Über die Autorin bzw. den Autor

RICHARD H. STADLER, PHD, is the head of the Quality Management Department at the Nestlé Product Technology Center in Orbe, Switzerland.

DAVID R. LINEBACK, PHD, is the Director (Retired) of the Joint Institute for Food Safety and Applied Nutrition (JIFSAN) at the University of Maryland.

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A COMPREHENSIVE LOOK AT ANALYTICAL, HEALTH, AND RISK MANAGEMENT ISSUES

Process-Induced Food Toxicants provides a much-needed single-source reference on food process toxicants that also answers important food safety questions. The text presents currently known toxicants, and includes a balanced view, given by renowned experts in industry, academia, and the regulatory field, of mitigation options, risk assessment, and risk management for these compounds.

The text begins by considering different processes used in the manufacture and processing of foods including thermal treatment, drying, fermentation, preservation, and high hydrostatic pressure processing and examines the risks of potential contaminant/toxicant formation as they relate to each processing method. For each subject covered, the book offers a consistent approach featuring:

• Occurrence in food
• Methods of analysis
• Mechanisms of formation
• Approaches to mitigation/reduction
• Human exposure through the food supply
• Potential health risks
• Risk management

Process-Induced Food Toxicants gives readers the latest information based on results from recent research, as well as new technological and methodological developments and how they bear on mitigation. These include both analytical methodologies and practical systems such as HACCP for managing food safety concerns. Process-Induced Food Toxicants provides a wide range of students and professionals in food science, food technology, toxicology, public health, public policy, and other related disciplines with a unique, comprehensive, and invaluable resource.

Aus dem Klappentext

A COMPREHENSIVE LOOK AT ANALYTICAL, HEALTH, AND RISK MANAGEMENT ISSUES

Process-Induced Food Toxicants provides a much-needed single-source reference on food process toxicants that also answers important food safety questions. The text presents currently known toxicants, and includes a balanced view, given by renowned experts in industry, academia, and the regulatory field, of mitigation options, risk assessment, and risk management for these compounds.

The text begins by considering different processes used in the manufacture and processing of foods—including thermal treatment, drying, fermentation, preservation, and high hydrostatic pressure processing—and examines the risks of potential contaminant/toxicant formation as they relate to each processing method. For each subject covered, the book offers a consistent approach featuring:

• Occurrence in food
• Methods of analysis
• Mechanisms of formation
• Approaches to mitigation/reduction
• Human exposure through the food supply
• Potential health risks
• Risk management

Process-Induced Food Toxicants gives readers the latest information based on results from recent research, as well as new technological and methodological developments and how they bear on mitigation. These include both analytical methodologies and practical systems such as HACCP for managing food safety concerns. Process-Induced Food Toxicants provides a wide range of students and professionals in food science, food technology, toxicology, public health, public policy, and other related disciplines with a unique, comprehensive, and invaluable resource.

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Process-Induced Food Toxicants

John Wiley & Sons

Chapter One

David R. Lineback and Richard H. Stadler

1.1 HISTORY AND ROLE OF FOOD PROCESSING

Food processing and preservation, the traditional focus of food science and technology, have played, and continue to play, important roles in achieving food sufficiency (availability, quality, and preservation) for the human race. These practices originated in recognition of a need to improve the edibility of many food sources and to maintain food supplies for longer periods of time than their seasonal availability. With the transition from a hunter-gatherer society to life in villages and early agriculture, this need became even greater and emphasis on food preservation became increasingly important. This, of course, was paralleled by the development of processes/processing of animal, vegetable, and marine raw materials into usually more palatable, portable, and nutritionally dense foods. In many cases, if not most, this occurred in a fortuitous, rather than planned, manner as natural causes of food processing and preservation were observed and adapted to human use.

Food processing involves the actions taken from the time a raw product (crop, animal, fish) is harvested, slaughtered, or caught until it is sold to the consumer. By this process, the parts regarded as most valued are separated from by-products or waste. Equally enhanced is the palatability/digestibility of foods, illustrated in the transformation of baking flour into bread, to maintain or increase quality attributes and to ensure safety. Increasing understanding of the science involved in food loss, deterioration of quality, and means of improving the palatability of foods has resulted in development of the sophisticated methods of food processing and preservation now in use. The work of Pasteur, resulting in identification of the role of microorganisms in food spoilage and development of technology leading to canning by Nicolas Appert in 1809, can be considered initial steps in the development of modern food processing and preservation. As the world population continues to grow, resulting in increasing requirements and demands for food availability and safety, new and improved methods of food processing and preservation are needed and in development.

The term "minimal processing" is frequently used to describe foods, such as vegetables, that are harvested, sorted, and washed (or similar minimal invasive procedures) before distribution and sale. This is done to distinguish these more "natural" products from those that undergo more extensive processing procedures. Over the last years the development and distribution of minimally processed foods has been increasing steadily. This trend has been triggered by the demand for fresh and convenient products as well as for more natural products, i.e., less processed or containing less salt, sugar, or preservatives.

Such foods range from fruits and vegetables, which are usually only submitted to washing (with or without biocides), trimming, slicing, or shredding, to prepared foods processed by applying minimal bactericidal treatments in combination with different physicochemical hurdles to ensure their stability and safety. These foods represent certainly a challenge to manufacturers since no or only minimal killing steps are applied, and, at the same time, requirements for more global availability and longer shelf life are increasing. The fact that these challenges are frequently underestimated or not mastered sufficiently is illustrated by the occurrence of numerous incidents linked to a variety of products involving different pathogens. Outbreaks related to minimally processed foods often encompass chilled foods such as sous-vide products, pasteurized vegetables, and baked potatoes, which have frequently been linked to Clostridium botulinum intoxication.

Early types of processing/preservation evolved from observations of natural processes, e.g., drying, curing (such as salting), smoking, fermentation, and reducing storage temperature (refrigeration or freezing). Salting and smoke processing originated at the beginning of human civilization, mainly employed to preserve meat and fish. In fact, salting, pickling, and drying continued as the primary means of preserving foods until the twentieth century and the advent of mechanical refrigeration. More modern means of preservation precluded the use of copious amounts of salt, exemplified by the far reduced concentrations of salt in ham today (<2%) versus that in hams produced in the first half of the twentieth century (>6%). Changes to technologies were also introduced a few decades ago with regard to cured meats and residual nitrite content. Nitrite, used to cure meat, acts as a preservative against Clostridium botulinum and other spoilage bacteria. However, during the 1970s, concern arose due to the role of nitrites in the formation of carcinogenic nitrosamines (Chapter 4.1), as well as its contribution to the body burden. In modern cured meats, the nitrite amounts have decreased and are typically one-fifth of those found some 30 years ago. Moreover, the use of ascorbate-an effective inhibitor of nitrosamine formation-is an additional mitigation measure introduced in the production of most cured meats.

Smoke processing is still used today to preserve meat, especially in tropical countries. Smoke imparts appealing organoleptic properties, with concomitant preservation of nutrients. However, concern has been raised about the presence of both polycyclic aromatic hydrocarbons (PAHs) and nitrosamines in smoked foods. PAHs are covered in Chapter 2.8, with special attention to their formation, mitigation, and toxicology. Although the exposure risks in modern manufacture of meats and fish are considered minimal, alternatives to traditional smoking have been developed. Liquid smoke flavorings have gained popularity as they provide the same traits, i.e., desirable organoleptic properties, and preservation through antioxidation and bacteriostasis. Additional benefits include increased product consistency and absence of detectable animal carcinogens. In fact, approximately 75% of hot dogs produced in the United States contain aqueous liquid smoke flavorings.

Food preservation can be considered part of or an extension of food processing, since it involves the use of procedures to prevent or reduce spoilage of foods. Examples include the inactivation of enzymes and microorganisms by heating or reduction of moisture content, use of antimicrobial compounds, pasteurization (heat or irradiation), freezing, modified atmospheric packaging, and fermentation.

Techniques that have been used in food processing and preservation include:

Drying/dehydration

Curing

Smoking

Fermentation

Canning

Pasteurization (heat or irradiation)

Freezing and refrigeration

Additives

Controlled atmosphere storage

Aseptic packaging

Until the last quarter of the twentieth century, canning was widely used in homes throughout the rural United States. Inadequate heat treatment during the canning process occasionally resulted in severe illness or death caused by Clostridium botulinum that was not inactivated during the heating process and resulted in subsequent formation of the toxin....