Food preservation techniques were developed by ancient cultures to safely store food supplies and diminish the need to constantly hunt and gather. Proper preservation prevents pathogenic bacterial growth, maintains food quality by inhibiting spoilage, and saves money by extending a food's expiration date. Common preservation methods include temperature control through cooling, freezing and boiling, curing meat via drying, salting and smoking, and fermenting foods using pickling and sugaring. Modern techniques also utilize canning, pasteurization, irradiation and adding preservative chemicals.

1. Food Microbiology
(2+1)
Urooj Bakht
FOST, UCP
1

3. Background:
• Ancient cultures around the globe accidentally discovered and purposefully
invented techniques to preserve foods, including cooling, freezing, boiling,
drying, salting, smoking, pickling, and sugaring.
• Food historians believe that food preservation, along with agriculture, enabled
human societies to form once food supplies could be safely stored in bulk,
thereby diminishing the need to nomadically hunt and gather for sustenance.
• Rather than have to consume the kill or harvest immediately, preservation
allowed for planning ahead for periods of potential hunger (for example,
drought or winter).

4. Reasons behind food preservation
•To minimise pathogenic bacteria:
Food in long-term storage is at serious risk of spoilage due
to bacteria such as E. coli, Salmonella, and other
pathogens. Bacteria only need warmth, moisture, and time
to rapidly multiply in food, but food preservation inhibits
one or more of these conditions and stops their growth.

5. •To keep food at its best quality:
Food deteriorates over time due to spoilage. In many
cases, mild spoilage doesn’t make food unsafe to eat,
but it significantly affects its taste, texture, and
appearance. Proper food preservation can help retain
some of these qualities, as well as the nutritional
value of certain foods.

6. •To save money :
Waste is costly, both at home and in a commercial
setting. Ideally, you should avoid buying more than you
can use, but various preservation methods – if done
safely – help you keep vegetables, fruits, meat, etc. well
past their usual expiration so there’s no need to bin
them.

8. Types of Food Preservation:
➢Temperature Control: Cooling, Freezing, and Boiling.
➢Curing Meat: Drying, Salting, and Smoking.
➢Fermentation: Pickling and Sugaring.
➢Modern methods include canning, pasteurization, freezing,
irradiation, and the addition of chemicals.

15. Preservatives
A preservative is a substance or a chemical that is added to
products such as food products, beverages, pharmaceutical drugs,
paints, biological samples, cosmetics, wood, and many other
products to prevent decomposition by microbial growth or by
undesirable chemical changes.