This slide will provide the viewer and overview about food preservation.

1. METHOD OF PRESERVING FOOD
1. Drying
one of the most ancient food preservation
techniques, which reduces water activity
sufficiently to prevent bacterial growth.

2. 2. Refrigeration
Preserves food by slowing down the growth
and reproduction of micro-organisms and the
action of enzymes which cause food to rot

3. 3. Freezing
-is the process of chilling foods to at least 0 F.
-It can be used with all foods
-True freezing is not possible in the freezer
compartment of your refrigerator where the
temperature is typically much warmer,
between 10 F to 32 F.
- Easy Method.

4. 4.Vacuum packing
A vacuum environment, usually in an air-
tight bag or bottle strips bacteria of
oxygen needed for survival, slowing
spoiling. Vacuum-packing is commonly
used for storing nuts to reduce loss of
flavor from oxidation.

5. 5.Salting/Curing.
Salt draws water through Osmosis, Prague
powder(NaNO2 + Salt) gives it a distinctive
pink colour)
Example of food where you can use prague
powder are Pork Tocino, Tapa or Cured Ham

6. 7. Smoking
Chemical components from the smoke of
burning wood:
Is a complementary process to curing that
improves flavor and appearance and can also
act as a drying agent
Most commonly subjected to this method of
food preservation are meat and fish that have
undergone curing
Fruits and vegetables like paprika, cheese
,spices, and ingredients for making drinks such
as malt and tea leaves are also smoked, but
mainly for cooking or flavoring them.
It is one of the oldest food preservation
methods, which probably arose after the
development of cooking with fire.

7. 8. ArtificiaL Food Additives
Common antimicrobial preservatives include
calcium propionate, sodium nitrate, sodium
nitrite, sulfites (sulfur dioxide, sodium bisulfite,
potassium hydrogen sulfite, etc.) and disodium
EDTA. Antioxidants include BHA and BHT. Other
preservatives include formaldehyde (usually in
solution), glutaraldehyde (kills insects), ethanol
and methylchloroisothiazolinone.

8. 9. Jellying
Food may be preserved by cooking in a
material that solidifies to form a gel.
Such materials included gelatine,agar,
maize, flour, and arrowroot flour.

9. 10.Irradiation ( exposure to X Rays, gamma rays)
Irradiation is used to reduce pathogens, increase shelf life, eliminate pests, increase
juice yield, [citation need ] delay sprouting, and improve re-hydration
It is used to as delay the ripening of fruits and the sprouting of vegetables by
slowing down the enzymatic action in food
In Austria, Germany, and many other countries of the European Union only dried
herbs, spices, and seasonings can be processed with irradiation and only at a
specific dose, while in Brazil all foods are allowed at any dose

10. 11. High Pressure processing
Is a method of preserving and sterilizing food,
in which a product is processed under very high
pressure, leading to the inactivation of certain
microorganisms and enzymes in the food .
This technique is now used there to preserve
fish and meats, salad dressing, rice cakes, and
yoghurt. An early use of pascalization in the
United States was to treat guacamole. It did not
change the guacamole's taste, texture, or color,
but the shelf life of the product increased to
thirty days, from three days without the
treatment.
However, some treated foods still require cold
storage because pascalization does not stop all
enzyme activity caused by protein, some of
which affects shelf life

11. 12.Burying in the Ground
(lack of light, oxygen,lowpH,cool temp,
dessicants in soil)
Century Eggs are created by placing eggs in
alkaline mud (or other alkaline substance),
resulting in their "inorganic" fermentation
through raised pH instead of spoiling .

12. 13. Biopreservation (addition of LAB)
In biopreservation, beneficial bacteria are
used to prevent food spoilage and get rid
of harmful pathogens. Lactic acid bacteria
(LAB) are probably the most commonly
used due to their unique properties and
because they are harmless to humans. As
LABs compete for nutrients with other
bacteria, they release antimicrobials that
stop spoilage and inhibit the growth of
potentially harmful pathogens.

13. 14. Pickling
Can be categorized in two categorize:
a. Chemical (brine,vinegar, oil)
- the food is placed in an edible liquid that inhibits or kills bacteria and other micro-
organisms. Typical pickling agents include brine (high in salt ), vinegar, alcohol , and
vegetable oil , especially olive oil but also many other oils. Common chemically
pickled foods include cucumber, pepper, cornedbeef, jeering , and eggs , as well as
mixed vegetables.
b. Fermentation (lactic acid produced by the food itself)
-this are foods produced or preserved by the action of microorganisms. In this context,
fermentation typically refers to the fermentation of sugar to alcohol using yeast, but
other fermentation processes involve the use of bacteria such as lactobacillus,
including the making of foods such as yogurt and sauerkraut.

14. 15. Addition of Lye
-NaOH prevents bacterial growth, saponifies fats
-Lye is used to cure many types of food, including lutefisk, olives (making them
less bitter), canned mandarin oranges, homminy,lye rolls, century eggs and
pretzels . It is also used as a tenderizer in the crust of baked Cantonese moon
cakes, in “zongs” (glutinous rice) dumplings wrapped in bamboo leaves), in
chewy southern Chinese noodles popular in Hong Kong and southern China,
and in Japanese ramen noodles.

15. 6.Canning and Bottling
is the process of heating the product at a
specified temperature for a specific length
of time (pasteurizing)
Vacuum sealing the pasteurized food in
special glass jars.