Food Sanitation - VM 464 Past Paper PDF

FOOD SANITATION VM 464 (Veterinary Public Health 1) continued... Prof. Helena A. Ngowi Department of Veterinary Medicine and Public Health Sokoine University of Agriculture Morogoro, Tanzania...

FOOD SANITATION VM 464 (Veterinary Public Health 1) continued... Prof. Helena A. Ngowi Department of Veterinary Medicine and Public Health Sokoine University of Agriculture Morogoro, Tanzania 1  Introduction Food – any substance consumed to provide nutritional support for the body of an organism Food sanitation - protection of food from contamination Aim - to ensure safety of food to the consumer All functions and operations must be included in a sanitation program at all stages of food production and distribution Sanitation should be a dynamic and ongoing function 2  Codex General Principles of Food Hygiene (see manual) Codex Alimentarius Commission (CAC) is a body that coordinates food standards at the international level The Codex General Principles of Food Hygiene lay a firm foundation for ensuring food hygiene They follow the entire food chain, highlight key hygiene controls at each stage They recommend an HACCP approach whenever possible to enhance food safety and suitability for consumption 3  Food chain Vehicle emission Crops Processing Agricultural practices Livestock Cooking Retail Landfills Storage Seafood Industrial emissions and effluents 4 Distribution  Codex General Principles of Food Hygiene … These principles are recommended to governments, industry and consumers. But they are not compulsory The application of the General Principles of Food Hygiene and of Good Manufacturing Practices (GMPs) allows the producer to operate within environmental conditions favourable to the production of safe food 5  Codex General Principles of Food Hygiene … Adhering to the General Principles of Food Hygiene will: - Protect consumers from food-borne illness or injury - Provide assurance that food is suitable for consumption - Maintain confidence in internally traded food and - Avoid losses from improper storage and handling 6  I - BASIC ELEMENTS OF A SANITATION PROGRAM AT THE PRIMARY PRODUCTION Primary production - activities undertaken in the farm up to harvesting, storage and transportation Potential hazards associated with the primary production of agricultural products should be identified and controlled 7  Primary Production … Vehicle emission Crops Agricultural products: meat, Processing Agricultural eggs, milk, seafood, grains, … practices Livestock What are possible hazards here? R Landfills Storage Seafood Industrial emissions and effluents FS0101 159 2000 Distribution 8  Strategies to prevent food contamination at the primary production 1. Environmental hygiene - Avoid contaminated areas 2. Hygienic production of food sources - Avoid contamination from air, soil, water, fertilizers, drugs… - Avoid faecal and other contaminants - Take care of plant and animal health 9  Strategies to prevent food contamination at the primary production … 3. Handling, storage and transport - Sort food and food ingredients to segregate unfit ones - Dispose of any rejected material in a hygienic manner - Protect food and ingredients from contaminants e.g pests - Prevent spoilage by controlling favourable conditions 4. Cleaning, maintenance and personnel hygiene - Ensure effective cleaning and maintenance - Maintain appropriate degree of personal hygiene 10  Roles of stakeholder at the primary production Government - Establishing regulatory control programmes - Providing health education programmes (also to consumers) - Provide assurance that food is suitable for human consumption - Maintain confidence in internationally traded foods Industry - Provide safe and suitable food - Provide clear and easily understood information on food - Maintain confidence in internationally traded foods 11  Roles of stakeholder at the primary production … Consumers - Follow relevant instructions about food handling Primary producer (farmer) - Produce suitable raw materials by adhering to good agricultural and good hygienic practices 12  II - BASIC ELEMENTS OF A SANITATION PROGRAM IN FOOD PROCESSING AND HANDLING Food processing industry in developing countries varies widely: Sophisticated modern facilities, to Small operations producing traditional foods for local community Small food processing industries have very limited resources for effective sanitation programmes Nevertheless, there are basic elements of a sanitation programme in any food processing and handling facility 13 Food processing 14 BASIC ELEMENTS OF A SANITATION PROGRAM IN FOOD PROCESSING AND HANDLING … 1. Hygiene and Personnel Practices 2. Premises and surroundings 3. Raw material receiving 4. Storage 5. General cleanliness and housekeeping 6. Equipment construction and maintenance 7. Equipment installation 8. Cleaning and sanitizing equipment 9. Pest control 10. Recall programme 15  Hygiene and Personnel Practices Personnel is the number one consideration because: - It is people who set the rules - It is people who follow the rules - It is people who break the rules of sanitation Personnel training: Appropriate sanitation principles and food handling practices Manufacturing controls Personal hygiene practices 16  Hygiene and Personnel Practices … Personnel should be made aware of: The processing steps and technologies for each product manufactured Where potential problems exist Solutions for the problems to safeguard consumers’ interests 17  Hygiene and Personnel Practices … Hygienic Practices Communicable Diseases/Injuries The following must be restricted from a food-handling area: Persons suffering from, or known carriers of a food-borne disease Persons afflicted with infected wounds, skin infections, sores, etc. Persons with open cuts or wounds unless the injury is completely protected by a secure, waterproof covering 18  Hygiene and Personnel Practices … Hand-washing  All personnel must thoroughly wash hands with soap under warm, running, potable water  Disinfectant hand dips should be used where required  Hands must also be washed after handling contaminated materials and after using toilet facilities  Finger nails should be kept short 19  Hygiene and Personnel Practices … Personal Cleanliness and Conduct  Sanitary protective clothing, hair covering, and footwear must be worn and maintained in a clean, sanitary manner  Objects (i.e. watches, jewelry), tobacco, and gum are not permitted 20  Hygiene and Personnel Practices … Controlled Access/Traffic Restrict personnel and visitor access to specific food- prod handling areas Personnel involved in raw product handling (e.g., farm truck drivers, etc.) must not be allowed in processing or finished product areas Foot baths and hand dips, where required, must be properly maintained and used Color coding of clothing, maintenance and other equipment should be used to clearly identify raw versus processed product operations 21  A teaching chart oooooooo oooooooo oooooooo oooooooo Clean hands, nails and hair Avoid touching ears, nose, lips Wear and hair protective clothing and head cover Cover cuts Pick up cutlery Report illness or and glasses by skin complaints handles or stems 22 oooooooo Poster oooooooo oooooooo oooooooo Always wash your hands before handling food and after handling raw Fish Poultry Meat Vegetables Fruit Eggs After - Using the toilets, blowing your nose, handling pets or refuse 23  Effective personal cleaning and sanitizing Personnel working in food industry should arrive at work while clean and should maintain personal cleanliness and sanitation throughout the period of work Regular cleaning and sanitizing their hands is necessary to avoid acquiring or transmitting diseases Personal cleaning and sanitizing should be done using acceptable procedures and tools 24  Premises and surroundings Outside Surroundings Outside surroundings should be evaluated for sources of contamination (e.g. vermin, bird harborage areas, drainage problems, odour problems, debris, refuse, pollution-smoke, dust, …) Appropriate steps must be taken to contain and control any potential sources of contamination 25  Premises and surroundings … Buildings and Facilities Any food-processing and -handling facility should be cleanable, and prevent entrance or harborage of pests or other sources of contamination Floors, walls, and ceilings should be durable, smooth, and impervious Walls should be light colored and well-joined Floors should be adequately sloped for drainage to trapped outlets Overhead structures should be well situated and constructed Lighting be adequate with properly sealed, safe overhead fixtures Heating and air conditioners be cleanable and prevent contamination 26  Premises and surroundings … Proper drainage and sewage systems Separate raw product functions from processing functions and finished product functions to avoid cross-contamination Washrooms, lunchrooms, and change rooms must have self-closing doors and separated from food processing and handling areas Sufficient numbers of hand-washing sinks, with hot and cold potable water, soap, sanitary hand drying supplies or devices A potable water, steam, and ice supply is imperative for sanitary food-processing and -handling 27  Raw material receiving All elements and operations involved with receiving and storage of ingredients, packaging material, and other incoming materials must be evaluated and monitored to prevent potential contamination of the food product manufactured Incoming materials must be received into an area which is separated from processing areas Only safe, approved raw materials should be received 28  Storage Temperature and humidity of storage rooms for raw materials, ingredients, packaging materials, and food should be maintained and monitored - Avoid storage of food products between 10oC and 60oC (danger zone) - Thaw frozen foods under refrigeration or cold water (not at room temp) - Chemicals must be properly labeled, stored and used in a good manner - Store chemicals in a dry, well-ventilated area which is separate from food-areas 29  General cleanliness and housekeeping All food-processing and handling rooms and other rooms must be maintained in a clean, sanitary manner All custodial brushes and equipment must be in good repair as well as being clean and sanitary E.g. Sanitation in Meat and Poultry Plants 30  Equipment construction and maintenance The overall requirement for design of equipment for food-processing and handling operations is that it should be cleanable and maintained in such a manner as to prevent contamination Food-contact surface equipment should be made according to acceptable standards 31  Equipment installation Adequate space must be provided within and around equipment, and equipment must be accessible for cleaning, sanitizing, maintenance, and inspection Protocols and calibration methods must be established for all equipment that could impact on food safety: thermometers, pH meters, water activity meters, refrigeration controls, scales, recording thermometers, hygrometers,... 32  Cleaning and sanitizing equipment The effectiveness of cleaning and sanitizing programs should thoroughly be evaluated Recommended procedures for cleaning and sanitizing both food-product contact and non-product contact surfaces in specific operations should be followed 33  Pest control An adequate pest control program is necessary for sanitary operation of a food-processing or handling facility Effectiveness of the pest-control program should be verified on a regular frequency Domestic animals such as dogs and cats should also be excluded 34  Recall programme The recall program establishes procedures to be implemented in the event of a product returned from retailers Recalled food products should be well labeled and stored pending for their disposition 35  III – CONTROL OF OPERATIONS Control of food hazards by: Identify any steps in their operations which are critical to the safety of food Implement effective control procedures at those steps; Monitor control procedures to ensure their continuing effectiveness Review control procedures periodically, and whenever the operations change 36  III – CONTROL OF OPERATION … These systems should be applied throughout the food chain to control food hygiene throughout the shelf-life of the product through proper product and process design Control procedures may be simple, for example: checking stock rotation calibrating equipment correctly loading refrigerated display units In some cases a system based on expert advice, and involving documentation, may be appropriate 37  III – CONTROL OF OPERATION … Important aspects: Time and temperature control Specific process steps (e.g., drying, chilling, irradiation, …) Microbiological and other specifications Microbiological cross-contamination Physical and chemical contamination 38 Need a Break? 39  BASIC ELEMENTS OF EQUIPMENT CLEANING AND SANITIZING Cleaning and sanitizing is an important aspect of a sanitation programmme Detailed procedures must be developed for all food-product contact surfaces (equipment, utensils,...) as well as for non-product surfaces (overhead structures, shield, walls, ceilings, lighting devices,...) Cleaning frequency must be clearly defined for each process line (i.e. daily, after production runs, or more often, if necessary) The type of cleaning required must also be identified 40  Cleaning and sanitizing food-contact surfaces Objective - to remove food (nutrients) which bacteria need to grow, and to kill those bacteria which are present The clean, sanitized equipment and surfaces must drain dry and be stored dry so as to prevent bacterial growth The correct order of events for cleaning/sanitizing of food product contact surfaces is: 1. Rinse 2. Clean 3. Rinse 4. Sanitize 41 5. Air drying  Definition of terms Cleaning - the complete removal of food soil (unwanted matter) by physical or chemical (detergents) means Sanitization - the reduction of micro-organisms to levels considered safe from a public health viewpoint Sterilization - the complete destruction and removal of all living micro-organisms Disinfection - the destruction of all vegetative cells (not spores) on inanimate objects 42  Definition of terms … Detergent - a cleansing agent which, acting with water, can remove ‘soil’ or dirt from surfaces Disinfectant or germicide - an agent that destroys bacteria (but not necessarily bacterial spores, which are much more resistant) Antiseptic - a substance which prevents or arrests the growth of organisms either by inhibiting their activity or destroying them Sanitizer - an agent which reduces to acceptable bacteriological standards the number of bacterial contaminants on food contact surfaces 43  Nature of food soils The primary source of soil is from the food product being handled However, minerals from water residue and residues from cleaning compounds contribute to films left on surfaces Microbiological biofilms also contribute to the soil buildup on surfaces Food soils are complex - they contain mixtures of several components No one detergent is capable of removing all types 44  Soil classification Four major classes  Soluble in water (sugars, some starches, most salts)  Soluble in acid (limestone and most mineral deposits)  Soluble in alkali (protein, fat emulsions)  Soluble in water, alkali, or acid (find out) Personnel involved in cleaning equipment should knowledge on the nature of the soil before selecting a detergent or cleaning regime 45  Food soils … The rule of thumb is that acid cleaners dissolve alkaline soils (minerals) and alkaline cleaners dissolve acid soils and food wastes Biofilms usually require cleaners as well as sanitizers with strong oxidizing properties Lubricating greases and oils (insoluble in water, alkali, or acid) can often be melted with hot water or steam, but often leave a residue 46  Food soils … Surfactants can be used to emulsify the residue to make it suspendable in water and flushable Inert soils such as sand, clay, or fine metal can be removed by surfactant-based detergents Carbonized material may require organic solvents Improper use of detergents can actually "set" soils, making them more difficult to remove 47  Chemistry of detergents Detergents and cleaning compounds are usually composed of mixtures of ingredients that interact with soils in several ways:  Physically active ingredients alter physical characteristics such as solubility or colloidal stability  Chemically active ingredients modify soil components to make them more soluble and, thus, easier to remove Some detergents are added with specific enzymes to catalytically react with, and degrade, specific food soil components 48  Detergents … Physically Active Ingredients The primary ones are the surface active compounds (surfactants) A portion of the structure is hydrophilic and a portion is hydrophobic They function in detergents by promoting the physical cleaning actions through: emulsification, penetration, spreading, foaming, and wetting 49  Detergents … Chemically active ingredients Alkaline builders High alkaline detergents (e.g. NaOH and KOH) normally saponify fats foaming soaps Moderately alkaline detergents include Tri-sodium phosphate (TSP) and Na, K, or NH3 salts of phosphates, silicates, or carbonates Acid Builders Organic acids (e.g citric and hydroxyacetic acid) Inorganic acids (e.g phosphoric and nitric acid) 50  Detergents … Water conditioners Used to prevent the build-up of various mineral deposits (water hardness, etc.) by forming soluble complexes with Ca & Mg Examples are sodium tripolyphosphate, tetra-potassium pyrophosphate, organophosphates, polyelectrolytes, sodium gluconate and EDTA Oxidizing agents Example hypochlorite (also a sanitizer) are most often used to clean protein residues 51  Detergents … Enzyme ingredients Enzyme-based detergents, which are amended with enzymes such as amylases and other carbohydrate- degrading enzymes, proteases, and lipases, are more recent developments Fillers Fillers (such as water, NaCl, Na2SO4) add bulk or mass, or dilute dangerous detergent formulations which are difficult to handle Miscellaneous Ingredients Additional ingredients added to detergents may include: corrosion inhibitors, glycol ethers, and butylcellosolve (improve oil, grease, and carbon removal) 52 53  Water chemistry and quality Water comprises ~ 95-99% of cleaning and sanitizing solutions Water functions to: - Carry the detergent or the sanitizer to the surface - Carry soils or contamination from the surface The impurities in water can drastically alter the effectiveness of a detergent or a sanitizer. Thus prior treatment may be necessary Water used for cleaning and sanitizing must be potable and pathogen- free 54  Sanitizing General types of sanitization include: Thermal sanitization Uses hot water or steam for a specified temperature and contact time Chemical sanitization Uses an approved chemical sanitizer at a specified concentration and contact time 55  Sanitizing … Thermal sanitizing Hot-water sanitizing through immersion (small parts, knives, etc.), spray (dishwashers), or circulating systems is commonly used The time required is determined by the temperature of the water and may vary depending on the food to be produced Hot-water sanitization: - Slow process - Can have high energy costs - May be unsafe to employees - Contribute to film formations - Shortens the life of certain equipment or parts 56  Sanitizing … Chemical Sanitizing The regulatory concerns involved with chemical sanitizers are: - Antimicrobial activity or efficacy - Safety of residues on food contact surfaces - Environmental safety It is important to follow regulations that apply for each chemical usage Prior to the sanitization process, all surfaces must be clean and thoroughly rinsed to remove any detergent residue 57  Sanitizing … Factors Affecting Sanitizer Effectiveness Physical factors Surface characteristics – should be clean and free from cracks Exposure time – the longer the better Concentration – optimal concentration is recommended Chemical factors pH Water properties – water impurities inhibit certain sanitizers Inactivators – some present in detergent residues 58  Sanitizing … Types of chemical sanitizers The sanitizing agents commonly used in the food industry belong to four main groups: Halogens Quaternary ammonium compounds Amphoteric compounds Acids and alkalis 59  Sanitizing … Halogens Chlorine In its various forms, is the most commonly used sanitizer in food processing and handling applications Commonly used chlorine compounds - liquid chlorine, hypochlorites, inorganic chloramines, and organic chloramines Recommended usage levels vary depending on the active form of chlorine Iodine (iodophors) Another halogen used as a sanitizer in food industry 60  Sanitizing … Advantages of chlorine compounds: - Broad spectrum germicides - Act on microbial membranes to inhibit cellular enzymes activity - Have activity at low temperature - Relatively cheap - Leave minimal residue or film on surfaces - Less affected by water hardness when compared to other sanitizers The major disadvantage to chlorine compound is corrosiveness to many metal surfaces (especially at higher temperatures) 61  Sanitizing … Quaternary ammonium compounds (QACs) Positively charged cations (e.g savlon) Act on the bacterial membrane function Surfactants, hence possess some detergency Less affected by light soil than are other sanitizers Higher activity at alkaline pH Active and stable over a broad temperature range Leave a residual antimicrobial film (advantage or disadvantage) Effective against bacteria, yeasts, mold, and viruses Essentially bacteriostatic mainly vs Gram+ - not reliable disinfectants 62  Sanitizing … Amphoteric compounds Long chain substituted amino acids or betaines Surface-active Compatible with all other detergents and sanitizers Unaffected by hard water 63  Sanitizing … Acids and alkalis Rarely used in routine cleaning operations Examples - strong mineral acids, caustic alkalis, boric acid, organic benzoic acid Mineral acids and alkalis are corrosive and may be fatal if swallowed 64  Methods for cleaning and sanitizing Manual Mechanical (automated) Both should aim for effectiveness and efficiency Manual vs automated and sanitizing 65  Cleaning and sanitizing non-product surfaces The management should devise an efficient cleaning programme for a food handling premise and its surroundings Cleansing and sanitizing agents used for food product contact surfaces can be used in non-product surfaces The principles of efficient cleaning will involve: Good housekeeping; ‘Dry cleaning’ and Daily and weekly cleaning 66  Cleaning and sanitizing non-product surfaces … A good system of dry cleaning will ensure that the final daily operation is rendered more effective For example, in an animal slaughterhouse ‘dry cleaning’ should commence immediately after the operations have ceased, and should include the whole premises, even to the lairage Detergent followed by sanitizer application, or a combination of both is necessary for actual food processing and handling premises These should be applied under adequate pressures and temperature 67  Cleaning and sanitizing non-product surfaces … The wide variety of processes and surfaces in food handling premises demands diverse cleaning operations Cleaning and sanitization procedures involve: - Removing gross debris from surfaces - Applying a detergent solution - Rinsing with water - Sanitize - (Rinse with water if acid sanitizers are used) - Dry cleaning (put things in order) 68  EVALUATION OF SANITATION EFFECTIVENESS The microbial sampling and enumeration of food contact surfaces is used to evaluate and record the microbial condition of food contact surfaces In order to know that food is being processed safely, the best indicator is the Aerobic Plate Count (APC) of the food Other names for APC, HPC (heterotropic plate count), TPC (total plate count), TVC (total viable count), ACC (aerobic colony count) 69  EVALUATION OF SANITATION EFFECTIVENESS … APC is reported as the total bacterial count per gram (solid foods), equivalent to total bacterial count per mL (liquid foods) Most interpretative guides will describe CFU (colony forming unit), this means the number of microbes found (each bacteria forms a single CFU) The obtained values are compared with acceptable standards 70  EVALUATION OF SANITATION EFFECTIVENESS … In any food handling facility, evaluation of sanitary status of food-contact and non-contact surfaces after sanitation is required to prevent food contamination Samples are taken of surfaces, equipment and other items after cleaning & sanitation steps are performed by the operator to assess effectiveness of process The assessment of surface hygiene is based on the number of microbes found per cm2. Therefore, keep a record of the area sampled to determine the total CFU per cm2 71  EVALUATION OF SANITATION EFFECTIVENESS … (i) Environmental swabs can be used to sample required surfaces Assessment of hygiene is based on the number of microbes found per cm2. Therefore, keep a record of the area sampled to determine the total CFU per cm2 72  EVALUATION OF SANITATION EFFECTIVENESS … (ii) Contact agar plates can be used to sample required surfaces Keep record of the surface area sampled Plate before impression (left) and after impression and incubation (right) 73 (iii) Agar sausages can be used instead of agar plates. Keep record of the surface area sampled  EVALUATION OF SANITATION EFFECTIVENESS … (iv) Small items such as spoons and forks, which are difficult to sample by area, can be rinsed using normal saline or another acceptable sterile fluid, which should the be cultured for microbial counting Microbial load should be expressed in CFU/ML of the fluid 75 EVALUATION OF SANITATION EFFECTIVENESS … It is assumed that after cleaning and sanitization, a surface will be clean, and microbiological results will be low (e.g. less than 5 CFU per cm2) 76  EVALUATION OF SANITATION EFFECTIVENESS … Recommendations 1. Wash hands thoroughly with soap and warm water before and after sample collection and plating 2. Wash, rinse, and sanitize surfaces on which plates are laid before and after plating. Suitable sanitizing solutions are 50 ppm chlorine (1 teaspoon of bleach per gallon of water or 1 ml of bleach per liter of water) 3. Avoid touching the swab head, stem and tip, or plate with your fingers, since your fingers will have transferable skin bacteria 4. Avoid contaminating the plates/swabs head or leaving them 77 exposed for more than 5 minutes  EVALUATION OF SANITATION EFFECTIVENESS … ISO Guidelines for surface sampling and microbial analysis ISO 18593:2004 Microbiology of food and animal feeding stuffs – Horizontal methods for sampling techniques from surfaces using contact plates and swabs Provides a general platform for the critical steps that should be considered in the development of testing procedures It specifies horizontal methods using contact plates or swabs (ISO, 2004). 78  EVALUATION OF SANITATION EFFECTIVENESS … Some key elements of ISO 18593 standards: 1. Moistened swabs should be employed for all sampling of surfaces 2. The solution used to moisten swabs should neutralise any detergent and sanitiser employed 3. Swab moisturizer solution must preserve the integrity of the sample i.e. bacterial numbers should remain constant until the sample collected onto the swab can be evaluated. 4. Wherever possible the size of the area sampled should be greater than 100cm2 5. The analysis of the samples for specific pathogens is achieved by transferring the swabs into an appropriate enrichment broth 6. After enrichment transfer a sample to an appropriate agar plate medium for the target organism being sought 79  EVALUATION OF SANITATION EFFECTIVENESS … Evaluation of the Results from Environmental Microbiological Testing There are various standard levels acceptable for judgment of hygienic statuses for various surfaces E.g., values