Twelve years have passed since the first edition of this book. These twelve years have been rich in research which has brought about new techniques in the drying and dehydration of foods, and the creation of new products. It was therefore deemed advisable to bring the present book up to date in keeping with the latest technological advances.

It is not intended to present here an exhaustive treatise of the science of food dehydration, but rather to offer an integrated survey which it is hoped will be useful to chemical engineers and food processors. The book has been provided with footnotes and references so that the reader may consult pertinent research papers for further details. In this connection, the author again expresses his appreciation to those research workers from whose papers he has taken liberty of presenting data, and to those companies and individuals who have kindly lent illustrations. Every effort has been made to indicate the source of such information.

The final story of food dehydration has not yet been written, and this field continues to present a challenge to the chemist and chemical engineer.