This document discusses principles and methods of food preservation, specifically canning. It outlines the basic canning process which involves selecting and preparing foods, blanching, filling containers, exhausting air, sealing, heat processing, and cooling before storage. Canning uses heat treatment in hermetically sealed containers to kill spoilage microorganisms and allow foods to be stored long-term without refrigeration. Specific steps in canning mango products are also described, including pulping mangoes to make canned mango puree or slicing mangoes to make canned mango slices. Both processes involve washing, peeling, filling cans, exhausting air, sealing, heat processing, and cooling the canned products before storage.

1. Principles and Methods of
preservation
• Food preservation – Method of prevention of
decay/spoilage of food, thus allowing it to be stored
for future use and fit condition.
• How to control spoilage ?
• Methods of Preservation
1. Prevention or delay of microbial decomposition
(asepsis or absence of infection, filtration, low temp,
drying, chemicals or antibiotics, heat radiation

2. Principles and Methods of
preservation
2. Prevention or delay of self-decomposition of food
( Blanching, prevention of oxidation - antioxidant)
3. Prevention of damage by insects, animals,
mechanical causes etc.
Preservation by high Temperature -

3. Canning of F&V
• Canning is defined as preservation of foods in
hermetically sealed containers and usually
implies heat treatment as the principal factor in
prevention of spoilage.
• Canning was invented by Nicholas Appert,
• so also termed as Appertization

4. Principle and Process of Canning
Principle: Destruction of spoilage organisms within the sealed container by means of heat
Process :
1. Selection of F&V
2. Grading
3. Washing- Water, chlorine water, HVT /Steam washing
4. Peeling
5. Cutting
6. Blanching – It is also known as ------, ------ or -------
(82.2 to 93.5 degree C) – Soften the tesxture
Disadvantage – leaching of sugars and pigments- anthocyanin , Fruit lose their colour, flavour and
sugar
7. Cooling : Dip in cold water
8. Filling – Syruping/Brining
Syruping : Solution of sugar in Water – Sucrose syrup – only fruits- 20-55 B
79-82 degree C, leaving a head space-0.3to 0.5 cm
Brining – 1-3%, 79-82 degree C

5. 9. Exhausting – removal of air from cans
After filling and lidding or clinching process( lid is partially seamed), exhausting is essential.
Advantages:
• Corrosion of tin plate and pin holing
• Minimize the discolourization
• Better retention of vitamins – vit-c
• Prevents bulging of cans – hot climate/high altitude
• Prevent stress inside the cans
• Two Methods- Heating/Mechanically
• Dip in hot water ( 81-87 degree C)
• 6-10 min
• Vaccum closing – mechanical machines are also available
10. Sealing – Can sealer ( should notfall below 74 degree C)
11. Processing- fruits and acid veg ( 100 degree C) non acid veg ( 115-121 degree C)-0.7-1.05 kg/cm2) or
10-15 lb/sq inch)
12 Cooling - Cooled rapidly to about 39 Degree C ( prevent stack-burining)
13. Storage

6. Mango Pulp Canning…
Select ripe mangoes
Wash, peel
Pulping
Filling in plain cans at 85ºC (pH 3.8-4.0)
Add sugar syrup and 0.3 % citric acid (TSS 40ºBrix)
Exhausting (82-85ºC/ 6-10 min)
Double seaming
Processing (100ºC/30 min)
Cooling
Storage
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Canned mango products

7. Ripe mango fruits
Wash, peel
Cut into longitudinal slices
Filling in plain cans containing syrup (40ºBrix) and 0.3% citric acid
Exhausting (82-85ºC/ 6-10 min)
Seaming
Processing (100ºC/30 min)
Cooling
Storage
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Canned Mango Slices
Canned mango products