Toxins and Other Harmful Compounds in Foods

A. Witczak, Zdzislaw Sikorski

• Publisher: CRC Press
• Year: 2017
• ISBN:
  9781315351513
• Edition: 1
• Topic: Medicine
• Subtopic: Toxicology

Toxins and Other Harmful Compounds in Foods provides information on the contents, distribution, chemical properties, and biological activity of toxins and other harmful compounds in foods that are natural components of the raw materials, accumulated due to microbial actions and environmental pollution, or are generated due to processing. This book shows how different factors related to the production of raw materials, as well as to storage and processing conditions, affect the presence and concentration of toxins and other harmful compounds in foods. It shows how various regulations, as well as unit operations and processes used in food production, may eliminate different toxins or generate new ones. The real health hazards for the consumers resulting from the presence of toxic/harmful compounds in aliments are discussed, and various national and international regulations obligatory in agriculture and industry aimed at increasing food safety are presented. Methods of analysis used for detection and determination of undesirable compounds are also discussed, making it possible to understand the effect of storage and processing parameters, as well as systems of quality assurance, on food safety and to select optimum procedures for analytical control.

1 Problems of Food Safety

Waldemar Dąbrowski and Agata Witczak

CONTENTS

1.1 Introduction

1.2 Changes in Food Production and Nutrition

1.3 The Globalization of Food Production

1.4 Changes in Public Health and Dietary Habits

1.5 Xenobiotics in the Environment and Food

1.6 Conclusions

References

1.1 INTRODUCTION

Knowledgeable consumers expect not only high sensory quality of food, but also need the elimination of risks from frequently dangerous microbial, biological, and chemical contamination. Microbial contamination results from negligence during the transport, storage, and production stages, as well as from genetic variability and metabolic flexibility of micro-organisms. An example of such flexibility is the bacterium Escherichia coli. These micro-organisms were characterized many years ago as human and animal commensals or pathogens. They were categorized into 6 groups and 190 serotypes. In 2011, a new strain of E. coli occurred in Germany—a highly pathogenic, enteroaggregative strain of serotype O104:H4 that caused an outbreak involving 3842 cases of human infections, including 51 deaths. The disease resulted from the consumption of contaminated sprouted fenugreek seeds (Beutin and Martin 2012). More than 800 people infected had symptoms of hemolytic uremic syndrome, which may lead to loss of kidney functions. Apart from Germans, there were also residents of other countries, especially France, Denmark, and Sweden, among the infected people. The contaminated seeds were probably imported from Egypt. The major causes of the outbreak were globalization of raw materials, lack of adequate hygienic standards in mass production, and international migrations of people.

Chemical contamination may also result from negligence during production, but its major cause is the widespread chemicalization of the natural and human environment. Improvements in analytical and diagnostic methods, including meta-analysis, cohort studies, and randomization, enable detection of previously unknown hazards and causes of human health disorders. Improved analytical methods, including the introduction of high-performance gas and liquid chromatography, in particular coupled with mass spectrometry, enable detection of compounds that were undetectable by conventional analytical methods. For example, some foods regarded as strongly healthy have been found to contain hazardous compounds such as 3-monochloropropane-1,2-diol in soya sauces or carbamates in pickled products.

Today most hazardous chemicals penetrate human organisms via the alimentary tract, and inadequate nutrition is regarded among the major pathogenic factors.

1.2 CHANGES IN FOOD PRODUCTION AND NUTRITION

Changes in food production involve the following:

• Concentration of production in factories of increasing processing efficiency
• Changed production methods
• Increased number and more types of products
• Increased number and more types of unconventional foods (from other regions of the world)

Increased production efficiency in a food-processing factory contributes to increased production, which significantly increases the number of consumers, and thus enlarges the risk from any production negligence. The consolidation of dairy plants in Poland (creamery and cheese-making industry) may be cited as an example. Currently, there are nearly 250,000 consumers to one creamery.

Changes in production methods concern various aspects, for example, changed sterilization methodology, where technologies of high-pressure, high-voltage electric impulses, or light impulses are introduced instead of thermal sterilization. Another example of threat associated with changes in production methods is hydroponic production of sprouts. In 1996, 6,000 children from Sakai, Japan, got infected after eating radish sprouts contaminated by enterohemorrhagic E. coli of 0157:H7 serotype. A similar big outbreak triggered by sprouts contaminated by E. coli 0104:H4 occurred in Germany in 2011. According to Meathead Goldwyn, “raw sprouts may be the riskiest food in the world” (http://amazingribs.com/blog/raw_sprout_are_risky.html).

Ready-to-eat food products are growing in number and variety. Such foods usually require heating before serving. In the case of dumplings, the most appropriate procedure is processing in boiling water. Consumers, however, usually prefer microwave heating, which does not fully prevent the risk of infection with some kinds of pathogens (Szymczak and Dąbrowski 2015).

On the market, there are more and more food products from all over the world. Surimi crabsticks or Japanese sushi have become quite widespread. Their production on Asiatic markets is usually combined with centuries-long tradition. However, starting their mass production in distant countries may be hazardous. Recently in Europe, a red rice appeared, also called “red koji,” “red Chinese rice,” or “red mold rice.” This rice has been produced in China for centuries, with the use of molds Monascus purpureus. As early as in the fifteenth century, Chinese pharmacopeia described health-promoting properties of this rice, as it regulates consumers’ lipid metabolism due to the presence of monacolin—a precursor of statins. However, some Monascus strains produce citrinin, an extremely harmful hepatonephrotoxin, which may produce dramatic health effects in consumers when the control of import is inadequate.

1.3 THE GLOBALIZATION OF FOOD PRODUCTION

Globalization is a process of changes in societies and economies, leading to an increasing interrelationship and integration of countries, societies, economies, and cultures. This integration applies to economic issues in particular. In Europe, it was initiated by establishing the European Free Trade Association (EFTA) in 1960. A free trade area among EFTA member states was formed in 1968. In 1992, the European Economic Community (EEC) and EFTA reached an agreement and formed a common free trade area for all goods. This agreement entered into force on January 1, 1994, and established the European Economic Area. In 1980, the United Nations Convention on Contracts for the International Sale of Goods (CISG) was signed in Vienna, which is a multilateral international treaty on the rules of international sale of goods. Until 2010, the convention had been ratified by 77 states. These agreements promote, among others, international food trade, which is also facilitated by opened boarders in the European Union (EU), the Customs Union abolishing customs duties within the EU, and the rapid development of road, sea, and air transport. All this strongly influences the development of the food industry and related food safety, as well as increasingly complex cross-border flows of raw materials and finished products (Hawkes 2006). Areas previously free from some hazards are currently exposed to the import of foods, often from different climate zones, contaminated by unknown types of micro-organisms. This poses an additional risk, especially for children, for example, due to the occurrence of viral diarrhea of unknown origin. Closer attention is also paid to adequate conditions of transportation and storage, especially considering the long logistic chains. A classic example of improper production and transportation was the case when in 1960 more than 100,000 turkeys on poultry farms in England died as a result of intoxication by feed contaminated by an aflatoxin from imported peanuts.

1.4 CHANGES IN PUBLIC HEALTH AND DIETARY HABITS

Health condition of a society is proportional to its wealth. The wealthier a society is, the more valued is human health and life (http://www.who.int/health-accounts/ghed/en/). These theses can be based not only on data on the expenditures of individual countries on disease prevention and treatment, but also on the comparison of infant mortality and average life expectancy. This stimulates medicine development and contributes to continuous introduction of new drugs. The effects are not only positive, but also negative. Among negative ones, there is suppressed immunity in patients due to frequent use of anticancer and immunosuppressive drugs. These medicines are widely used in therapies against cancer, autoimmune diseases, and allergies, as well as in patients after an organ transplant. As a result of the pharmacotherapy, there are an increasing number of people with suppressed immunity, for which an infection with even trivial micro-organisms may be life threatening. Therefore, even micro-organisms of low pathogenicity, when present in food, may pose a health risk. Moreover, the progress of civilization increases the number of allergic people. Previously, natural selection eliminated a large part of the population with this genetic predisposition. Asthmatic children usually died as a result of secondary pneumonia. Currently, they reach the reproductive age, and for both parents with allergies, the likelihood of having an allergic child increases by 20%–30%. Food allergies affect 4%–6% of children and 2%–3% of adults (Sicherer and Samson 2014). For these people, even trace amounts of allergens in food can be of dramatic consequences. The fact has been imposing increasingly rigorous “allergic hygiene” standards upon food manufacturers, so that finally a food allergy hazard analysis and critical control points (HACCP) system has been developed.

Increased risk for human health from food consumption is also associated with changing life styles, consumption patterns, and dietary habits. We live faster and differently. Many people eat out, which is a consequence of working time duration, and sometimes also of travel-to-work time. At home, a large number of families have made drastic changes in their dietary habits. Excessive amounts of crisps, chips, and other junk foods and beverages excessively sweetened with glucose–fructose syrup are consumed. As a result, a massive increase in obesity has occurred among the people of developed countries, followed by an increase in diabetes and cardiovascular diseases. Certain foods, for example, harden vegetable fats containing trans-fatty acids, which are formed during the partial hydrogenation of vegetable oils. Transfats double the risk of breast cancer and increase the level of bad cholesterol, low-density lipoprotein (LDL), which translates into an increased risk of atherosclerotic diseases. Denmark and Canada, in an attempt to solve this problem, require food manufacturers to report data on trans-fat content in their products on product labels and to reduce the content.

1.5 XENOBIOTICS IN THE ENVIRONMENT AND FOOD

Food safety should be a guarantee that no adverse effects occur in the human body after food ingestion. Over the centuries, humans have learned to avoid certain plant and animal species—recognized as inedible or even poisonous (Wilcock et al. 2004). Potential contaminants in foodstuff may be of a natural origin (e.g., bacterial and fungal toxins, amygdalin, and solanine) or may be absorbed from the polluted environment (e.g., nitrates (V), nitrates (III), heavy metals—lead, cadmium, mercury, residues of fertilizers and pesticides, dioxins, phthalates, and residues of veterinary drugs). Contaminants that accumulate in the organisms are considered as the most dangerous. A wide use of antibiotics in animal husbandry also became a serious problem, as it contributed to the transfer of antibiotic resistance from animals to humans. Significant sources of food contamination also include substances formed during technological processing and storage. This group consists of mycotoxins, nitrosamines, acrolein, epoxides, and other compounds.

Another group of food contaminants consists of foreign substances introduced to food products during technological processing. The group includes cleaning agents, preservatives, sweeteners, dyers, and chemical contaminants passing to food from the packaging and equipment.

A majority of chemical contaminants detected in foods are difficult or even impossible to avoid. These include certain metals, nitrates, N–nitroso compounds, pesticides, dioxins, dibenzofurans, PAHs, and other polyhalogenated polycyclic aromatic compounds. An important group is constituted by halogenated aromatic hydrocarbons, classified as persistent organic pollutants (POPs).

Some of the substances mentioned earlier (pesticide residues, dioxins, polychlorinated biphenyls, and other POPs) have been detected for many years in both aquatic and terrestrial environment worldwide, which is reflected in their constant, although gradually decreasing, presence in food.

1.6 CONCLUSIONS

Food safety, according to the Food and Agriculture Organization, is an important component of food security, that is, physical and economical access to food for each resident. Ensuring food safety is closely related to minimizing the risk of any side effects in the human body.

Food safety is an area of increasing global interest because of its direct impact on human health. Safe food is food that comes from a clean, unpolluted natural environment. Since 1960s, health hazards have been regarded not only in terms of microbiological, but also chemical food contamination. Currently, health quality and safety of food are among the most important criteria for consumers’ assessment of food. For this reason, food quality assessment covers not only functional, sensory, esthetic, and hygienic aspects, but also the content of foreign chemicals (xenobiotics) in the product that may endanger human safety.

As shown in numerous studies, incorrect culinary or technological processing or improper storage may result in the formation of toxic compounds in foods, including acrolein, nitrosamines, and mycotoxins.

The most dangerous risks associated with the majority of xenobiotics are their carcinogenicity, teratogenicity, and endocrine-disrupting activity.

Among numerous chemical hazardous to hum...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Series Preface
• Preface
• Editors
• Contributors
• Chapter 1 Problems of Food Safety
• Chapter 2 Natural Toxins of Plant Origin (Phytotoxins)
• Chapter 3 Mushroom Toxins
• Chapter 4 Marine Phycotoxins and Seafood Safety
• Chapter 5 Biogenic Amines
• Chapter 6 Mycotoxins
• Chapter 7 Bacterial Toxins
• Chapter 8 Pesticide, Fertilizer, and Antibiotic Residues in Food
• Chapter 9 Toxic Microelements in Food
• Chapter 10 Cyanogenic Compounds and Estrogen Disruptors
• Chapter 11 Phthalates
• Chapter 12 Dioxins and Dioxin-Like Compounds in Food
• Chapter 13 Epidemiological and Medical Impact of Food Contamination by Viruses Transmission via Food and Water
• Chapter 14 Possible Adverse Effects of Food Additives
• Chapter 15 Food Allergens
• Chapter 16 The Effect of Processing on the Safety and Nutritional Value of Food
• Chapter 17 Toxic Components of Food Packaging Materials
• Chapter 18 Detection of Harmful Compounds in Food
• Chapter 19 Regulations Established to Control Harmful Food Contaminations
• Index