L1 Food and Environmental Hygiene I 2024 PDF

Lecture 1 Food and Environmental Hygiene I FNSC5430/LSCI6843 Food Toxicology and Safety Gordon Cheung B.Sc.(Hons.), Pg.D. Diet., M.Phil., Cert. Chi. Med., R.D.(UK)​​  Content Introduction of the conten...

Lecture 1 Food and Environmental Hygiene I FNSC5430/LSCI6843 Food Toxicology and Safety Gordon Cheung B.Sc.(Hons.), Pg.D. Diet., M.Phil., Cert. Chi. Med., R.D.(UK)​​  Content Introduction of the content of the course regarding food safety Introduction to Food Safety Hazards in Foods leading to Food-borne Illnesses Food Hygiene in Food and Catering Industry Food Hygiene During Food Handling  Overview of the First Half of the Course (7 Weeks) Food Safety Food and Environmental Hygiene Food Poisoning and Spoilage Food Legislation Food Safety Control Risk Management in Food Safety  Overview of the First Half of the Course (7 Weeks) Learning objectives: To understand basic concepts and guidelines of food safety and regulation To understand the food hygiene management and policy Assessment: Mid-term examination at week 7 2 hours, closed book MCQs + short/long questions Food and Environmental Hygiene  Importance of Food Safety Food is essential for human life because it is the source of energy and nutrients Energy supports the activities of human body whereas nutrients are vital for group, repair and maintenance of good health In undeveloped or developing countries where people are starving, food is supplied as basic necessity However, no matter what is the case and where the people are, it is considered that people should have access to safe food supply  Importance of Food Safety Food safety is related to the presence of food-borne hazards in food at the point of consumption As the introduction of food safety hazards can occur at any stage of the food chain, hence, food safety is ensured through the combined efforts of all the parties participating in the food chain To lay a firm foundation against food-borne illnesses, there are general principles to be adhere in order to produce clean and safety food  Food Safety With an estimated 600 million cases of foodborne illnesses annually, unsafe food is a threat to human health and economies globally Getting even more complicated with globalization of food supply Usually draw much media and public attentions It receives disproportionate coverage e.g. Asian Avian influenza, gutty oil in Taiwan  Food Safety Keeping food safe is a complex process that starts on the farm and ends with the consumer Truly the responsibility of food trades, government and consumers From farm to table approach Effective food safety and quality control systems are key not only to safeguarding the health and well-being of people, but also to fostering economic development and improving livelihoods by promoting access to domestic, regional and international markets  Food Safety - Definition Food Safety: Assurance that food will not cause harm to the consumer when it is prepared and /or eaten according to its intended use Free from harmful substances Food Hygiene: All conditions and measures necessary to ensure the safety and suitability of food at all stages of the food chain Food Suitability: Assurance that food is acceptable for human consumption according to its intended use.  Cause of Food-Borne Illness Food can become unsafe in several ways. Hazards to food are present in the air, in water, in other foods, on work surfaces, and on a food preparer’s hands and body These hazards can be divided into three categories : Biological Bacteria, viruses, parasites, moulds, yeast Chemical Pesticides, heavy metal, cleaning chemicals Physical Dirt, hair, broken glass, metal shaving, plastic, bones  Bacterial Food Infections Pathogen Latency Period Principal Symptoms Typical Foods Listeria 3–70 days Meningoencephalitis; Raw milk, cheese, and monocytogenes (up to 1 month) stillbirths; septicaemia or vegetables meningitis in newborns Salmonella species 12–36 hr (2–7 Diarrhea, abdominal pain, Raw, undercooked eggs; days) chills, fever, vomiting, raw milk, meat, and poultry dehydration Shigella species 12–48 hr (4–7 Diarrhea, fever, nausea; Raw foods days) sometimes vomiting, cramps Streptococcus 1–3 days (varies) Various, including sore throat; Raw milk, deviled eggs pyogenes erysipelas, scarlet fever  Bacterial Food Infections Pathogen Mode of Contamination Prevention of Disease Listeria Soil or infected Pasteurization of milk; cooking monocytogenes animals, directly or via manure Salmonella species Infected food-source Cook eggs, meat, and poultry thoroughly; animals; human feces pasteurize milk; irradiate chickens Shigella species Human fecal contamination, General sanitation; cook foods thoroughly direct or via water Streptococcus Handlers with sore throats, other General sanitation; pasteurize milk pyogenes “strep” infections  Bacterial Food Intoxicants Pathogen Latency Principal Symptoms Typical Foods Period Clostridium 12–36 hr Fatigue, weakness, double Types A & B: vegetables, fruits; botulinum (months) vision, slurred speech, meat, fish, and poultry products; (botulism) respiratory failure, sometimes condiments; Type E: fish and fish death products Clostridium 8–24 hr Diarrhea, cramps, rarely Cooked meat and poultry perfringens (12–24 hr) nausea and vomiting Bacillus 6–15 hr Diarrhea, cramps, Meat products, soups, cereus (12–24 hr) occasional vomiting sauces, vegetables (diarrheal) Bacillus 1/2–6 hr Nausea, vomiting, Cooked rice and pasta cereus (5–24 hr) sometimes diarrhea and (emetic) cramps Staphylococcu 1/2–8 hr Nausea, vomiting, diarrhea, Ham, meat, poultry products,  Bacterial Food Intoxicants Pathogen Mode of Contamination Prevention of Disease Clostridium Types A & B: soil or Thorough heating and botulinum dust; Type E: water rapid cooling of foods (botulism) and sediments Clostridium Soil, raw foods Thorough heating and perfringens rapid cooling of foods Bacillus cereus From soil or dust Thorough heating and (diarrheal) rapid cooling of foods Bacillus cereus From soil or dust Thorough heating and (emetic) rapid cooling of foods Staphylococcus Handlers with colds, Thorough heating and aureus sore throats or infected rapid cooling of foods cuts; food slicers  Bacterial Toxin-Mediated Infections Pathogen Latency Principal Symptoms Typical Foods Period Campylobacter 2–5 days Diarrhea, abdominal pain, Infected food- jejuni (2–10 days) fever, nausea, vomiting source animals Vibrio cholerae 2–3 days Profuse, watery stools; sometimes Raw or (cholera) (up to 7 days) vomiting; dehydration; often rapidly undercooked fatal if untreated Seafood Vibrio para- 12–24 hr Diarrhea, cramps; sometimes nausea, Fish and seafood haemolyticus (4–7 days) vomiting, fever; headache Escherichia coli 12–60 hr Watery, bloody diarrhea Raw or (enterohemorr-hagic) (2–9 days) undercooked beef, raw milk Escherichia coli at least 18 hr Cramps, diarrhea, fever, dysentery Raw foods (enteroinvasive) (uncertain)  Bacterial Toxin-Mediated Infections Pathogen Mode of Contamination Prevention of Disease Campylobacter Chicken, raw milk Cook chicken thoroughly; avoid cross jejuni contamination; irradiate chickens; pasteurize milk Vibrio cholerae Human feces in marine Cook seafood thoroughly; general (cholera) Environment sanitation Vibrio para- Marine coastal environment Cook fish and seafood thoroughly haemolyticus Escherichia coli Infected cattle Cook beef thoroughly (enterohemorrhagic) Escherichia coli Human fecal contamination, Cook foods thoroughly; general (enteroinvasive) direct or via water sanitation Escherichia coli Human fecal contamination, Cook foods thoroughly; general (enterotoxigenic) direct or via water sanitation  Viral Food-borne Pathogens Pathogen Latency Period Principal Symptoms Typical Foods Hepatitis A virus 10–50 days Fever, weakness, discomfort, Raw or undercooked shellfish; (2 wk to 6 mo) nausea; often jaundice sandwiches, salads, etc Norwalk-like 1–2 hours Nausea, vomiting, diarrhea, pains, Raw or undercooked shellfish; viruses (1–2 days) headache, mild fever sandwiches, salads, etc. Rotaviruses 1–3 days Diarrhea, especially in infants and Raw or mishandled foods (4–6 days) young children Pathogen Mode of Contamination Prevention of Disease Hepatitis A virus Human fecal contamination, via Cook shellfish thoroughly; general water or direct sanitation Norwalk-like Human fecal contamination, via Cook shellfish thoroughly; general viruses water or direct sanitation Rotaviruses Probably human fecal General sanitation contamination  Other Biological Hazards Parasites (roundworms, protozoa) Roundworms in raw/undercooked pork and fishes Protozoa from unclean water Prions causing mad cow disease (Bovine Spongiform Encephalopathy, BSE) Prion is protein in nature traveling up the spinal cord to the brain and causing chain reactions that make the brain “porous”  Potential Chemical Hazards Additives / Plant Toxins Animal Toxin Metals Contaminants Pesticides Raw or undercooked Certain seafood Heavy metals Herbicides red kidney beans or toxins Arsenic fava beans Tetrodotoxin Fertilizers Lead Certain mushrooms Ciguatoxin Industrial chemicals Cadmium Certain herbs Acrylamide Mercury Fruit pits Benzene Other metals Mold toxins Pollutants Copper (mycotoxins) Dioxins Zinc Polycyclic aromatic hydrocarbons Cleaning products  Classification of Carcinogenic Agents by IARC Group Description No. of Compounds and Examples Group 1 Carcinogenic to humans 121 Evidence is sufficient in humans (e.g. Aflatoxin, processed meat, dioxin) Group 2A Probably carcinogenic to humans 88 Evidence is limited in humans, and is sufficient in experimental (e.g. Acrylamide, red animals meat, very hot beverage) Group 2B Possibly carcinogenic to humans 313 Evidence is limited in humans, and is less than sufficient in (e.g. Kava extract, lead) experimental animals; or Evidence is inadequate in humans, but is sufficient in experimental animals Group 3 Not classificable as to its carcinogenicity to humans 499 Evidence is inadequate in humans, and is inadequate or limited (e.g. Chromium (III) in animals compound, coffee)  CFS, 2023  Why to Keep Good Food Safety and Hygiene Standard? Legal requirement Expectation of consumers The advancement of society, consumer lifestyles and demands, improvement of living standard, it is natural that people will expect enhancement in food safety and hygiene Moral responsibility of food business  Merits of Keeping High Standard of Food Hygiene Ensure the quality of food Prevent food poisoning Comply with legal requirement and prevent from prosecution Avoid food wastage Maintain cost effectiveness Protect the reputation of brand Develop good and hygienic working environment to enhance morale and work efficiency Increase sale volume and profit Consequences of Ignoring Food Hygiene Lowering of food quality Lead to food poisoning and arouse food complaints Waste of food and increase operational cost Poor working environment Harborage of pest Lowering of productivity Increased staff turnover Consequences of Ignoring Food Hygiene Non-compliance with legal requirement Being prosecuted, fined or bearing legal cost Victims may sue through civil proceedings Affect business Loss of reputation Low staff morale and work efficiency Customers lose confidence and affect income Business may be winded up  Responsibilities of Management of Food Premises and Food Business Practitioners Management To ensure all food sale is safe and fit for human consumption To improve the standard and nutritional value of food To monitor personal, environmental and food hygiene conditions and keep records of monitoring results To strengthen staff training regarding food safety and assess effectiveness of training and directive courses at regular intervals To keep all food processing records and staff training records and ensure that these records are readily available for inspection To evaluate and verify the effectiveness of the food safety management system at regular time intervals  Responsibilities of Management of Food Premises and Food Business Practitioners Food Business Practitioners (Operators) To prevent contamination and decomposition of food Health and safety of customers should always be prime consideration and regarded as their social responsibility To acquaint the relevant standards and requirements issued by the government/set out in legislation, abide rules and regulation strictly and strengthen hygiene awareness To explore and adopt the most hygiene method in food processing To be careful and cautious during the preparation, production, handling and serving of food To keep on raising the hygienic standard of the food premises  Food Hygiene in Food and Catering Industry Food Handling Process Purchasing of food Food receiving Food storage Food handling Thawing Preparation (such as washing, cutting and seasoning)  Food Hygiene in Food and Catering Industry Food Handling Process Cooking of food Cooling of cooked food Need to Microwave cooking control every Hot holding step to keep Reheating food clean Serving of food and safe Food displaying Transportation of food Food Disposal  Food Hygiene – Purchasing of Foods Food premises should purchased food and food ingredients from reliable suppliers Local food produced by licensed food premises Siu-mei, lo-mei Bread, cakes Frozen confections, milk Sushi, sashimi Meat, meat products  Food Hygiene – Purchasing of Foods Imported from sources approved by the Food and Environmental Hygiene Department Imported meat, game and poultry Imported milk and frozen confections Meat, fish, shellfish and vegetables must be fresh Canned food must not be blown, defective and stored beyond the expiry date Dry ingredients must not be wet by moisture Chilled and frozen commodities on sale must be stored under chilled and frozen conditions Food Hygiene – Food Labels  Food Hygiene – Food Receiving Food products should be inspected as they are received to ensure that the quality of food complied with the product specification laid down by the company which include but not limited to the followings: They are protected from contamination If of potentially hazardous/high risk food items, they are kept at a temperature of: ≤ 4°C or ≥ 60°C The potentially hazardous food intended to be received frozen should be in frozen state when they are accepted For pre-packaged food, the time gap between the date of receiving and “Use By” or “Best Before” date should be sufficient to avoid expiration of stock They are free from pathogens, chemicals and foreign matters contamination and are safe Verified through visual inspection, checking of documents or taking samples for testing)  Food Hygiene – After Receiving Expired raw materials must not be used for preparing food Sub-standard stock should be properly segregated from other food to avoid cross contamination Be careful to open the food package to avoid staples, paper, rubber band and the like from accidentally falling into the food After inspection, arrange proper storage place at appropriate storage temperature as soon as possible (Dangerous temperature zone: between 4°C and 60°C )  Food Hygiene - Storage Raw materials should be stored in a clean and well ventilated area All food stocks must be stored in a clean, well covered or protected environment and at appropriate temperature and humidity Food stocks that require chilled or frozen storage must be done so as soon as it is arrived Stock rotation: “First-in-first-out” principle and to avoid over stocking Food stocks should be stored at least 300mm above the floor and must not be placed on the floor Never use newspaper, dirty paper or colour plastic bags to wrap food  Food Hygiene - Storage Raw and cooked food should be stored separately. If not, they should be stored at separate zone of the freezer or else, cooked food on top and raw food below Fresh food such as meat, fish and shellfish should be stored inside plastic bags or containers Chillers and freezers should have 30% to 40% free space to allow free circulation Freezers should be kept below -18°C and chillers below 4°C Potentially hazardous food should be stored at or below 4°C, or at or above 60oC Food must be stored frozen if they are intended to be stored frozen (preferably stored at -18°C or below)  Food Hygiene – Thawing Place food in a refrigerator or thawing cabinet maintained at 8oC or below Place food in cold running water Use microwave oven Points to notice when thawing Unless thawed food is processed immediately, it should be held at 8oC or below (preferably at 4oC or below) until being used Food thawed in microwave ovens should be cooked immediately Do not repeat freezing and thawing process Thawing of sashimi should be performed inside cold cabinet at temperature below 4 oC Food must not be thawed out at room temperature The quantity of food thawed should best be that need for cooking  Food Hygiene - Preparation Hands Hands should always be clean Avoid touching food with bare hands as far as possible Use of disposable gloves Equipment and utensils Use different colours to distinguish equipment and utensils such as bowls, chopping boards and knives for processing raw and cooked food Use washed and sterilized equipment and utensils Use of utensils appropriately labeled  Food Hygiene - Preparation Equipment and utensils (Cont’d) Process sushi and sashimi in designated area in food room Designated area for processing ready-to eat food e.g. siu-mei and lo-mei should be separated from fish tanks and seafood / poultry washing area Wash and remove internal organ of shellfish Vegetables and fruits must be thoroughly washed and soaked Avoid preparing food too early In preparation of salads, mixed vegetables or other mixed foods, put in other ingredients after those required cooking is cooled down  Food Hygiene - Cooking Food must be cooked thoroughly, especially meat and poultry to kill pathogens When cooking raw animal food, the centre of the food should reach a temperature of at least 75oC for 15 seconds, or an effective time / temperature combination (e.g. 65oC for 10 minutes, 70oC for 2 minutes or 80oC for 6 seconds) Food such as salad and curled vegetables which do not require heating before consumption should be stored under refrigeration immediately after processing Food that has been cooked, and is intended to be kept under refrigeration prior to serving should: Be cooled from 60oC to 20oC within 2 hours or less; and From 20oC to 4oC within 4 hours or less Reduce the volume of the food by dividing it into smaller portions will accelerate cooling Use shallow and broad container Containers should not be stacked up during cooling and there should be a free space in between containers to allow cold air inside the refrigerator/cooling cabinet free circulation  Food Hygiene Microwave cooking Rotated or stirred food throughout or midway during cooking Heated to a temperature of at least 75oC for 15 seconds in all parts of the food Allowed to stand covered for a min. 2 minutes after cooking to obtain temperature equilibrium Hot holding Potentially hazardous food that has been prepared, cooked, and is to be served hot, should be held at a temperature of at least 60oC (Vibrios bacteria multiply faster than other bacteria and can double in number in 10 to 12 minutes at about 30oC) Reheating of food Food that has been previously cooked and cooled, when reheated, should be reheated to 75oC or above as quickly as possible Normally, this reheating time should not exceed 2 hours Food that has been reheated should not be cooled and reheated for a second time  Food Hygiene - Serving Food handlers serving food to consumers should: Wash hands properly and frequently Keep food above 60oC or below 4oC Minimize bare-hand contact with ready-to-eat food If gloves are used to handle ready-to-eat food, they should be of single-use Ice to be used in food and drink should not be handled with bare hands Refresh food displays and avoid mixing old food with fresh batches Do not wipe utensils with aprons, soiled cloths, unclean towels, or hands Do not re-use single-use items, such as straws, paper towels, disposable cups and plates  Food Hygiene - Displaying Operators of food premises should, when displaying food: Ensure the package of pre-packaged food intact and unbroken Cover unpackaged ready-to-eat food with lids or protect it with food guards/sneeze guard Display the food at 4oC or below, or at 60oC or above Ensure the display of frozen food at –18oC or below Siu-mei and lo-mei for sale must be displayed inside approved siu-mei and lo-mei display cabinet/showcase  Food Hygiene - Displaying Operators of food premises should, when displaying food: To display seafood and ready-to-eat separately To maintain hot (at 60oC or above) or cold (at 4oC or below) chain when displaying food, unless it is intended for short time display Sushi and sashimi displayed for sale must be properly wrapped to avoid contamination Sushi and sashimi displayed for immediate consumption in conveyer belt should be properly covered and should not be left on the belt for too long (less than two hours)  Food Hygiene - Transportation Food transportation units (including vehicles, trolleys, boxes, trays, crates, etc.) should be designed, constructed, maintained and used in a manner that protects the food from contamination Food transportation equipment that is intended to be in direct contact with food products should be constructed with non-toxic, easy to clean and maintenance materials, such as stainless steel and food-grade plastic containers During transportation, open food should be carried in enclosed vehicles, packed in covered containers or completely wrapped or packaged to protect it against contamination by dust / dirt / fumes  Food Hygiene - Transportation Food and non-food products transported at the same time in the same vehicle should be adequately separated Vehicles fitted with refrigeration equipment is best used for transporting potentially hazardous food which required storage under refrigeration  Food Hygiene – Food Disposal Food that had been found or suspected to be unsafe or unsuitable for human consumption should be recalled/rejected from the market and disposed of as soon as possible Food wastes should be placed inside covered dustbin and requires frequent emptying