Introduction to food preservation methods

1. Industrial and Food microbiology
Principles and methods of food
preservation and food sanitation
By
Ms. Arti Kumari
Assistant professor
Department of Microbiology
Patna Women’s college

2. Arti Kumari (Assistant professor), Department of Microbiology, Patna Women’s College
Food Preservation
• Food preservation, any of a number of methods by which food is
kept from spoilage after harvest or slaughter.
• Among the oldest methods of preservation are drying, refrigeration,
and fermentation. Modern methods
include canning, pasteurization, freezing, irradiation, and the addition
of chemicals.
• Advances in packaging materials have played an important role in
modern food preservation.

3. Arti Kumari (Assistant professor), Department of Microbiology, Patna Women’s College
Why Food Preservation is needed????
Food
spoilage
• Changes in food that renders it unfit for
consumption
Factors of
food
Spoilage
•BIOLOGICAL CHANGES
• Contamination by Microorganisms
• Infestation by insects
• Degradation by endogenous enzyme
Factors of
food
Spoilage
•PHYSICAL AND CHEMICAL CHANGES
• Tearing of plant or animal tissues
• Oxidation of certain constituents of food

4. Arti Kumari (Assistant professor), Department of Microbiology, Patna Women’s College
Principles of Food preservation
Preventionofdelayof
microbialdecomposition
• By keeping out
microorganisms
(Asepsis)
• By removal of
microorganisms
• By hindering
the growth and
activity of M.Os
Preventionofdelayofself
decomposition
• By destruction
of inactivation
of food
enzymes
• By prevention
or delay of
purely chemical
reactions
Preventionofdamagebecauseof
insects,animals,mechanicalcauses
• Not discussed
here

5. Arti Kumari (Assistant professor), Department of Microbiology, Patna Women’s College
Methods of
Food
Preservation
Maintenance of
anaerobic
conditions
Combination of
two or more of
these methods
Irradiation
Use of Chemical
Preservatives
Drying Use of Low
temperature Asepsis (Keeping
out
microorganisms)
Use of high
temperature
Removal of
Microorganisms
Mechanical
destruction of
Microorganisms

6. Arti Kumari (Assistant professor), Department of Microbiology, Patna Women’s College
Methods of preservation of food
Methodoffood
preservation Physical Method
Aseptic packaging
Irradiation
Low temperature
high temperature
Chemical method
Salt
Sugar
Benzoate
Citric acid
Ethylene oxide
Nitrate and nitrite

7. Arti Kumari (Assistant professor), Department of Microbiology, Patna Women’s College
Classification of food preservation and processing
methods

8. Arti Kumari (Assistant professor), Department of Microbiology, Patna Women’s College
Methods of preservation from microorganisms
Preservation
from Micro-
organisms
Reduction of pH
Control of
oxygen and
CO2
concentrations
Lowering of
temperature
during Storage
Removal of
water
Application of
heat
Removal of
nutrients
needed for the
growth
Use for
chemical to kill
or reduce the
growth of M.Os

9. Arti Kumari (Assistant professor), Department of Microbiology, Patna Women’s College
Classification of Preservation factors
Mode of Action Preservation factor Mode of achievement
Inactivation of
microorganisms
Heat
Radiation
Pasteurization
Sterilization
Radicidation
Radurization
Radappertization
Inhibition or slowing of
growth of
Microorganisms
• Cool
• RestrictWater
• Restrict oxygen
• Increase CO2
• Alcohol
Chill
Freeze
Dry
Add Salt
Add sugar
Add Glycerol
Add other Solutes or use
combination of the above
Vacuum Pack
Nitrogen pack
CO2 pack
Fermentation
fortification

10. Arti Kumari (Assistant professor), Department of Microbiology, Patna Women’s College
Mode of Action Preservation factor Mode of achievement
Acidity
Add preservatives
Add acids
Lactic acid fermentation
Acetic acid fermentation
Restriction of access of
microorganisms to product
Microstructure control
Decontamination
Aseptic or clean handling
Packaging
Emultion
Ingredients
Packaging materials, eg by
chemicals (HCl, H2O2)heat,
irradiation (ionizing or X;
nonionizing)
Super clean processing
Aseptic processing
Aseptic or clean packaging
Source: could et al. (1983)

11. Arti Kumari (Assistant professor), Department of Microbiology, Patna Women’s College