Microorganisms & Sanitation :Microorganisms & Sanitation Dr. Deryck D. Pattron, Ph.D.


What are microorganisms? :Derived from the Greek word meaning “small living beings” These organisms cannot be seen with the unaided eye. Believed to be discovered by Anton van Leeuwenhoek in 1693. Approx. 200 years later Pasteur established the relationship between microorganisms and diseases. Most or all human foods are rich in nutrients that can be utilized by microorganisms. Control of microbial proliferation is necessary to reduce food spoilage and to eliminate foodborne illness. What are microorganisms?


Microorganisms in Food :Moulds Multicellular organisms with mycelial morphology. Display a variety of colours. Generally recognized by fuzzy, cotton like appearance. Produce numerous spores that are released in the air. Withstand fluctuations in pH. Most moulds thrive best at or a near a pH of 7.0, but a pH of 2 to 8.0 can be tolerated. Growth can occur below 0 C. Optimal mould growth occurs at aw = 0.85 and at aw = 0.80 Microorganisms in Food


Microorganisms in Food :Yeasts Unicellular organism. Reproduce asexually by budding. Spread through the air and can alight on any surface of food or food item. Yeast colonies generally moist and slimy in appearance and cream white coloured. Yeast prefer aw = 0.90-0.94, but can grow below 0.90. Yeast grows best at pH 4.0-4.5. Food contaminated with yeast have a slight fruity odour. Microorganisms in Food


Microorganisms in Food :Bacteria Unicellular organisms. Approximately 1 mm in diameter. Morphological variations Elongated rods e.g. Streptococci. Spherical forms in bunches e.g. staphylococcus. Ovoid forms e.g. Some possess flagella and are motile. Some produce colour pigments , such as shades of yellow, brown or black, blue, red, pink, orange, green and purple. Microorganisms in Food


Food Contamination Sources :Food and food products are contaminated with soil, air, and waterborne microorganisms. Harvesting, processing, distribution, and preparation generally leads to contamination of foods. Significant numbers of microorganisms are found in animals’ intestinal tracts, carcasses surfaces during slaughter. Some apparently healthy looking animals may harbour microorganisms in their kidneys, liver, lymph nodes, and spleen. Poor slaughtering practices may lead to contamination of muscles via the circulatory system. Food Contamination Sources


Chain of Infection :A series of related events or factors such as agent, source, mode of transmission, and host that must exist or occur and be linked together before an infection will occur. Links in the chain of infection: A source and reservoir of transmission for each agent. Transmission of the causative agent from the environment or source to the food. Growth of the microorganism through the food or host. Chain of Infection


Web of Causation :A complex flow chart that indicates the factors that affect the transmission of foodborne disease. If raw products are not handled in a sanitary manner, they become contaminated and readily support microbial growth. Web of Causation


Contamination of Poultry :Vulnerable to contamination by Salmonella during processing. Defeathering and evisceration allows easy distribution among carcasses. Contaminated hands, gloves, and equipment. Transovarian transmission of Salmonella. Contamination of Poultry


Contamination of Red Meats :The muscle tissue in healthy animals are nearly always free of microorganisms. Contamination of red meat occurs from the external surface such as hair, skin, gastrointestinal and respiratory tracts. Contamination of carcass with the hide, feet, manure, dirt and visceral contents from punctured digestive organs. Contamination of Red Meats


Contamination of Seafood :Excellent sources of proteins, B vitamins, minerals such as sulphur, calcium, phosphorus, magnesium, iron, copper, iodine, fluorine, manganese, zinc, lead and arsenic. Extensive handling of seafood from harvesting to consumption. Frequent storage for long periods without proper refrigeration. Contamination of Seafood


Contamination of Dairy Products :Contamination through udder of cows and milking equipment. Pasteurization of milk as a means of eliminating all milk-borne microorganisms. Contamination of Dairy Products


Contamination of Fruits & Vegetables :Soil contamination-heat resistant bacteria are present in the ground and can cause flat-sour and spoilage of canned vegetables. Water contamination-via contaminated irrigation systems before harvesting and drying. Pest contamination-via bacteria, yeasts, mould, and viruses and parasites. Human contamination-through poor sanitation and personal hygiene practices. Contamination of Fruits & Vegetables


Contamination from Ingredients :Ingredients are potential sources of harmful microorganisms and toxins. Ingredients tend to be multinational in origin. Quality assurance and safety cannot be guaranteed in countries that do not have established food safety and quality assurance systems. Adulteration, whether intentionally or otherwise may readily occur with ingredients. Sudan red has been found with certain spices. Contamination from Ingredients


Protection against Contamination :Protection against the environment. Protection during storage and transport. Protection against contamination from litter and garbage. Protection against toxic substances. Protection against Contamination


Food Establishment :Food Establishment


Design & Maintenance of the Food Preparation Areas :Food preparation is an important aspect of processors, handlers and all stakeholders including manufacturers, distributors and processors. Proper food preparation is essential for health and safety for all consumers. Food preparation areas are important areas of concern, since they represent areas where food is produced or handled in some way for human consumption. Food preparation areas must be designed appropriately and built according to the required specifications. Design & Maintenance of the Food Preparation Areas


Properly Designed Food Preparation Rooms-Why? :The preparation area layout should be appropriately designed and equipped making food preparation easier and more effective with less occurrence of near misses, incidents and accidents. The preparation area is tightly secured with close fitting doors and vent guards, proper lighting, ventilation, easy to clean and sanitize and provide conditions that would encourage good hygienic practices. Properly Designed Food Preparation Rooms-Why?


Degree of Risk of Food Areas :The degree of risk associated with food preparation areas depends on: Type of food. Use of area. Durable surfaces should be placed on areas which receive heavy traffic, trolleys, personnel etc. Facilities for cross contamination. Small working areas increase the risk of cross contamination. Quality of staff employed. Intended consumer. YOPI’s are most susceptible. Degree of Risk of Food Areas


General Areas of a Food Establishment :Receiving and delivery. Storage. Preparation. Holding. Service. Ware washing. Garbage storage and pickup. Food display area. Housekeeping. Toilet facilities. General Areas of a Food Establishment


Regulatory Considerations :Health. Safety. Building. Fire. Zoning. Environmental code standards. Regulatory Considerations


Work Center Planning :Efficient production. Fast service. A pleasant environment. Effective cleanup. Work Center Planning


Equipment Selection :Design. Construction. Durability. Ability to clean easily. Size. Cost. Safety. Effectiveness. Marking of approval. Equipment Selection


Types of Equipment :Ovens. Range oven. Deck oven. Convection oven. Steam jacketed kettles. Refrigerator and low temperature storage equipment. Reach-in-refrigerators. Walk-in-refrigerators. Cook-chill and rapid-chill systems. Slicers. Mixers. Grinders. Choppers. Ice machines. Dishwashing equipment. Types of Equipment


Construction Materials :FDA Food Code Smooth. Seamless. Easily cleanable. Easy to take apart. Easy to reassemble. Equipped with rounded corners and edges. Non-toxic. Not impart colour, odour or taste to foods. Stainless steel is a preferred material for food-contact surfaces. Construction Materials


Construction Materials :Metals e.g. chromium and nickel. Stainless steel. Plastic e.g. acrylics used to make covers for food containers, melamines used to make dishes and glassware, fiberglass used to make boxes and trays, polyethylene used to make equipment with moving parts, polypropylene used to make dishwashing racks. Wood. The FDA Food Code permits the use of hard maple or equally hard close-grained wood for cutting boards and baker’s tables. Construction Materials


Classification of Work Areas in Food Establishment :Classification of Work Areas in Food Establishment


Class 1 Areas :Highest risk areas that contain hazards which contribute to danger if surfaces are not thoroughly cleaned. Food preparation kitchens. Pre-cooked foods and meats. Class 1 Areas


Class 2 Areas :Moderate risk areas of contamination. Raw perishable foods. Class 2 Areas


Class 3 Areas :Areas with low levels of contamination. Dry stores containing dried goods such as flour, bran etc. Class 3 Areas


Class 4 Areas :Areas of lowest contamination. Class 4 Areas


Critical Thinking 2: :Draw a floor plan for a food service facility that deals with (a) short order cooking (b) long order cooking. Case Study: Ms Charles is a deli manager. She has been given permission to purchase a new slicer for the department. What strategy should Charles use when purchasing the new slicer? What factors should Charles use to determine the deli’s need for the slicer? What design and construction features should Charles use when she is making comparisons between slicers? What standard organizations might Charles consult when evaluating different kinds of slicers? Critical Thinking 2:


Cleaning & Sanitizing Operations :A number of persons contracted Hepatitis A virus after consuming food at a Bar in Trinidad. Public health inspectors discovered that poor food-handling and personal hygiene techniques used by employees were responsible. It was found that lack of hand washing prior to food preparation and the transfer of salad materials by bare hands from a bulk container onto serving plates rather than using tongs. Interviews with employees revealed that at least eleven employees have recently worked while having diarrheal diseases. Cleaning & Sanitizing Operations


Principles of Cleaning & Sanitizing :Cleaning is the physical removal of soil and food residues from surfaces of equipment and utensils. Sanitizing is the treatment of a surface that has been previously cleaned to reduce the number of disease-causing microorganisms to safe levels. Principles of Cleaning & Sanitizing


Cleaning Steps :A detergent or soap is brought into contact with the soil. The debris or soil is loosened from the surface being cleaned. The loosened residue or soil is dispersed in water. The dispersed soil or debris is rinsed away along the detergent to prevent it from being redeposited onto the surface. Cleaning Steps


Removal of Food Particles :Scrape of flush food particles. Application of cleaning agents. Cleaning agents typically include an acid or alkaline and may include degreasers, abrasive materials or sanitizers. Soaking for a few minutes. Spray methods. Cleaning solutions can be sprayed on equipment surfaces using hot water or stream. Clean-in-place systems. This methods relies on the strength and velocity of the cleaning solutions moving through the system. Abrasive cleaning include paste and powders used to remove soil. Rinsing. This should be achieved with hot potable water to remove cleaning solution. Removal of Food Particles


Factors Affecting Cleaning Efficiency :Type of soil to be removed. Food deposits. Mineral deposits. Microorganisms. Fats and oils. Dirt and debris. Water quality. Portable water. The detergent or cleaner used. Water temperature. Water velocity or force. Time detergent remains in contact with the surface. The concentration of cleaner. Factors Affecting Cleaning Efficiency


Detergents & Cleaners to be Used :Detergent-cleaning or purifying agent. Derived from the latin word detergeo “to wipe away”. Detergents can be improved by adding soap, alkali, acids, degreasers, abrasive cleaners, other cleaning agents. Detergents & Cleaners to be Used


Water Temperature :Heat stable detergents work best at 54 °C to 71 °C. The temperature should be sufficient to remove soil and debris, but not hot enough to bake soil onto food contact surfaces. A good rule of thumb is to use cold-water detergents at tap-water temperature. Water Temperature


Cleaning Frequency :FDA Code requires that food contact surfaces used with potentially hazardous foods must be cleaned: At least every 4 hours. Before each use with a different type of raw animal food. Each time there is a change from working with raw foods to working with ready-to-eat foods. Before using or storing a food temperature-measuring device. At any time during the operation when contamination may have occurred. Cleaning Frequency


Exceptions to FDA Food Code 4-h Rule :During storage, containers of potentially hazardous food. Contents of containers containing food held at hot and cold temperatures. When utensils and equipment are used to prepare potentially hazardous food in a refrigerated room. Exceptions to FDA Food Code 4-h Rule


Prescribed Temperature & Cleaning Frequency :Prescribed Temperature & Cleaning Frequency


Sanitizing Principles :Heat and chemicals are the most commonly used sanitizers in the food industry. Heat sanitizers Can penetrate cracks and crevices. Is non-corrosive to metals. Leaves no residues. Can be controlled. Heat destroys spores as well as bacteria cells by denaturing proteins in the cell walls. Moist heat kills bacteria more efficient than dry heat. Sanitizing Principles


Heat Sanitizing in ware washing Operations :Immersing cleaned equipment and utensils in hot water for at least 30 sec. maintained at 77 °C. The FDA Food Code requires a temperature of not less than 82 ° C for hot water sanitizing rinse in mechanical ware washers. Heat Sanitizing in ware washing Operations


Chemical Sanitizing :Chlorine-commonly used in retail food establishments. Hypochlorites offer many advantages as sanitizers. Calcium hypochlorite contains 70 % available chlorine. Control a wide range of microorganisms. Deodorize and sanitize. Non-toxic when used as prescribed by the manufacturer. Easy to handle. Economical to use. FDA Food Code requires food contact surfaces to be exposed to 50 ppm for at least 7 sec when the chlorine solution has a pH = 10 and a water temperature of 38 ° C or a pH = 8 and a water temperature of at least 24 ° C. Chemical Sanitizing


Iodine :Iodine containing compounds used in retail food establishments-Iodophors. Function best in water at low pH at temperatures 24 ° C and 49 ° C. Food-contact surfaces must be exposed for at least 30 sec. Iodine


Quaternary Ammonium Compounds (quats) :Ammonia salts that are used in retail establishments. Effective sanitizers, but do not destroy a range of microorganisms. The FDA Food Code requires that quats used at 200 ppm for 30 sec. Quats are: Non-corrosive. Non-irritating to skin. Heat stable. Work well at temperatures 24 ° C and above. Quaternary Ammonium Compounds (quats)


Advantages & Disadvantages of Sanitizers :Advantages & Disadvantages of Sanitizers


Employee Safety :OSH Act 2004/2006 requires that employees have the right to know about hazardous chemicals. Information about hazardous chemicals is provided in the MSDS. Information included in the MSDS sheet: Ingredients. Physical and chemical characteristics. Fire, explosion and health hazard data. How to handle hazardous chemicals. How to use personal protective equipment and other devices to reduce risk. Emergency procedures to use if required. Employee Safety


Conclusion :A good sanitation programme starts with a clean and properly maintained building. A well maintained facility protects food products from contamination and anticipates and eliminates potential hazards through effective monitoring and adoption of timely corrective actions. Conclusion


Critical Thinking 2 :A Salmonella outbreak occurred in small rural village in Trinidad. One hundred and seven confirmed cases and 45 probable cases were detected. The illness was caused by eating poorly coked beef steak. Upon investigation it was found that the cutting boards and utensils were not washed and sanitized prior to and after cooking. 1. What went wrong? 2. How could this outbreak have been prevented? Critical Thinking 2


Reference :McSwane, D, Rue, N.R, Linton, R. 4th ed. 2005. Essentials of Food Safety and Sanitation. New Jersey: Pearson. Reference