food preservation methods with details and different types of microorganisms and how to control them all are discribed in slides.

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2. Department of Food
Science & Nutrition
Swl
Campus
BY MUHAMMAD ADNAN 03035044643
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Presentation
Topic Preservation Methods

3. What is Food Preservation:
 Defination:
“Food Preservation Known as Science which deals with the
process of prevention of deterioration or spoilage of food .
Allowing it to be Stored in a fit condition”
 Objectives of Food Preservation:
 It ensure the Quality.
 It ensure edibility and nutrition value prevention of growth
of bacteria and other microbes.
 It ensure the shelf life.
 Retard oxidation and rancidity.
 It ensure that no coloring Material.
 It is a good step to food security.
 Safe food from any type of waste.
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4. Preservation Methods:
1. High Temperature.
i. Blanching
ii. Pasteurization
iii. Sterilization
iv. UHT(Ultra Heat Treatment)
1. Low Temperature.
i. Refrigeration
ii. Freezing
iii. Drying
iv. Dehydration
v. Spray Drying
vi. Smoking
vii. Salting/Pickling
viii. Canning
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5. 1.High Temperature
i. Blanching.
“Blanching is a heat treatment method In which is food is heated in hot
water( Temperature is 100`C) for specific period of time to inactive the food
enzymes”
 Objective of Blanching Method.
 To kill Micro-organisms.
 To loosen the skin(eg Tomatoes)
 To inactivate the enzymes
 Fix the green color in vegetables(peas, spinach)
 To reduce size.
 Remove Tissue gas from leafy vegetables(e.g spinach).
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6. ii. Pasteurization:
 Defination.
“Pasteurization is a Heat treatment method which is used to kill pathogenic
Bacteria from liquid food(Milk/Juice) at 65-88`C temperature”
 In Milk, used to kill Tb Causing bacteria known as mycobacterium
tuberculosis
 Temperature varies with nature or type of food + length of time exposure.
 (This method was invented by Louis Pasteur, a French chemist, in 1862)
 Purpose
 To increase the shelf-life of product.
 To increase milk safety for the consumer by destroying disease
causing microorganisms (pathogens) that may be present in milk.
 To increase keeping the quality of milk products by destroying
spoilage microorganisms and enzymes that contribute to the
reduced quality and shelf life of milk.
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7. Types of Pasteurization
i. Continuous Pasteurization
ii. Discontinuous Pasteurization
1. Continuous Pasteurization.
 Consist of single metal tube or series of hollow jacketed plates or
small metal tubes.
 Liquid food passing through jacketed which provide heat
treatment to the liquid(Milk)
 Jacketed consist of steam hot water.
 Further types.
1. LTLT
2. HTST
3. UHT
 LTLT(Low Temperature for long time)
LTLT temperature for juices is 65-75`C for 20 minutes.
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8. • HTST(High Temperature for short time)
 HTST is used for Milk and juices.
 For Milk(72`C for 15 Seconds)
 For Juices(82`c to 91`C for few seconds)
 HTST is the best hear treatment method for heating because at
this temperature Nutrition value of liquid does not loss.
 UHT(Ultra High Temperature)
 UHT also called Flash Pasteurization
 The fruit juice heated at 116`C and cooled at 88`C before
filling.
2. Discontinuous Pasteurization.
 Consist of steam jacketed kettle or tank equipped with steam
coils in which food(juice/Milk) may be placed and heated to
the according temperature to required length of time.
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9. iii. Sterilization
 Defination
“Sterilization is a food preservation method in which food is
heated at 121`C for few minutes to kill the clostridium bacteria”
 Objectives
 To increase the shelf-life of food
 To save the food from the clostridium bacteria.
 To improve Quality of food.
UHT(Ultra High Temperature)
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10. 4.UHT(Ultra High Temperature)
 Defination
“UHT is the heat treatment method which is used
to kill the Botulism Bacteria At 141`C temperature
for few seconds”
 Advantages:
 You can store it at room temperature (as long as it is
unopened) for extended periods
 You have milk readily available
 It has a smooth, creamy taste and texture
 Naturally high in calcium
 To increase the shelf-life of food.
 The shelf-life of UHT Milk is 60-90 days.
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11. Thank you..!!
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12. AnY Question??
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