 Make food available in offseason.
 The process of cleaning, packaging, and sanitizing the produce
uses low amounts of energy and water. The overall canning
process saves energy, reduces food waste and helps seal in
nutrients.

5. FOOD THAT ARE CANNED
 Low acid foods: Meat, fish, poultry, dairy fall into a pH range of 5.0 to 6.8.
This large group is commonly referred to as the low acid group
 Acid foods: With pH values between 4.5 and 3.7. Fruits such as pear,
oranges, apricots and tomatoes fall in this class.
 High acid foods: Such as pickled products and fermented foods. The pH
values range from 3.7 down to 2.3, also Jams and Jellies are in
this classification.

6. CANNING METHODS
 Canning can be done by two methods
boiling water bath method and the pressure
canner method
1. Water Bath Canning
Used for high acid food (PH 4.6 and below)
Uses boiling water temperature of 100o c
Shorter time ,usually from 5-85 minutes
Eg: generally for all fruits

7. 2.PRESSURE CANNING
 Uses high temperature ranging
from 116°C - 121°C.
 Longer times, usually from 20 -
100 minutes
 E.g. generally all vegetables,
meats, poultry, soups etc.
Used for low acid food

8. CONTAINER FOR PACKING THE CANNED PRODUCTS
The container plays a vital role in food canning, it must be
1) Capable of being hermetically sealed to prevent entry of microorganisms
2) Impermeable to liquids and gases, including water vapour
3) Maintain the state of biological stability (i.e., commercial sterility) that was
induced by the thermal process alone or in combination with other chemical and
physical processes
4) Physically protect the contents against damage during transportation, storage
and distribution

9. Both tin and glass containers are used in the canning industry, but tin containers are
preferred.
 Tin containers
Tin cans are made of thin steel plate of low carbon content, lightly coated on both
sides with tin metal.
The contents of the can may react with these uncoated surface resulting in
discolouration of the product or corrosion of the tin plate.
It is necessary, therefore, to coat( thickness 0.31mm-1.54mm) the inside of the can
with some material (lacquer) which prevents discolouration but does not affect the
flavour or wholesomeness of the contents. This process is known as "lacquering".

10. To prevent the discoloration lacquering is done. Two types of lacquers:
 Acid resistant
can coated with this, called R-enamel or A.R cans.
meant for high acid food commodity (rasberry, strawberry, apricot etc.)
 Sulphur resistant
can coated with it know as C-enamel Or S.R cans.
 meant for low acid foods (peas, corn, beans)
 Lacquers include oleo-resinous material, synthetic resin, phenolic resins, epoxy
resin and vinyl resins

11. GENERAL STEPS FOR CANNING

13. PROCESS
1.Selection of fruits and vegetables
 Fruits and vegetables should be absolutely fresh.
 Fruits should be ripe, but firm, and uniformly mature. Over-ripe fruits should be
rejected because they are infected with microorganisms and give a poor quality
product. Unripe fruits should be rejected because they generally shrivel and
toughen on canning.
 All vegetables except tomatoes should be tender. Tomatoes should be firm, fully
ripe and of deep red colour.
 Fruits and vegetables should be free from dirt. They should be free from
blemishes, insect damage or mechanical injury.

14. 2. Grading
 The selected fruits and vegetables are graded according to size and colour
to obtain uniform quality.
 This is done by hand or by machines such as screw grader and roller
grader.
 Fruits like berries, plums and cherries are graded whole. while peaches,
pears, apricots, mangoes, pineapples, etc., are generally graded after
cutting into pieces or slices.

15. 3. Washing
 "It is important to remove pesticide spray residue and dust from fruits and vegetables.
 Fruits and vegetables can be washed in different ways. Root crops that loosen in soil
are washed by soaking in water containing 25 to 50 ppm chlorine (as detergent).
 Vegetable may preferably be soaked in dilute solution of potassium permanganate.
 Other methods of washing are spray washing, steam washing, etc.

16. 4. Peeling
 The objective of peeling is to remove the outer layer. Peeling may be done in various
ways
 Hand peeling : done in case of fruits with irregular shape
 Steam peeling : by using boiling water or steam
 Mechanical peeling : done in potatoes and carrot
 Lye peeling : done by dipping in 1-2% boiling caustic soda solution for 30 sec – 2 min
 Flame peeling : used only for onion and garlic which have papery outer cover.

17. 5. Cutting
Pieces of the size required for canning are cut. Seed, stone and core are removed.
Some fruits like plum from which the seeds cannot be taken out easily are canned
whole.
6. Blanching
 Blanching is Usually done in case of vegetables by exposing them to boiling water or
steam for 2 to 5 minutes, followed by cooling.
 Inactivates most of the plant enzymes which cause toughness, discoloration
(polyphenol oxidase). mustiness, off-flavour (peroxidase), softening and loss of
nutritive value.- Reduces the number of microorganisms by as much as 99%.

18. 7. Cooling
After blanching, the vegetables are dipped in cold water for better handling and keeping
them in good condition
8. Filling
Before filling, cans are washed with hot water and sterilized ,After filling, covering with
syrup or brine is done and this process is called syruping or brining. Headspace left
inside ranges from 0.32 cm to 0.47 cm.
 Syruping
 A solution of sugar called a syrup (white refined sugar commonly used)
 Done in case of fruits
 Improve flavour
 Serve as a heat transfer medium to facilitating processing
 Concentration – 20-55 % brix
 Fruit high in acid require a more concentration syrup than less acid one.
 Syrup should be filled at about 79-820c

19. Brining
 Solution of salt in water called brine
 Done in case of vegetables
 Common salt of good quality are used
 Hot brine of 1-2 % concentration used
 Brining at a temperature 79- 820c

20. 9. Lidding
 After syruping or brining the cans are loosely covered with lid
 Modernised by clinching process in which lid is partially seamed to can.

21. 10. Exhausting
The process of removal of air from cans is known as exhausting. After filling and lidding or
clinching, exhausting is essential. The major advantages of exhausting are as under
 Corrosion of the tinplate and pin holing during storage is avoided.
 Minimizes discoloration by preventing oxidation.
 Helps in better retention of vitamins particularly vitamin C.
 Reduce chemical reaction between container and the content.
 Prevents development of excessive pressure and strain during sterilization
Exhausting methods:
 Thermal exhausting (Steam Vacuum)
 Mechanical Exhausting (Machine Vacuum)

22. 11. Sealing
Immediately after exhausting the cans are sealed airtight by means of a can
sealer.In case of glass jars a rubber ring should be placed between the mouth of
the jar and the lid, so that it can be sealed airtight. During sealing the temperature
should not fall below 74°C.
12. Processing
Heating of foods for preserving is known as processing. The cans must be processed
(heat treated) immediately after closing (hermetic sealed) at suitable time and
temperature.
 Food to be canned is threatened on the one hand by bacterial spoilage (if under
processed) and on the other by loss of nutritive quality by over heating.
 Vegetative bacteria are killed at 800 /30 min
 Spore formers at a temp 1100 c /30 min
 For destroying the spore 121oc/3min

23. RATE OF HEAT PENETRATION IN PROCESSING
 Type of product
 Size of container
 Agitation of the container
 Temperature of the retort
 Shape of container
 Type of container
Heat penetration into a can of conductive
heating food

24. 13.Cooling
 Immediately after processing, the cans are cooled in water to a temperature of 36°C to
42°C to avoid thermophilic spoilage or can rust.
 If the cans are cooled much below 36°C, they may not dry thoroughly and rusting well
result.
 If the cans are cased at temperatures much over 42°C, thermophilic spoilage may occur
14. Storage
 After labelling the cans, they should be packed in strong wooden cases or corrugated
cardboard cartons and stored in a cool and dry place.
 The outer surface of the cans should be dry as even small traces of moisture
sometimes induce rusting.
 Storage of cans at high temperature should be avoided, as it shortens the shelf-life of
the product and often leads to the formation of hydrogen swell.

25. CONTAMINATION OF CANNED FOOD
 MICROBIAL SPOILAGE
 Due to survival of microbes and spores after heat treatment
 Mechanical damage cause leakage which permit the entry of microbes
 Rough handling of filling
 No proper storage.
 Flat sour spoilage
 Mainly occurs in low acid food
 Caused by the species of Bacillus such as Bacillus stearothermophillus,
Bacillus coagulans.
 Ends of the can remain flat during souring or development of lactic acid in the
food ,no production of gas.

26.  Thermophilic anaerobic (TA) spoilage
 caused by thermophilic anaerobes not producing hydrogen sulfide.
 Clostridium thermosaccharolyticum is the main organism involved.
 Produce acid and gas in food
 Spoiled food produce sour and cheesy smell
 Sulphur stinker spoilage
 Desulfotomaculum nigrificans is the main organism involved
 Spore of this organism is generally heat resistant than those of flat sour
and TA bacteria.
 Therefore ,spoilage by this organism indicates inadequate heat treatment
during canning.
 Organism produce hydrogen sulphide which react with tin of can and black
spot formed in food and inner wall.

27.  Spoilage by yeasts
 Presence of yeast is the result of either underprocessing or leakage
 Cause swelling by the production of carbon dioxide.
 Canned fruits, jams, jellies, fruit juice etc have been spoiled by fermentative
yeast like Saccharomyces cerevisiae , Saccharomyces pastorianus
 Spoilage by mould
 Aspergillus and penicillium are the most spoiling organism
 Moulds are more common in home canned food where heating and sealing
are not under total aseptic condition.
 Can grow at high sugar concentration
 Acidification is the prevention method to prevent growth of mould.

28. Soft Swell: A can that is bulged on both ends, but not so tightly that the ends can't be
pushed in somewhat with a thumb press
Hard Swell: A can that is so tightly bulged on both ends that the ends can't be pressed in
Flipper: A can whose end normally looks flat, but "flips out" when struck sharply on one
end.
Springer: A can with one end bulged out. With sufficient pressure, this end will flip in, but
the other end will flip out.
Leaker: A can with a crack or hole in the container that has caused leakage.
breather: A can with minute leak that permit air to move in or out
APPEARANCE OF CAN
 CHEMICAL CAUSE
 Caused by hydrogen swell due to the presence of hydrogen gas released by
increase acidity , increase temp, a poor exhaust, inadequate lacquering of interior of
can, presence of soluble sulphurs and phosphorous compound.

29. ADVANTAGE OF CANNING
•Helps save money
•Saves nutritional value
•Can last for years
•Does not require electricity or refrigeration to store
•Preservative- and pesticides-free food
•Offseason availability
DISADVANTAGE OF CANNING
•Time-consuming process
•Initial startup cost of buying the equipment
•Person should know which foods are high risk and
which are low
•Change in ingredient may require a change in
processing
•Canning machines are expensive

30. CONCLUSION
 Canning is an important, safe method of food preservation if practiced properly. The
canning process involves placing foods in jars and heating them to a temperature
that destroys microorganisms that could be a health hazard or cause the food to
spoil
 Canning can be a safe way of preserving and storing food for a prolonged period of
time. However, if not done properly, it can result in serious illness and can have fatal
consequences. It is important to understand the science of canning and implement
proper control measures to ensure the safety of canned products.
 Canning alters food chemically by changing the moisture, pH, or salinity
levels to protect against microbes, bacteria, mold, and yeast. It also limits food
enzyme activity. Combining these chemical processes with the physical barriers of
glass jars, seals, and lids effectively prevent decay.

31. REFFERENCE
 Lal, G., & Siddappa, G. S. (1959). Preservation of fruits and vegetables (No. 664.828
L35).
 Featherstone, S. (Ed.). (2015). A complete course in canning and related processes:
Volume 3 Processing Procedures for Canned Food Products. Woodhead Publishing.
 Deák, T., & Farkas, J. (2013). Microbiology of thermally preserved foods: canning and
novel physical methods. DEStech Publications, Inc.
 Teixeira, A. A. (2014). Thermal food preservation techniques (pasteurization,
sterilization, canning and blanching). Conventional and advanced food processing
technologies, 115-128.
 http://www.slideshare.net/
 https://www.researchgate.net/
 http://www.fnbnews.com/Top-News/canning-of-fruits-and-vegetables-38522
 http://ecoursesonline.iasri.res.in/mod/resource/view.php?id=5822

32. THANK YOU