Nitrite Curing of Meat: The N-Nitrosamine Problem and Nitrite Alternatives

280 Pages·2004·12.7 MB·English

by  Ronald B. Pegg

NITRITE CURING OF MEAT
The N-Nitrosamine Problem and
Nitrite Alternatives
RONALD B. PEGG, Ph.D.
Saskatchewan Food Product Innovation Program
Department of Applied Microbiology and Food Science
University of Saskatchewan, Saskatoon, SK, S7N 5A8
Canada
and
FEREIDOON SHAHIDI, Ph.D.
FACS, FCIC, FCIFST, FRSC
University Research Professor
Department of Biochemistry
Memorial University of Newfoundland
St. John's, NF, A1B 3x9
Canada
FOOD & NUTRITION PRESS, INC.
TRUMBULL, CONNEXTICUT 06611 USA

NITRITE CURING OF MEAT
The N-Nitrosamine Problem and
Nitrite Alternatives
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NITRITE CURING OF MEAT: N-NITROSAMINE PROBLEM, R.B. Pegg & F. Shahidi
DICTIONARY OF FLAVORS, D.A. DeRovira
FOOD SAFETY: THE IMPLICATIONS OF CHANGE, J.J. Sheridan et al.
FOOD FOR HEALTH IN THE PACIFIC RIM, J.R. Whitaker et al.
DAIRY FOODS SAFETY: 1995-1996, A COMPENDIUM, E.H. Marth
OLIVE OIL, SECOND EDITION, A.K. Kiritsakis
MULTIVARIATE DATA ANALYSIS, G.B. Dijksterhuis
NUTRACEUTICALS: DESIGNER FOODS 111. P.A. Lachance
DESCRIPTIVE SENSORY ANALYSIS IN PRACTICE, M.C. Gacula, Jr.
APPETITE FOR LIFE: AN AUTOBIOGRAPHY, S.A. Goldblith
HACCP: MICROBIOLOGICAL SAFETY OF MEAT, J.J. Sheridan et al.
OF MICROBES AND MOLECULES: FOOD TECHNOLOGY AT M.I.T., S.A. Goldblith
MEAT PRESERVATION, R.G. Cassens
S.C. PRESCOTT, PIONEER FOOD TECHNOLOGIST, S.A. Goldblith
FOOD CONCEPTS AND PRODUCTS: JUST-IN-TIME DEVELOPMENT, H .R. Moskowitz
MICROWAVE FOODS: NEW PRODUCT DEVELOPMENT, R.V. Decareau
DESIGN AND ANALYSIS OF SENSORY OPTIMIZATION, M.C. Gacula, Jr.
NUTRIENT ADDITIONS TO FOOD, J .C. Bauernfeind and P.A. Lachance
NITRITE-CURED MEAT, R.G. Cassens
POTENTIAL FOR NUTRITIONAL MODULATION OF AGING, D.K. Ingram et al.
CONTROLLED/MODIFIED ATMOSPHERE/VACUUM PACKAGING, A. L. Brody
NUTRITIONAL STATUS ASSESSMENT OF THE INDIVIDUAL, G.E. Livingston
QUALITY ASSURANCE OF FOODS, J.E. Stauffer
SCIENCE OF MEAT & MEAT PRODUCTS, 3RD ED., J.F. Price and B.S. Schweigert
ROLE OF CHEMISTRY IN PROCESSED FOODS, O.R. Fennema et al.
NEW DIRECTIONS FOR PRODUCT TESTING OF FOODS, H.R. Moskowitz
PRODUCT DEVELOPMENT & DIETARY GUIDELINES, G.E. Livingston. et al.
SHELF-LIFE DATING OF FOODS, T.P. Labuza
ANTINUTRIENTS AND NATURAL TOXICANTS IN FOOD, R.L. Ory
POSTHARVEST BIOLOGY AND BIOTECHNOLOGY, H.O. Hultin and M. Milner
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JOURNAL OF MUSCLE FOODS, N.G. Marriott and G.J. Flick, Jr.
JOURNAL OF SENSORY STUDIES, M.C. Gacula, Jr.
FOODSERVICE RESEARCH INTERNATIONAL, C.A. Sawyer
JOURNAL OF FOOD BIOCHEMISTRY, N.F. Haard, H. Swaisgood and B.K. Simpson
JOURNAL OF FOOD PROCESS ENGINEERING, D.R. Heldman and R.P. Singh
JOURNAL OF FOOD PROCESSING AND PRESERVATION, D.B. Lund
JOURNAL OF FOOD QUALITY, J.1. Powers
JOURNAL OF FOOD SAFETY, T.J. Montville and D.G. Hoover
JOURNAL OF TEXTURE STUDIES, M.C. Bourne and T. van Vliet
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FOOD, NUTRACEUTICALS AND NUTRITION, P.A. Lachance and M.C. Fisher
NITRITE CURING OF MEAT
The N-Nitrosamine Problem and
Nitrite Alternatives
RONALD B. PEGG, Ph.D.
Saskatchewan Food Product Innovation Program
Department of Applied Microbiology and Food Science
University of Saskatchewan, Saskatoon, SK, S7N 5A8
Canada
and
FEREIDOON SHAHIDI, Ph.D.
FACS, FCIC, FCIFST, FRSC
University Research Professor
Department of Biochemistry
Memorial University of Newfoundland
St. John's, NF, A1B 3x9
Canada
FOOD & NUTRITION PRESS, INC.
TRUMBULL, CONNEXTICUT 06611 USA
Copyright 2000 by
@
FOOD & NUTRITION PRESS, INC.
6527 Main Street
Trumbull, Connecticut 0661I USA
All rights reserved. No part of this publication may
be reproduced, stored in a retrieval system or
transmitted in any form or by any means:
electronic, electrostatic, magnetic tape, mechanical,
photocopying, recording or otherwise, without
permission in writing from the publisher.
Library of Congress Catalog Number: 00 132300
ISBN: 0-917 678-50-8
Front cover photo courtesy of the Saskatchewan
Food Product Innovation Program, Research &
Development for the Meat Industry, Department of
Applied Microbiology and Food Science, University
of Saskatchewan, 5 1 Campus Drive, Saskatoon,
SK, S7N 5A8, Canada.
Printod in tho Tlnitod Ctntor /If Amorirn
PREFACE
Meat has been treated for centuries with rock salt as a means of preserva-
tion. However, only one century has passed since the German researchers,
Polenske in 1891, Kisskalt in 1899 and Lehmann in 1899 discovered that the
active component in the curing process was nitrite. It is interesting to look back
over this century to see what actually transpired in a hundred years. How much
more do we really know about nitrite, its chemistry and its preservative effect
on meat than we did a century ago? What were the milestones achieved, if any?
Have we learned things about nitrite that perhaps we didn’t want to know, and
has technical advancement in terms of processing by meat packers resulted in
the loss of certain traditional old-world meat products?
In the beginning, the role of nitrite as a meat curing agent was revealed and
shortly thereafter, government regulators placed guidelines on the level of nitrite
and nitrate permitted for use in cured meat formulations. The importance of salt
in combination with nitrite as an antibotulinal agent and the limited understand-
ing of its mode of action was a key event during this century. In the late 1960s
and early 1970s, the development of the so-called “nitrite problem” surfaced on
account ofthe detection of N-nitrosamines in processed meats. The industry was
in an uproar, and the issue rose to the very pinnacle of interest, for both the
public and research scientist. A major technical advance in the analytical
technique for N-nitrosamine detection was achieved when Thermo Electron of
Waltham, Massachusetts introduced the thermal energy analyzer (TEA). This
unit was a watershed in N-nitrosamine research because it became possible to
screen a large number of samples with only a minimum preparation. As an
analytical tool, the selectivity ofthe instrument for detecting sub pg/kg quantities
of N-nitroso compounds in complex biological materials and foodstuffs without
the elaborate clean-up procedures was far beyond anything else available. Today
the TEA is recognized as a cornerstone for analytical N-nitrosamine detection.
In terms of nitrite chemistry, the controversy over the identity of the pigment
of thermally processed nitrite-cured meat raged on for decades. Early studies
suggested that the pigment of cooked cured-meat was a dinitrosyl protoheme
complex. Yet, a number of scientists were able to unravel some of the earlier
conclusions presented in the scientific literature and provide compelling evidence
to support their hypothesis that the pigment of nitrite-cured meat was indeed a
mononitrosyl ferrohemochrome. The role of nitrite in revealing the desired and
unique flavor of cured products, perhaps by suppressing the formation of lipid
oxidation products, was another development in revealing other properties of
nitrite. Above all, the antimicrobial role of nitrite, together with salt, had a
major influence on the popularity of nitritehitrate in food preservation.
V
vi PREFACE
This book presents a review of the desirable attributes that sodium nitrite
confers to meat during processing, as well as drawbacks of nitrite usage, i.e.,
the presence of N-nitroso compounds, particularly N-nitrosamines. Furthermore,
the book provides solutions with regard to curing of meat without the use of
nitrite. An examination of a multicomponent nitrite-free curing system entailing
the color, tlavor, and microbial protection of such a system is presented in
Chapter 9. The book has been divided into the following chapters.
Chapter 1 begins with a general introduction of what cured meats are,
followed by an overview of the main benefits and drawbacks nitrite affords meat
and meat products.
Chapter 2 contains a review of the history of the curing process. Issues on
how curing began, techniques used then and today, and the discovery of nitrite
as the active agent are addressed. This chapter will also introduce the character-
istic attributes which nitrite affords meat and will lay the foundation for the
remainder of the book.
Chapter 3 deals with the color characteristics of meat and meat products
with particular emphasis placed on the chemistry of muscle pigments. The color
of fresh meats, how nitrite modifies it and the color of the product after thermal
processing will be described. A review of the controversy surrounding the exact
chemical structure of the cooked cured-meat pigment is reported, as well as
evidence which supports the view that the cooked cured-meat pigment is a
mononitrosylheme complex.
Chapter 4 begins with a brief introduction on what is meant by the oxidative
stability of meat lipids and further details how lipid oxidation in uncured frozen
and cooked meat proceeds. Nitrite’s role in curbing meat flavor deterioration
(MFD), previously referred to as warmed-over flavor (WOF), and the proposed
mechanism(s) of nitrite’s antioxidative efficacy are addressed. A review of the
classical 2-thiobarbituric acid (TBA) test, used for assessing the extent of lipid
oxidation in meats, follows. The difficulties raised by nitrite in the TBA test is
accounted, and an alternative approach for assessing the oxidative status of cured
meat systems is furnished.
Chapter 5 deals with the flavor of uncured cooked meat and places
particular emphasis on the volatile flavor compounds mainly responsible. The
relationship between nitrite and cured-meat flavor is explored and the chapter
concludes with a simplistic view on how the basic flavor of cooked meat,
species differentiation and MFD may be interrelated.
Chapter 6 discusses the microbial status of cooked meat with concerns over
possible contamination by Clostridium botulinum spores. A general review of the
microbiology of Closfridium botulinum, with regard to how it proliferates and
how nitrite exerts a concentration-dependent antimicrobial action in combination
with added sodium chloride and adjuncts is recounted. A more detailed review
of the bacteriostatic properties of nitrite follows.
PREFACE vii
Chapter 7 explores the fate of nitrite in the meat matrix. The reactive nitrite
anion exists in various forms in meat; it may be converted to nitrogen gas,
nitrate, nitrous acid, its anhydride dinitrogen trioxide, or it may react with
heme-based muscle pigments, protein, lipid and sulfhydryl-containing com-
pounds in the meat matrix.
Chapter 8 deals with the potential hazards of nitrite usage in meat. A review
of the N-nitrosamine story is reported and covers how N-nitrosamines are
formed, and their prevalence in various nitrite-cured meat and meat products.
A discussion on current meat industry regulations for nitrite usage, which
includes why nitrite usage in fish is banned, as well as various means to prevent
and retard N-nitrosamine formation, follows. This chapter also includes
N-nitrosamine inhibitors which are available to the meat processor, and the
impact of a nitrite-ban to the industry.
Finally, Chapter 9 considers possible substitutes for nitrite with regard to
the use of a multicomponent nitrite-free curing system. This chapter considers
color characteristics, antioxidant properties, flavor characteristics and antimicro-
bial choices for nitrite alternatives. The section on color attributes of nitrite-free
meats deals with various food-grade dyes and pigments available for addition to
meat with a review of their advantages and limitations. A discussion of why the
cooked cured-meat pigment itself, performed outside of the meat matrix, is the
only appropriate alternative for nitrite-free curing of meat is described in detail.
The section on antioxidant properties deals with synthetic and natural antioxi-
dants available for use in meat to mimic the effect of nitrite. A discussion on
these antioxidants, as well as chelators and synergism noted between combina-
tions is reported. The section on flavor characteristics of nitrite-free meat
considers sensory studies already performed on such systems, as well as the role
of salt and smoking to the flavor. The last section in this chapter reviews the
various food-grade antimicrobial agents available for use in nitrite-free curing
of meat and evaluates those which have been tested, those which are promising,
and those which are not. A concluding section on the multicomponent nitrite-free
curing package and its usefulness to the industry is provided.
The book thus presents a state-of-the-art account of nitrite, the N-nitrosa-
mine problem and nitrite-free meat curing alternatives which would be of
interest to meat scientists, government regulators and the industry. Food
scientists, nutritionists and biochemists would also find this book informative and
useful for inclusion as materials to be covered in a graduate meat science or
food chemistry course.
RONALD B. PEGG
FEREIDOON SHAHIDI