Gustavo V. Barbosa-Cánovas & Anthony J. Fontana 
Water Activity in Foods 
Fundamentals and Applications

Water Activity in Foods: Fundamentals and Applications is a one-of-a-kind reference text that brings together an international group of food scientists, chemists, and engineers to present a broad but thorough coverage of an important factor known to influence the attributes of foods – water activity. A team of experienced editors designed this book for lasting value as a sound introduction to the concept of water activity for neophytes and seasoned professionals in both academe and industry. Topics have been carefully selected to provide a comprehensive understanding of the mechanisms by which water activity influences the quality, shelf life, and safety of food products.

Water Activity in Foods belongs on the shelves of all food science professionals for use in product development, quality control, and food safety. Students and newcomers to these areas will appreciate the instructional approach adopted by the experienced teachers and industry specialists who have contributed chapters to this comprehensive overview.

Table of Content

Dedication ix

Preface xiii

Acknowledgments xv

List of Contributors xvii

1. Introduction: Historical Highlights of Water Activity Research 3
Jorge Chirife and Anthony J. Fontana, Jr.

2. Water Activity: Fundamentals and Relationships 15
David S. Reid

3. Water Activity and Glass Transition 29
Yrjö H. Roos

4. Water Mobility in Foods 47
Shelly J. Schmidt

5. Water Activity Prediction and Moisture Sorption Isotherms 109
Theodore P. Labuza and Bilge Altunakar

6. Measurement of Water Activity, Moisture Sorption Isotherms, and Moisture Content of Foods 155
Anthony J. Fontana, Jr.

7. Moisture Effects on Food’s Chemical Stability 173
Leonard N. Bell

8. Water Activity and Physical Stability 199
Gaëlle Roudaut

9. Diffusion and Sorption Kinetics of Water in Foods 215
Theodore P. Labuza and Bilge Altunakar

10. Effects of Water Activity (aw) on Microbial Stability: As a Hurdle in Food Preservation 239
María S. Tapia, Stella M. Alzamora, and Jorge Chirife

11. Principles of Intermediate-Moisture Foods and Related Technology 273
Petros S. Taoukis and Michelle Richardson

12. Desorption Phenomena in Food Dehydration Processes 313
Gustavo V. Barbosa-Cánovas and Pablo Juliano

13. Applications of Water Activity Management in the Food Industry 341
Jorge Welti-Chanes, Emmy Pérez, José Angel Guerrero-Beltrán, Stella M. Alzamora, and Fidel Vergara-Balderas

14. Applications of Water Activity in Nonfood Systems 359
Anthony J. Fontana, Jr., and Gaylon S. Campbell

15. The Future of Water Activity in Food Processing and Preservation 373
Cynthia M. Stewart, Ken A. Buckle, and Martin B. Cole

Appendices

A Water Activity of Saturated Salt Solutions 391
Anthony J. Fontana, Jr.

B Water Activity of Unsaturated Salt Solutions at 25°C 395
Anthony J. Fontana, Jr.

C Water Activity and Isotherm Equations 399
Anthony J. Fontana, Jr.

D Minimum Water Activity Limits for Growth of Microorganisms 405
Anthony J. Fontana, Jr.

E Water Activity Values of Select Food Ingredients and Products 407
Shelly J. Schmidt and Anthony J. Fontana, Jr.

F Water Activity Values of Select Consumer and Pharmaceutical Products 421
Anthony J. Fontana, Jr., and Shelly J. Schmidt

Index 423

About the author

Gustavo V. Barbosa-Cánovas, Ph.D., Professor of Food Engineering, Center for Nonthermal Processing of Food, Washington State University, Pullman, WA

Anthony J. Fontana, Jr., Ph.D., Senior Research Scientist, Decagon Devices, Inc., Pullman, WA

Shelly J. Schmidt, Ph.D., Professor of Food Chemistry, Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL

Theodore P. Labuza, Ph.D., Morse Alumni Distinguished Professor of Food Science and Engineering; Department of Food Science and Nutrition, University of Minnesota, Saint Paul, MN