Food Hazards and Contamination PDF

TH2203 FOOD HAZARDS Hazards and Contamination Contamination refers to the unintended presence of harmful organisms or substances in food (Labensk...

TH2203 FOOD HAZARDS Hazards and Contamination Contamination refers to the unintended presence of harmful organisms or substances in food (Labensky et al., 2018). Most foodborne illnesses are the result of eating contaminated food. Food is contaminated if it contains harmful substances not originally present in it. Any substance in food that can cause illness, injury, or harm is called a hazard (Gisslen, 2015). There are four (4) types of food hazards: biological hazards, chemical hazards, physical hazards, and allergens. A biological hazard is a danger to food safety caused by disease-causing microorganisms such as bacteria, molds, yeasts, viruses, or fungi. Chemical hazard is a danger to food safety caused by chemical substances, especially cleaning agents, pesticides, and toxic metals. Physical hazard refers to a danger to food safety caused by particles such as glass chips, metal shavings, bits of wood, or other foreign matter. An allergen is a substance that causes an allergic reaction. Contamination occurs in two (2) ways: direct contamination and cross-contamination. Direct contamination is the contamination of raw food items or the plants or animals from which they come, in their natural settings or habitats. Chemical and biological contaminants, such as bacteria and fungi, are present in the air, soil, and water. So, food items can be easily contaminated by their general exposure to the environment  grains can become contaminated by soil fumigants in the field, and shellfish can become contaminated by ingesting toxic marine algae (Labensky et al., 2018). Most food contamination occurs due to cross-contamination, or the transference of hazardous substances, mainly microorganisms, to food from another food or surface such as equipment, worktables, or hands. Examples of situations in which cross-contamination can occur are the following (Labensky et al., 2018): Mixing contaminated leftovers with a freshly cooked batch of food Handling ready-to-eat food with unclean hands Handling several types of food without washing hands in between Cutting raw chicken then using the same unsanitized cutting board to cut vegetables Placing ready-to-eat food on a lower refrigerator shelf and allowing juices from raw fish or meat to drip on it from an upper shelf Wiping down work surfaces with a soiled cloth Consumption of contaminated food causes foodborne illnesses. Foodborne illnesses refer to diseases, usually either infectious or toxic, caused by agents that enter the body through the ingestion/consumption of contaminated food (World Health Organization [WHO], 2022). Some of the common foodborne illnesses and their causes are shown in Table 1 (US Food and Drug Administration [FDA], 2019). Table 1 Common Foodborne illnesses Organism Name of Illness Sources Bacillus Cereus B. Cereus Food Poisoning Meats Campylobacter jejuni Campylobacteriosis Raw and undercooked poultry, unpasteurized milk Clostridium Botulinum Botulism Improperly canned food Escherichia Coli Travelers’ diarrhea Water or food contaminated with human feces Hepatitis A Hepatitis Raw produce, contaminated water, uncooked/improperly reheated food Listeria Monocytogenes Listeriosis Unpasteurized dairy products, ready-to-eat deli meats 02 Handout 1 *Property of STI  [email protected] Page 1 of 7  TH2203 Organism Name of Illness Sources Noroviruses Viral gastroentiritis Raw produce, contaminated water, uncooked/improperly reheated food Salmonella Salmonellosis Eggs, poultry Staphylococcus Aureus Staph food poisoning Unrefrigerated meats Shigella Shigellosis or Bacillary Raw produce, contaminated water, uncooked/improperly dysentery reheated food Lifted and modified from What you need to know about foodborne illnesses (2019). US Food and Drug Administration. https://www.fda.gov/food/consumers/what-you-need-know-about-foodborne- illnesses The most common signs and symptoms when afflicted with these foodborne illnesses are abdominal cramps, watery diarrhea, nausea, vomiting, fatigue, and fever. In some worst cases, people experience weakened immune systems, kidney failure, respiratory failure, stillbirth, meningitis, and death (US FDA, 2019). An incident is considered a foodborne disease outbreak if two (2) or more people experience a similar illness after eating a common food (US FDA, n.d.). Biological Hazards The most common biological hazard is bacteria in food. Bacteria are single-celled microorganisms. Some bacteria are beneficial, like those that aid in the digestion of food or those used in making cheese and yogurt. Bacteria that are dangerous when consumed by humans are called pathogens (Labensky et al., 2018). Pathogens cause foodborne illnesses in three (3) ways (Gisslen, 2016): Intoxications (food poisoning) occur when a pathogen produces a toxin(s) while growing in food before it is eaten. Upon consumption of a sufficient quantity of “poisoned food,” the host becomes ill. Botulism and staphylococcal food poisoning are the best-known foodborne intoxications. Viruses and parasites do not cause intoxication. Infections are caused when viable food pathogens survive through the host’s stomach into the intestine. Some bacteria, all viruses, and parasites cause illness via infection. Toxin-mediated infection is caused by eating food that contains harmful microorganisms that will produce a toxin once inside the human body. The reproduction of bacteria and the increase in Figure 1 the number of organisms is called bacterial Bacterial Growth Curve growth. When bacteria are moved from one place to another, they require time to adjust to new conditions and grow. This resting period, during which very little growth occurs, is known as the lag phase and may last from 1 - 4 hours. It is followed by the log phase, a period of accelerated growth, and then by the stationary phase, which lasts until the bacteria crowd others within their colony, creating competition for food, space, and moisture. This begins the decline or negative-growth phase, during which bacteria die at an accelerated rate (Labensky et al., 2018). The rate of bacterial growth is represented in Figure 1. Lifted from On Cooking: A Textbook of Culinary Fundamentals (p. 61) by S. R. Labensky, A. M. Hause, and Martel, P. A. (5th Ed., 2018). Copyright 2018 by Pearson. 02 Handout 1 *Property of STI  [email protected] Page 2 of 7  TH2203 Certain conditions in food allow for bacterial growth. These conditions are (Gisslen, 2016):  Food. A suitable food supply is an essential condition needed for bacterial growth. Most bacteria prefer food high in protein or carbohydrates like meats, poultry, seafood, dairy products, and cooked rice, beans, and potatoes.  Acidity. Most food items are acidic and have a pH of less than 7.0. The pH symbol is used to designate the acidity or alkalinity of a food. pH is measured on a scale that ranges from zero to 14. Very acidic food (pH below 4.6) like lemon, limes, and tomatoes will not normally support/slow down the growth rate of disease-causing bacteria. Most bacteria prefer a neutral environment (pH of 7.0) but can grow in food items with a pH of 4.6 to 9.0. A pH above 7.0 indicates that a food is alkaline, like olives, egg whites, or soda crackers. Hence, disease-causing bacteria grow best when the food it lives on has a pH of 4.6 to 7.0, like meat, fish, and milk.  Temperature. All bacteria do not have the same temperature requirements for growth. Most disease- causing bacteria can grow within a temperature range of 41°F to 135°F (5°C to 57°C), most commonly referred to as the food Temperature Danger Zone (TDZ). Temperature abuse is applied to food items that have not been heated to a safe temperature or kept at an improper temperature.  Time. Under ideal conditions, bacterial cells can double in number every 15 to 30 minutes. For most bacteria, a single cell can generate over one (1) million cells in just five (5) hours. A rule of thumb in the foodservice industry is that bacteria need about four (4) hours to grow to high enough numbers to cause illness.  Oxygen. Bacteria also differ in their requirements for oxygen. However, controlling oxygen conditions may not be an effective way to prevent foodborne illness. Regardless of available oxygen, some disease-causing bacteria will find the conditions suitable for growth.  Moisture. Like most other life forms, moisture is essential in bacterial growth. Scientists have determined that it is not the percentage of moisture or “water by volume” in food that most affects bacterial growth. Instead, it is the amount of “available water” or water available for bacterial activity. Water activity (Aw) is a measure of the amount of water that is not bound to the food and is, therefore, available for bacterial growth. Aw is measured on a scale of 0-1.0. Disease-causing bacteria can only grow in food items with an Aw higher than 0.85. The best way to prevent bacterial intoxications and infections is to attack the factors bacteria need to survive and multiply. Other biological hazards are viruses, parasites, and fungi: Viruses are much smaller than bacteria, and these require a living host (human, animal) in which to grow and reproduce. Viruses do not multiply in food. However, a susceptible person can experience an infection with only a few viral particles consumed (Gisslen, 2016). Parasites are microscopic creatures that need to live on or inside a living host to survive. They take nourishment from their host. Parasitic infection is far less common than bacterial or viral foodborne illnesses (Gisslen, 2016). Fungi range from single-celled to multicellular organisms. These include yeasts, molds, mildews, and mushrooms. Some fungi are harmless to humans, while some can cause diseases. 02 Handout 1 *Property of STI  [email protected] Page 3 of 7  TH2203 Chemical and Physical Hazards (Gisslen, 2016) Some kinds of chemical poisoning are caused by using defective or improper equipment or equipment handled improperly. Other chemical contamination can result from exposure of food items to chemicals used in commercial food-service establishments. Examples include cleaning compounds, polishing compounds, and insecticides. Prevent contamination by keeping these items physically separated from food. Do not use them around food. Examples of physical contaminants include pieces of glass from a broken container, metal shavings from an improperly opened can, stones from poorly sorted dried beans, soil from badly washed vegetables, insects or insect parts, and hair. Proper food handling is necessary to avoid physical contamination. Proper Food Handling Temperature and Time The two (2) major sanitation problems when handling and preparing food are cross-contamination and the TDZ. Food should be kept out of the TDZ whenever possible. The 10 common causes of foodborne illnesses are:  Improper cooling  Contaminated raw food or ingredient  Advance preparation  Unsafe sources  Infected person  Use of leftovers  Inadequate reheating for hot holding  Cross-contamination  Improper hot holding  Inadequate cooking Because of the lag phase, food items can be in the TDZ for very short periods during preparation without an unacceptable increase in bacterial growth. However, exposure to the TDZ is cumulative and should not exceed four (4) hours. The less time food is in the TDZ, the less opportunity bacteria can multiply. As a rule, keep hot food hot, cold food cold, and frozen food frozen (Labensky et al., 2016). Table 2 highlights the common temperatures that food handlers must be aware of most of the time. Table 2 Important Temperatures to Remember Celsius Fahrenheit Description 100°C 212°F Water boils Cooking temperature range; most disease-causing organisms are killed in a 74°C and above 165°F and above few minutes Hot food holding temperature range; bacteria do not multiply, but most 57-74°C 135-165°F are not killed 5-57°C 41-135°F Temperature danger zone; bacteria multiply rapidly Cold food storage/refrigeration; food is safe for a short period/little 0-5°C 41-32°F bacterial growth 0°C 32°F Water freezes -18-0°C 0-32°F Subfreezing; bacteria do not grow, but most are not killed Freezer storage; bacteria do not grow, but most are not killed—best -18°C and below 0°F and below temperatures for frozen food storage Adapted from Essentials of Professional Cooking (p. 18) by W. Gisslen (2nd Ed., 2015). Copyright 2015 by Wiley To ensure that food items being cooked are safe, they must reach their minimum internal cooking temperature. Minimum internal cooking temperature is the internal temperature for a food product at which microorganisms are killed. The product must be held at that temperature for a specified period to be safe. Each food item has a different minimum internal cooking temperature (Gisslen, 2016). Some of these are: For beef, pork, veal, or lamb: Cook to 145°F/63°C for four (4) minutes. 02 Handout 1 *Property of STI  [email protected] Page 4 of 7  TH2203 For eggs: Cook until the yolk and white are firm OR cook to 145°F/63°C for 15 seconds. For fish and shellfish: Cook to 145°F/63°C for 15 seconds; shells should open. For poultry or wild game: Cook to 165°F/74°C for 15 seconds. Safe Food Handling Guidelines (Gisslen, 2016)  Start with clean, wholesome, or fresh food items from reputable suppliers. Buy government-inspected meats, poultry, fish, dairy, and egg products whenever applicable.  Handle food as little as possible. Use clean tongs, spatulas, or other utensils instead of hands when practical.  Use clean, sanitized equipment and worktables.  Clean and sanitize cutting surfaces and equipment after handling raw poultry, meat, fish, or eggs and before working on another food item.  Use different chopping boards for different items to avoid cross-contamination. Generally, chopping boards are color-coded as red for raw meats, yellow for raw poultry, blue for fish and shellfish, green for vegetables and fruits, white for dairy products, and brown for cooked food. Commercial kitchens may use a different color-coding scheme depending on their needs.  Clean as you go. Do not wait until the end of the workday. Keep clean clothes and sanitizing solutions handy at workstations and use them often.  Wash raw fruits and vegetables thoroughly.  When bringing food items out of refrigeration, do not bring out more than what can be processed in an hour.  Keep food covered unless for immediate use.  Limit the time that the food spends in the TDZ. Observe the four-hour rule.  Four-hour rule: Do not let food remain in the TDZ for a cumulative total of more than four (4) hours between receiving and serving.  Taste food properly. With a ladle or other serving implement, transfer a small amount of the food to a small dish. Then, taste the sample using a clean spoon. After tasting, do not use either the dish or the spoon again. Send it to the dishwashing station or, if using disposables, discard it.  Boil leftover gravies, sauces, soups, and vegetables before serving.  Do not mix leftovers with freshly prepared food items.  Chill all ingredients for protein salads and potato salads before combining.  Cool and chill food quickly and correctly. Chill custards, cream fillings, and other hazardous food items as soon as possible by pouring these into shallow, sanitized pans, covering, and refrigerating them. Packaging Prepared Food Food packaging comes in different materials like paper and paperboard, metals, glass, and plastics. Packaging should function as (Sedlacekova, 2017): Containment – Conceal product and its parts and prevent them from spillage and loss, starting from the packing line through transportation phases until it arrives at the customer’s home. 02 Handout 1 *Property of STI  [email protected] Page 5 of 7  TH2203 Protection – Prevent outside forces like temperature, humidity, contact, and potential hazards from intervening with the product inside. Preservation – Keep products in a controlled environment to remain safe for longer use. Convenience – The product should be convenient to carry, transport, and open while safely maintaining inside items. Information – This contains data for tracking, product information, and marketing and brand information. Materials used for packaging food should be suitable for food contact to ensure that they do not contain any chemicals that may leach into the food. According to Australia New Zealand Food Standards Code, to prevent risks and hazards when packaging food, a food business must:  Only use packaging materials that are fit for their intended use.  Only use a material that is not likely to cause food contamination.  Ensure that there is no likelihood that the food may become contaminated during the packaging process. Handling Convenience Food Items (Gisslen, 2016) Convenience food is any food product that has been partially or completely prepared or processed by a manufacturer. Processed food for restaurants and institutions ranges from partially prepared items that can be used as components in recipes, such as frozen fish fillets, peeled potatoes, concentrated stock bases, and frozen puff pastry doughs, to fully prepared items that only need to be reconstituted or served as is, such as frozen prepared entrées and frozen pies and pastries. There is no substitute for quality and care, no matter what products are used. Fresh product is potentially the best, but not if it is badly stored or handled. Similarly, convenience food items also require proper handling to maintain their quality. Guidelines for Handling Convenience Food  Handle with the same care as fresh, raw ingredients. Most loss of quality in convenience food comes from assuming that these are damage-proof and can be treated haphazardly.  Examine as soon as received. Particularly, check frozen food with a thermometer to ensure it did not thaw in transit.  Store properly. Frozen food must be held at -18°C (0°F) or lower. Regularly check the freezer with a thermometer. To slow spoilage, refrigerated food items must stay chilled or below 5°C (41°F). Shelf- stable food items (e.g., dry products, canned goods) are stable only when tightly sealed and stored properly in a cool, dry place.  Know the shelf life of each product. Nothing lasts forever—not even convenience food items. Rotate stock according to the first in, first out principle*. Do not stock more than necessary. *First In, First Out (FIFO) is a storing method or principle where deliveries or stocks are rotated to ensure that the old ones are used first. Old stocks are moved out of storage, and new deliveries are placed first (at the back or last part) in the storage. Then, old stocks are returned and placed last (in front).  Defrost frozen food properly. Ideally, defrost in a tempering box set at -2°C to -1°C (28°F to 30°F) or in the refrigerator at 5°C (41°F) or lower. This takes planning and timing because large items take several days to thaw. If short of time, the second-best way to defrost food is under cold running water in its original wrapper. Do not defrost at room temperature or in warm water. The high temperatures 02 Handout 1 *Property of STI  [email protected] Page 6 of 7  TH2203 encourage bacterial growth and spoilage. Do not freeze thawed food, for its quality will greatly deteriorate.  Know how and to what extent the product has been prepared. Partially cooked food needs less heating in the final preparation than raw food. Manufacturers indicate full directions and serving suggestions for their products on their labels. Consumers must read and follow the package directions.  Use proper cooking methods. Be flexible when needed. Most modern pieces of equipment are designed especially for convenience food. Do not restrict to conventional ranges and ovens if compartment steamers or microwave ovens can do a better and more efficient job.  Treat convenience food as though you, not the manufacturer, did the preparation. Make the most of the opportunity to use one’s creativity to serve the best quality products. The final preparation, plating, and garnish should be done carefully as if the dishes were all made from scratch. References: Gisslen, W. (2015). Essentials of professional cooking (2nd Ed.). Wiley. Labensky, S.R., Martel, P.A., & Hause, A.M. (2018). On Cooking: A textbook of culinary fundamentals (6th Ed.). Pearson. Sedlacekova, Z. (6 November 2017). Food packaging materials: Comparison of materials used for packaging purposes (Baccalaureate thesis). Retrieved from http://www.theseus.fi/handle/10024/1371943 US Food and Drug Administration. (n.d.). Outbreaks of foodborne illness. Retrieved on July 21, 2022, from https://www.fda.gov/food/recalls-outbreaks-emergencies/outbreaks-foodborne- illness#:~:text=When%20two%20or%20more%20people,from%20happening%20in%20the%20future. World Health Organization. (May 19, 2022). Foodsafety. Retrieved on July 21, 2022, from https://www.who.int/news-room/fact-sheets/detail/food- safety#:~:text=Foodborne%20illnesses%20are%20usually%20infectious,term%20diseases%2C%20suc h%20as%20cancer US Food and Drug Administration. (2019). What You Need to Know about Foodborne Illnesses. Fda.gov. Retrieved on July 22, 2022, from https://www.fda.gov/food/consumers/what-you-need-know-about- foodborne-illnesses 02 Handout 1 *Property of STI  [email protected] Page 7 of 7