The Microwave Processing of Foods

Marc Regier, Kai Knoerzer, Helmar Schubert

• Publisher: Woodhead Publishing
• Year: 2016
• Edition: 2
• eBook ISBN:
  9780081005316
• Topic: Technology & Engineering
• Subtopic: Food Science
• Index: Technology & Engineering

The Microwave Processing of Foods, Second Edition, has been updated and extended to include the many developments that have taken place over the past 10 years. Including new chapters on microwave assisted frying, microwave assisted microbial inactivation, microwave assisted disinfestation, this book continues to provide the basic principles for microwave technology, while also presenting current and emerging research trends for future use development. Led by an international team of experts, this book will serve as a practical guide for those interested in applying microwave technology. - Provides thoroughly up-to-date information on the basics of microwaves and microwave heating - Discusses the main factors for the successful application of microwaves and the main problems that may arise - Includes current and potential future applications for real-world application as well as new research and advances - Includes new chapters on microwave-assisted frying, microbial inactivation, and disinfestation

1

Introducing microwave-assisted processing of food

Fundamentals of the technology

M. Regier¹, K. Knoerzer² and H. Schubert³, ¹Trier University of Applied Sciences, Trier, Germany, ²CSIRO Agriculture and Food, Melbourne, VIC, Australia, ³Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany

Abstract

In this chapter, microwaves are introduced as a type of electromagnetic waves of frequencies between 300 MHz and 300 GHz. The “technical” microwaves used for processing are regulated by the ISM bands and by certain maximum emission levels and exposure limits of humans. Theoretical aspects of the electromagnetic theory, starting from Maxwell’s and the constitutive material equations, over the general wave equations to exemplary solutions like the plane wave, the exponentially damped wave and Fresnel’s reflection formulas are discussed. Finally, the general configuration and operation of microwave processing systems, consisting of a microwave source (still in most cases the magnetron), a waveguide and an applicator are presented.

Keywords

Microwave basics; electromagnetic waves; microwave processing systems; microwave source

1.1 Introduction

The following chapter covers the fundamentals of microwaves, the corresponding physical theory, as well as some general remarks and considerations on the setup of microwave applications. First, the definition of frequency and wavelength ranges, and legislative regulations of frequency bands are discussed. Then, the basic equations, i.e., Maxwell’s equations and the equations describing the interaction of electromagnetic waves with matter, are introduced. Starting with these basics, the wave equation and some exemplary solutions are derived, and the important concept of the penetration depth and power absorption, which is useful for the estimation of thermal microwave–matter interaction, can be introduced. After covering the general setup and configuration of microwave applications, consisting of microwave sources, waveguides, and applicators, the chapter is completed by useful links to further literature on this topic.

1.2 Physical definitions and legislative regulations

1.2.1 Definition

Microwaves are electromagnetic waves within a frequency ban...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• List of contributors
• About the editors
• Preface
• Woodhead publishing series in food science, technology and nutrition
• 1. Introducing microwave-assisted processing of food: Fundamentals of the technology
• 2. Microwave heating and the dielectric properties of foods
• 3. Determination of the dielectric properties of foods
• 4. Impact of microwave processing on nutritional, sensory, and other quality attributes
• 5. Microwave technology for food processing: An overview of current and future applications
• 6. Microwave-assisted baking
• 7. Microwave-assisted frying
• 8. Microwave-assisted drying
• 9. Microwave-assisted blanching
• 10. Microwave-assisted pasteurization and sterilization—commercial perspective
• 11. Microwaves for microbial inactivation—efficiency and inactivation kinetics
• 12. Microwave-assisted thawing and tempering
• 13. Packaging for microwave foods
• 14. The heating performance of domestic microwave ovens
• 15. Measuring temperature distributions during microwave processing
• 16. Microwave plant requirements and process control for advanced applications
• 17. Improving the heating uniformity in microwave processing
• 18. Simulation of microwave processes
• Index