Thermal Food Processing

12
CONTENTS
Thermal Processing
of Ready Meals
Gary Tucker
12.1 Introduction ...........................................................................................363
12.2 Methods of Manufacture .......................................................................365
12.2.1 Nonthermal Methods for Manufacturing Ready Meals..........366
12.2.1.1 Freezing ...................................................................367
12.2.1.2 Chilling....................................................................367
12.2.1.3 Drying and Water Activity Control.........................368
12.2.1.4 Modifying the Atmosphere .....................................368
12.2.2 Preservation by Thermal Processing .......................................369
12.2.3 In-Vessel Systems ....................................................................371
12.2.4 Heat Exchangers ......................................................................372
12.2.5 In-Pack Retorting.....................................................................374
12.3 Ensuring Ready-Meal Safety ................................................................376
12.3.1 Temperature Probe Systems ....................................................378
12.3.2 Microbiological Methods for Process Validation....................379
12.3.3 Time–Temperature Integrators (TTIs) .....................................380
12.4 Future Trends.........................................................................................381
12.4.1 High-Pressure Processing ........................................................381
12.4.2 Ohmic Heating.........................................................................382
12.4.3 Microwave Processing .............................................................382
12.4.4 Irradiation.................................................................................382
12.5 Conclusions ...........................................................................................383
References .........................................................................................................384
12.1 INTRODUCTION
This chapter considers thermal processing of ready meals in terms of the different
types of meals on the market, their methods of manufacture, and the assurance of
quality and safety of those meals. Temperature, referred to as thermal processing,
is the most commonly used method to kill or control the numbers of microorganisms
present within foods and on packaging material surfaces. Other methods for achieving
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