Izmir Institute of Technology

Department of Food Engineering

 FE 530

HEAT TREATMENT AND THERMAL PROCESSING OF FOOD

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Instructor:  Prof. Dr. Ahmet Yemenicioglu

                     Office: (232) 750 62 92

                     E-mail: ahmetyemenicioglu@iyte.edu.tr

 Prerequisite(s): Non

 Objective of the course:

Objective of the course is to teach how time-temperature conditions are set in heat treatments and thermal processes to obtain shelf stable food products.  The course also provides fundamental knowledge that may be adapted to non-thermal food preservation methods. 

 Reference Books:

Larousse, J. and Brown, B.E. (1997). Food Canning Technology. New York, Wiley-VCH.

Stumbo, C.R. (1965). Thermobacteriology in Food Processing.  New York, Academic Press

Toledo, R.T. (1999). Fundamentals of Food Process Engineering. London, Kluwer Academic/Plenum Publishers.

 Course Outline

1.  Introduction

   1.1. History of the foundation of thermal processing

   1.2. Definition of heat treatment and thermal processing           

2.  Heat treatment

   2.1. High temperature blanching

   2.2. Low temperature blanching

   2.3. Quarantine treatment

   2.4. Conditioning

   2.5. Cooking 

3. Thermal processing

   3.1.Pasteurization

   3.2.Commercial sterilization 

4. Thermobacteriology

   4.1. Determination of target microorganisms

   4.2. Classification of microorganisms important for thermal processing

   4.3. Thermal process design 

5.Thermal resistance of microorganisms

   5.1. Death of bacteria subjected to moist heat

   5.2. Calculation of thermal inactivation parameters

      5.2.1. Heat inactivation curves

      5.2.2. Decimal reduction curves

      5.2.3. Thermal death time curves 

6. Thermal resistance of enzymes

   6.1. Heat inactivation

   6.2. Heat activation

   6.3. Renaturation 

7. Calculation of lethality in different thermal processes

   7.1. Constant temperature with time

   7.2. Linear temperature gradient

   7.3. Exponential temperature rise 

8. Determination of heat penetration parameters

   8.1.Heating curves

   8.2.Cooling curves 

9. Calculation of lethality at a single point

   9.1. General method

   9.2. Graphical method

   9.3. Mathematical methods 

10. Example problems

 Grading:

midterm examination: 30 %

homework assignments: 10 %

final examination: 60 %