1 2 3 HARVESTED OR SLAUGHTERED 4 1. BACTERIA 2. ENZYMES 3. MOULDS 4. YEASTS 5 1. APPEARANCE 2. SMELL 3. TEXTURE 4. TASTE 6 Causes of food spoilage Decomposition enzymes, micro-organisms including bacteria, moulds, yeasts Pest infestation stored product insects, flies feeding and laying eggs on meat Physical damage - freezer burn and oxidation Chemical contamination tainted by strong smelling cleaning materials, perfumed soaps 7 A common kind of food spoilage is caused by MOULD: a fine network of strands called: MYCELIUM 8 9 1. Microbiological hazard 2. Physical hazards 3. Chemical hazards 4. Allergenic hazards 10 SIMPLE RULES FOR PREVENTING BACTERIAL CONTAMINATION: 1. Protect 2. Prevent 3. Destroy 4. Remove 11 People Packing materials Pests Design and structure Maintenance and repairs Wood Glass 12 Cleaning materials Personal grooming products Metal pots and equipment Non-separation of allergenic and allergy free foods Raw materials pesticides, preservatives 13 14 Concerned with preventing spoilage and extending shelf life 15 ATTACK FOOD AFTER SLAUGHTER AND HARVESTING 16 BACTERIA AND ENZYMES ARE MADE INACTIVE BY HIGH AND LOW TEMPERATURES 17 1. Low temperatures 2. High temperatures 3. Dehydration 4. Chemical methods 5. Physical methods 18 affect the metabolic reactions of bacteria: The colder it is, the longer it takes for bacteria to multiply until they become dormant 19 Refrigeration 1oC to 4oC Commercial chilling -1oC to +1oC Blast Chillers cooling hot food to 5oC Freezing -18oC to -23oC inhibits enzyme and bacterial activity Air blast freezing fan assisted freezing air Fluidized bed freezing perforated fan belt on a cushion of freezing air Plate freezing food inserted between metal plates freezing air circulation Cryogenic freezing liquid nitrogen for very quick freezing 20 Cooking (70oC for 2 minutes) Pasteurisation (72oC for 15 seconds) Commercial sterilisation (100oC for 30 minutes milk) Ultra heat treatment (UHT) (132oC for 1 second) Canning (121oC length of time depending on a/w or ph or density of food) Dehydration (reduction of available water sun drying, artificial hot air drying) 21 Salt (absorbs water) Sugar (absorbs water) Pickling (acidifies suitable foods) Nitrates and nitrites (inhibits pathogens) Proprionic acid (mould inhibitor) 22 Vacuum packing (air removed) Modified atmosphere packaging (air modified/reduced) Smoking (some dehydration) 23 24 Nutritional value Appearance Taste Fitness of food 25 BACTERIAL CONTAMINATION BACTERIAL MULTIPLICATION FOOD PESTS CROSS-CONTAMINATION PHYSICAL CONTAMINATION CHEMICAL CONTAMINATION 26 MAKE SURE FOOD IS CHECKED AGAINST SPECIFICATIONS ON DELIVERY: DUE DILIGENCE PRODUCT IDENTIFICATION AND TRACEABILITY 27 LEGAL REQUIREMENTS IN UK: USE BY BEST BEFORE 28 1. Maintains correct levels of stock 2. Older food used first reduces spoilage and wastage 3. Assists pest control 29 Dry food storage Efficient refrigerators Efficient freezers Temperature measuring equipment Recording temperature checks Probe thermometer calibration Cook chill stages Cook freeze stages 30 31 BACTERIAL CONTAMINATION (Staphylococcus aureus) CROSS-CONTAMINATION (salmonella, campylobacter from unwashed hands) CARRIERS (healthy or convalescent) PHYSICAL CONTAMINATION (jewellery) CHEMICAL CONTAMINATION (perfume ) ALLERGENIC CONTAMINATION (careless food handling) 32 TOTALLY COVER PERSONAL CLOTHING AND BE: 1. CLEAN 2. WASHABLE 3. LIGHT COLOURED 4. NO EXTERNAL POCKETS 33 WASH HANDS Before entering food prep. Area Between handling raw and high risk foods After taking a break After going to the toilet After handling waste After using cleaning chemicals After handling known allergens After eating, sneezing, smoking, blowing nose, touching face, hair etc BAD HABITS Using fingers to taste food Using same spoon to taste food Blowing into bags to open them Breathing onto glass or cutlery when drying them Biting nails or sucking fingers 34 Hot water ideal temperature 45oc 50oc Wet hands Use antibacterial liquid soap Rub hands vigorously for about seconds Rinse hands under running warm water Dry hands on clean dry paper towel 35 FOOD HANDLERS .. IMPORTANT TO REDUCE RISK OF CONTAMINATING FOOD WITH PATHOGENIC MICRO-ORGANISMS 36 Septic cuts and spots, boils and skin infections which cannot be adequately covered with water proof dressings FOOD HANDLERS MAY NEED TO BE EXCLUDED FROM FOOD HANDLING DUTIES 37 IF FOOD HANDLERS ARE RECOVERING at home from gastro-intestinal infections, they can in general return to work 48 hours after treatment has ceased. IF FOOD HANDLERS HAVE BEEN CONFIRMED with typhoid or paratyphoid, they can return to work once treatment has ceased and they have produced 6 negative faecal samples