Water Activity in Foods

This second edition of Water Activity in Foods furnishes those working within food manufacturing, quality control, and safety with a newly revised guide to water activity and its role in the preservation and processing of food items. With clear, instructional prose and illustrations, the book’s international team of contributors break down the essential principles of water activity and water–food interactions, delineating water’s crucial impact upon attributes such as flavor, appearance, texture, and shelf life.

The updated and expanded second edition continues to offer an authoritative overview of the subject, while also broadening its scope to include six newly written chapters covering the latest developments in water activity research. Exploring topics ranging from deliquescence to crispness, these insightful new inclusions complement existing content that has been refreshed and reconfigured to support the food industry of today.

Dedication v

Preface to the Second Edition ix

Preface to the First Edition xi

List of Contributors xiii

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

2. Water Activity: Fundamentals and Relationships 13
David S. Reid

3. Water Activity and Glass Transition 27
Yrjö H. Roos

4. State and Supplemented Phase Diagrams for the Characterization of Food 45
Yrjö H. Roos

5. Water Mobility in Foods 61
Shelly J. Schmidt

6. Water–Solid Interactions in Food Ingredients and Systems 123
Lisa J. Mauer

7. Water Activity Prediction and Moisture Sorption Isotherms 161
Theodore P. Labuza and Bilge Altunakar

8. Measurement of Water Activity, Moisture Sorption Isotherm, and Moisture Content of Foods 207
Anthony J. Fontana, Jr. and Brady P. Carter

9. Moisture Effects on Food’s Chemical Stability 227
Leonard N. Bell

10. Water Activity and Physical Stability 255
Gaëlle Roudaut

11. Enthalpy Relaxation and Food Stability 271
Roopesh M. Syamaladevi, Shelly J. Schmidt, Gustavo V. Barbosa‐Cánovas, and Shyam S. Sablani

12. Diffusion and Sorption Kinetics of Water in Foods 287
Theodore P. Labuza and Bilge Altunakar

13. Applications for Dynamic Moisture Sorption Profiles in Foods 311
Brady P. Carter

14. Effects of Water Activity (aw) on Microbial Stability as a Hurdle in Food Preservation 323
María S. Tapia, Stella M. Alzamora, and Jorge Chirife

15. Baroprotective Effect from Reduced aw 357
Avelina Franco‐Vega, Fátima Reyes‐Jurado, Nelly Ramirez‐Corona, Enrique Palou, and Aurelio Lopez‐Malo

16. Principles of Intermediate‐Moisture Foods and Related Technology 385
Petros S. Taoukis and Michelle Richardson

17. Desorption Phenomena in Food Dehydration Processes 425
Gustavo V. Barbosa‐Cánovas and Pablo Juliano

18. Humidity Caking and Its Prevention 453
Micha Peleg

19. Selected Applications of Water Activity Management in the Food Industry 465
Zamantha Escobedo‐Avellaneda, Verónica Rodriguez‐Martínez, Vinicio Serment‐Moreno, Gonzalo Velázquez, Jorge Welti‐Chanes, and J. Antonio Torres

20. Water Relations in Confections 483
Jade McGill and Richard W. Hartel

21. Applications of Probabilistic Engineering in Food Moisture Management to Meet Product Quality, Safety, and Shelf‐Life Requirements 501
Verónica Rodriguez‐Martínez, Gonzalo Velázquez, Jorge Welti‐Chanes, and J. Antonio Torres

22. Applications of Water Activity in Nonfood Systems 521
Anthony J. Fontana, Jr. and Gaylon S. Campbell

23. The Future of Water Activity in Food Processing and Preservation 535
Cynthia M. Stewart, Kenneth A. Buckle, and Martin B. Cole

Appendices

A Water Activity of Saturated Salt Solutions 553
Anthony J. Fontana, Jr.

B Water Activity of Unsaturated Salt Solutions at 25°C 557
Anthony J. Fontana, Jr.

C Water Activity, Isotherm, and Glass Transition Equations 561
Anthony J. Fontana, Jr. and Shafiur Rahman

D Minimum Water Activity Limits for Growth of Microorganisms 571
Anthony J. Fontana, Jr.

E Water Activity Values of Select Food Ingredients and Products 573
Shelly J. Schmidt and Anthony J. Fontana, Jr.

F Water Activity Values of Select Consumer and Pharmaceutical Products 593
Anthony J. Fontana, Jr. and Shelly J. Schmidt

Index 595

GUSTAVO V. BARBOSA-CÁNOVAS is Professor of Food Engineering and Director of the Center for Nonthermal Processing of Food at Washington State University, Pullman, WA, USA.

ANTHONY J. FONTANA, JR. is Technical Services Manager, ALS Global USA, Corp., Irvine, CA.

SHELLY J. SCHMIDT is Professor of Food Chemistry in the Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, USA.

THEODORE P. LABUZA is Morse Alumni Distinguished Professor of Food Science and Engineering in the Department of Food Science and Nutrition at the University of Minnesota, Saint Paul, MN, USA.

Understand how water activity can determine food quality with this exhaustive guide

This second edition of Water Activity in Foods: Fundamentals and Applications brings together an international group of food scientists, food engineers, food chemists and food microbiologists to examine the fundamental aspects of water activity and its relationships with glass transition theory, moisture content, sorption isotherms leading to better understand how water activity affects microbial growth, chemical/enzymatic reaction rates, physical properties, moisture gain and loss in packages, water activity as a hurdle.

The updated and expanded second edition continues to offer an authoritative overview of the subject, while also broadening its scope to include nine newly written chapters covering the latest developments in water activity research. Exploring topics ranging from deliquescence to crispness, these insightful new inclusions complement existing content that has been refreshed and reconfigured to support the food industry of today. 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. Other approaches for studying water relations in food are also discussed, including the polymer science approach and water mobility by magnetic resonance. Concepts in the practical uses and applications of water activity for food formulations, processing, and storage are illustrated with practical examples from the food industry that facilitates later applications in a variety of scenarios such as research laboratories and production facilities.

This book is a must for food science professionals for use in product development, quality control, and food safety. Food science students, engineers, and industry professionals alike will find in this book a relevant source for fundamentals as well as practical and informative work that makes understanding this core aspect of food manufacturing an engaging and accessible process.