Canning is a method of food preservation that involves placing food in jars and heating them to a temperature that destroys microorganisms and inactivates enzymes that could cause the food to spoil. The National Center for Home Food Preservation has a list of vegetables and vegetable products that can be canned, including asparagus, beans, beets, carrots, corn, mushrooms, and potatoes

1. CANNING
SREECHAND V NAIR

2. What do you
mean by
Canning?
Canning is a method of preserving
food in which food material are
stored in a Hermetically Sealed
Containers Canning provides a shelf
life typically ranging from one to
five years

3. Canning Process Flow Chart

4. Why Canning?
Canning inactivates enzymes
that could cause the food to
spoil
Air is driven from the jar
during heating, and as it
cools, a vacuum seal is
formed.
The vacuum seal prevents air
from getting back into the
product bringing with it
microorganisms to
recontaminate the food
Canning removes oxygen,
destroys enzymes, prevents
the growth of undesirable
bacteria, yeasts, moulds and
helps forming high vacuum in
cans.

5. History of Canning
In 1809, Nicolas Appert a French confectioner invented a process of sealing foods hermetically in a
containers and sterilizing them by heat. In honor of the inventor, canning is also known as appertizing.
Saddington in England was the first to describe a method of canningof foods in 1807. But he couldn't
put forward
In 1810, Peter Durand, another Englishman, obtained the first British Patent on canning of foods in tin
containers. In 1817, William Underwood introduced canning of fruits on a commercial scale in U.S.A.

6. Types of Canning
Water Bath Canning
Canning jars filled with prepared food are completely immersed in
boiling water for a specific period of time After processing, as the jars
becomes cool, a vacuum seal is formed. A boiling water bath can only
heat the food to the temperature of boiling water
Used for high acid food (pH 4.6 and below)
Uses boiling water temperature of 100°C
Shorter times, usually from 5 – 85 minutes
E.g. generally for all fruits, Jams and Jellies, Pickled Food, Fruits and
fruit juices, Salads

7. Pressure Canning
Canning jars filled with food are kept in a Pressure Canner(Large Pot with a
locking lid and a venting system), Pressurized steam will destroy the
bacterial spores Naturally present in these foods. As the jars cool, a
vacuum is formed, sealing the food in the jars and preventing any new
microorganisms from entering and spoiling the food.
Use for low acid food.
Uses high temperature ranging from 116°C - 121°C.
Longer times, usually from 20 - 100 minutes
 E.g. All vegetables, meats, poultry, soups etc.

8. Advantages of
Canning
•Long shelf life: Canned food can last between 2 and 5 years.
•Easy to store: Canned food is small and doesn't take up much space.
•Sustainable: Canned food doesn't need to be refrigerated or frozen.
•Maintains properties: Canned food keeps its nutritional properties and
flavor for a long time.
•Healthy: Canned food can be part of a balanced diet.
•Protects from decay: The can is a protective container that maintains
flavor and protects against microbes.
•Convenience and affordability: Canned foods are a convenient and
affordable way to incorporate more fruits and vegetables into the diet.
•Better nutrition: Research has revealed that canned foods provide the
consumers with better nutrients than frozen and even fresh food items
at lower cost.

9. Disadvantages of
Canning
High salt content-Dissolved salt is often used in the canning
process, resulting to be a major source of dietary
salt.Excessive salt consumption increases the risk of health
problems, including high blood pressure, which may boost
the risk of heart attacks and strokes.
May contain added sugar-Many varieties of fruits come
packed in light or heavy syrup, which equates to added
sugars.
Metallictaste-sometimes, the metal from the cans may leach
inside the food, causing a metallic aftertaste.

10. Previous Year Questions
Heating of Cans Can be Done
A In a boiling water bath
B Using a steamer
C In oven heat
D All the above

11. Despite efforts to eliminate spoilage organisms during canning sometimes canned foods are spoiled.
This may be due to:
A Spoilage before canning
B Under processing during Canning
C Leakage of Contaminated water through can seams during cooling
D All of The Above

12. Canning is also called as
A Appertization
B Pasteurization
C Sterilization
D Cold Sterlization

13. Statement 1: Glass packed food might be spoiled by light.
Statement 2: When canned foods with vacuum are taking onto
flights, they _____
a) True, contract
b) True, expand
c) False, contract
d) False, expand