Microbiologia en alimentos

Third Edition

FUNDAMENTAL FOOD MICROBIOLOGY
Bibek Ray

CRC PR E S S
Boca Raton London New York Washington, D.C.

This edition published in the Taylor & Francis e-Library, 2005. “To purchase your own copy of this or any of Taylor & Francis or Routledge’s collection of thousands of eBooks please go to www.eBookstore.tandf.co.uk.” Cover Image: Microscope with easy phase contrast, darkfield, and bright light facilities (M 4002 D). (Courtesy of Swift Instrument International, S.A.)

Library of Congress Cataloging-in-Publication Data
Ray, Bibek Fundamental food microbiology / Bibek Ray. --3rd ed. p. cm. Includes bibliographical references and index. ISBN 0-8493-1610-3 1. Food--Microbiology. I. Title QR115.R39 2003 664 .001 579--dc22

2003055738

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Dedication
To my parents, Hem and Kiron, and my family

Preface to the Third Edition
In the third edition, substantial changes have been made in most of the chapters and in their logical arrangement. Inaddition, one new chapter has been added. The chapter on microbial stress has been written to include various manifestations of bacteria under stress and their importance in food microbiology. As before, this book is written primarily for students taking undergraduate food microbiology courses. However, it can be used as a reference in other related courses in many disciplines as well as byprofessionals engaged directly and indirectly in food-related areas. I thank Elizabeth Smith for her excellent typing and editing in the preparation of the manuscript. Finally, I thank my students for their helpful suggestions, especially for the new materials included in this edition.

Preface to the First Edition
Between the time I first studied food microbiology as an undergraduate student andnow, the discipline has undergone a radical change. This change is well expressed by Dr. David Mossel of the Netherlands in his letter published in ASM News (59, 493, 1993): from “no challenge in plate count and coliform scouting” to “linkage of molecular biology to food safety (also food bioprocessing and food stability) strategies — proclaim a new era in food microbiology.” This transition wasnecessary to meet the changes that occurred in the food industry, especially in the U.S. and other developed countries. The necessary knowledge, techniques, and expertise for this transition were available. This book reflects this transition from the traditional approach to an approach to meet the needs of those who are directly or indirectly interested in food microbiology. Introductory food...