1. Food Preservation An Overview of Methodologies

2. Food Preservation
Food preservation is the name for a number of processes that help to preserve food. For thousands of years, humans have used methods of preserving food, so that they can store food to eat later.
The simplest methods of preserving food, such as drying strips of fish or meat in the hot sun have been used for thousands of years, and they are still used.
Food preservation usually involves preventing the growth of bacteria, fungi (such as yeasts), or any other microorganisms.
Maintaining or creating nutritional value, quality and flavor is an important aspect of food preservation.

3. Food Preservation Pickling Common ways of preserving food are:
Drying: Oldest known method; 12,000 B.C.
Sun, Wind & Fire
Fire also used to dry fruits, vegetables & herbs
Modern day examples of dried preserved food:
Beef Jerky, Sun Dried Tomatoes.
Pickling
Preserve foods in vinegar or other organic acid
Lower pH inhibit bacteria and microorganisms.
Sun and wind were found to naturally dry and preserve foods
Oldest known method; 12,000 B.C.
Fire also used to dry fruits, vegetables & herbs
Wild game, fish and early domesticated animal meat were also dried
Modern day examples of dried preserved food:
Beef Jerky
Sun Dried Tomatoes 3

4. Helpful microorganisms lower pH Can make food more nutritious
Conti…
Fermenting
Helpful microorganisms lower pH
Can make food more nutritious
Examples:
Yogurt
Wine
Most Cheeses
Sugar reduces the water content
Lower pH
Cooked during the process
All of the above inhibit microorganism growth 4

5. Curing:
Salt reduces water content
The addition of Nitrites (NO2) and Nitrates (NO3) inhibit the bacteria Clostridium botulinum, which causes botulism
Smoked foods are also cured.
Freezing & Refrigeration
Freezing
Zero degrees Fahrenheit
Easiest, least time-consuming and most convenient method

6. Refrigeration
40 degrees Fahrenheit or below
Prolongs shelf life of food
Slows growth of most microorganisms but does not kill or inhibit growth
Food will eventually spoil
Canning
Extreme heating
Oxygen is driven out
Creates a vacuum seal
Two methods:
Water Boiling Canning
Pressure Canning
The method that should be used depends on the type of food and its pH

7. Foods with pH below 4.6, high acid foods 212 degrees Fahrenheit
Boiling Water Canning
Foods with pH below 4.6, high acid foods
212 degrees Fahrenheit
Kills most food spoiling/illness causing bacteria and microorganisms except Clostridium botulinum (produces toxin) which cause of Botulism (weakness, fatal illness). 7

8. Pressure Canning
Foods with ph above 4.6, low acid foods
240 degrees Fahrenheit
Only pressure canning can reach temperatures this high
Kills the bacteria, Clostridium botulinum.

9. Definition of Food Additives
A chemical added to a particular food
to preserve flavor, or enhance its taste and appearance during processing or storage which could affect the characteristics of the food, or become part of the food.

10. Introduction of Food Additives
The term food additive means any substance the intended use of which results, or may reasonably be expected to result,
directly or indirectly in its becoming a component or otherwise affecting the characteristics of any food
(including any substance intended for use in producing, manufacturing, packing, processing, preparing , treating, packaging, transporting, or holding food.

11. Introduction Food additives can be divided into two major groups
Intentional additives
Chemical substances that are added to food for specific purpose
Are regulated by strict governmental controls
Incidental additives
We have little control over incidental or unintentional additives

12. Additives uses Raise the nutrient value of food.
Prevent the formation of lump (caking) by anti caking agents (sodium aluminosillicate is used in dry milk and salts).
Bleaching agents, dough conditioners,
colouring agents,emulsifiers & stabilizers
as preservatives & prevent fats from rancidity
to slow growth of microorganisms.

13. Common Food Additives Ascorbic Acid (Vitamin C):
It is used in cereals,
cured meats & fruit
drinks as an antioxidant,
colour stabilizer or as a
nutrient
Artificial & natural flavouring:
They are used in cereals,
candy, desserts, soft
drinks &many other
foods as “mimic” of
natural flavours
Ascorbic Acid (Vitamin C)

14. Food Additives
Butylated Hydroxytoluene (BHT)
It is used cereal, chewing gum, & potato chips as an antioxidant. It keeps oils from going rancid.
Gums: (Arabic, guar, locust bean)
It is used in beverages, candy, cottage cheese, dough, drink mixes, frozen pudding, ice cream, salad dressings as stabilizers & thickening agents
. Butylated Hydroxytoluene (BHT)
. Butylhydroxytoluene

15. Food Additives Sodium Benzoate: It is used in fruit juice,
pickles, preserves
soft drinks to prevent
growth of micro
organisms in acidic foods.
Sodium Benzoate

16. THE END