Technical Talk: June 2012
May 29, 2012
By Dr. John Michaelides
Food safety is at the top of many minds today as more and more people want to know exactly where their food comes from.
Food safety is at the top of many minds today as more and more people want to know exactly where their food comes from. In today’s world, the public effectively becomes aware of products that pose a danger to their health via government information websites, the media and other means. The various recently reported food poisoning outbreaks have enhanced this awareness. Food security has also received elevated attention since the events of 9-11 because terrorism can spread through the food system.
|Biofilms can form on equipment surfaces when equipment is not cleaned and sanitized properly, harbouring pathogens that could contaminate food.
There are two aspects of food safety and security. One is the technical or scientific basis, which is the root cause of concerns relating to food safety and security. Two is the raft of programs that enable food manufacturers and handlers to protect food from contamination and reduce danger to the consumer.
The different hazards that can cause food safety and security problems are usually categorized as biological, chemical and physical. Biological hazards originate from living things, such as bacterial pathogens, viruses and parasites.
Bacterial pathogens cause food poisoning in two distinct ways. First, they can grow in the food when the conditions are right and produce toxins that will affect humans and other animals. For example, Clostridium botulinum produces spores which will survive the normal cooking temperatures of food. When the food cools these spores germinate and grow, producing a powerful neurotoxin that will cause food-borne illness and may result in death. In order to grow, Clostridium requires the absence of oxygen. While this is good for many food products, it poses a problem for foods that are packaged in modified atmospheres. Similarly Bacillus cereus, which is normally associated with cereals, produces spores and a less severe toxin also causing food poisoning. The physical symptoms associated with pathogens that produce toxins normally appear fairly quickly. Bacterial pathogens can also cause food poisoning in the form of an infection. This type of food poisoning involves many of the pathogens we are familiar with, including Salmonella, Listeria, Campylobacter, E. coli and others. The symptoms for such types of food poisoning appear much more slowly. They normally infect body tissues, where they produce toxins that affect various organs and can cause prolonged and, in some cases, chronic, illnesses. Some are particularly dangerous to different population groups. For example, Listeria monocytogenes has severe implications for the elderly, pregnant women, infants and immunocompromised individuals.
Pathogens from raw ingredients contaminate food because of insufficient heating, cross-contamination with handlers and equipment, or the processing environment itself. Biofilms can form on equipment surfaces when equipment is not cleaned and sanitized properly. These biofilms harbour pathogens that can contaminate food; some of which can be present in the processing environment such as wet floors, cracks and crevices, and drains. For example, Listeria monocytogenes is known to persist in such areas with the potential for cross-
contamination of finished food products.
Viruses are also another form of biological hazard and can easily contaminate food through handlers and pests. Pests are a major hazard because they can spread pathogens through processing facilities and contaminate raw ingredients, equipment and foods. Parasites can contaminate food through ingredients and water. For example, meat (such as pork) and fish may contain parasites that, if not adequately heat-treated, can survive and contaminate food.
Other hazardous substances of biological origin that can contaminate food include natural toxins, such as mycotoxins (from fungi) and shellfish toxins (due to accumulation of toxins from algae in shellfish). Aflatoxin is an example of mycotoxin, which is very serious and regulated in food products. Aflatoxin is produced by the fungus Aspergillus flavus. This toxin is normally found in nuts and cereals that are improperly stored under high humidity conditions.
Allergens are another hazardous food contamination that may pose severe health problems. These substances of plant or animal origin are normally proteins. An allergic reaction occurs when the immune system reacts to specific proteins present in the food. Reactions can be mild to very severe. The most common reaction is the production of antibodies to the food by the body. Severe reactions can cause anaphylactic shock that may result in death.
Chronic reactions to food include celiac disease, which involves the gluten protein found in wheat, barley and rye. Other allergens include milk, eggs, peanuts and tree nuts. Different countries have varying restrictions with regards to allergens. It is important to understand the difference between allergies and food intolerances. Food intolerances do not involve the immune system. For example, lactose intolerance occurs when a person lacks the enzymes required to digest milk sugar, resulting in gas, bloating and abdominal pain. The agents that cause BSE, or mad cow disease, are another form of contamination of food, resulting from unsafe animal feeding practices. These agents are very difficult to eliminate once they contaminate food.
Chemical hazards can be the result of unintentional contamination of foods with chemicals posing a health danger to consumers. The food production industry deals with many chemicals; starting from the field and storage, pesticides are used to control unwanted pests and can easily end up in food products. Many chemicals are also used as lubricants, cleaning and sanitizing agents that can contaminate food in processing facilities. It is important to segregate such chemicals in food processing facilities in order to minimize the incidents of food contamination. Preservatives and antimicrobial agents are also permitted in various food formulations,and the amount used in foods is regulated based on safety assessments. It is important that their application is accurate.
The third type of hazard in foods is contamination with agents, such as wood and glass, which can cause physical injury to consumers. Wood splinters from wooden pallets can easily end up in food products. Although more and more food manufacturers are switching to plastic, glass is still widely used due to its superiority in ensuring longer shelf life of certain products. Glass pieces from brakeage can end up in food, and glass is very difficult to detect in food products. Metal contamination from machinery or other sources also poses a hazard, but unlike glass, it is easy to locate in food products with the use of metal detectors.
The forms of contamination discussed are all unintentional. The intentional contamination of food is termed food tampering. Food tampering is very serious because it may take place beyond the control of the food manufacturer – it can be carried out by unhappy employees, consumers or terrorists.
In the next article we will discuss the various programs of food safety and security that help companies produce and deliver safe food to the consumers.
For more information, or fee-for-service help with food technical and
processing issues and needs, please contact Dr. John Michaelides at
John Michaelides & Associates at 519-743-8956, or at Bioenterprise
519-821-2960 ext. 226, or by e-mail at firstname.lastname@example.org.
Bioenterprise is a company of experienced professionals that coach and
mentor emerging agri-technology companies from planning to startup to
profitability and beyond.
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