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Published byRuth Stephens Modified over 9 years ago
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3 HARVESTED OR SLAUGHTERED
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4 1. BACTERIA 2. ENZYMES 3. MOULDS 4. YEASTS
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5 1. APPEARANCE 2. SMELL 3. TEXTURE 4. TASTE
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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
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7 A common kind of food spoilage is caused by MOULD: a fine network of strands called: MYCELIUM
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9 1. Microbiological hazard 2. Physical hazards 3. Chemical hazards 4. Allergenic hazards
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10 SIMPLE RULES FOR PREVENTING BACTERIAL CONTAMINATION: 1. Protect 2. Prevent 3. Destroy 4. Remove
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11 People Packing materials Pests Design and structure Maintenance and repairs Wood Glass
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12 Cleaning materials Personal grooming products Metal pots and equipment Non-separation of allergenic and allergy free foods Raw materials – pesticides, preservatives
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14 Concerned with preventing spoilage and extending shelf life
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15 “ATTACK” FOOD AFTER SLAUGHTER AND HARVESTING
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16 BACTERIA AND ENZYMES ARE MADE INACTIVE BY HIGH AND LOW TEMPERATURES
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17 1. Low temperatures 2. High temperatures 3. Dehydration 4. Chemical methods 5. Physical methods
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18 affect the metabolic reactions of bacteria: The colder it is, the longer it takes for bacteria to multiply – until they become dormant
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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
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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)
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21 Salt (absorbs water) Sugar (absorbs water) Pickling (acidifies suitable foods) Nitrates and nitrites (inhibits pathogens) Proprionic acid (mould inhibitor)
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22 Vacuum packing (air removed) Modified atmosphere packaging (air modified/reduced) Smoking (some dehydration)
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24 Nutritional value Appearance Taste Fitness of food
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25 BACTERIAL CONTAMINATION BACTERIAL MULTIPLICATION FOOD PESTS CROSS-CONTAMINATION PHYSICAL CONTAMINATION CHEMICAL CONTAMINATION
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26 MAKE SURE FOOD IS CHECKED AGAINST SPECIFICATIONS ON DELIVERY: “DUE DILIGENCE” PRODUCT IDENTIFICATION AND TRACEABILITY
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27 LEGAL REQUIREMENTS IN UK: USE BY BEST BEFORE
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28 1. Maintains correct levels of stock 2. Older food used first – reduces spoilage and wastage 3. Assists pest control
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29 Dry food storage Efficient refrigerators Efficient freezers Temperature measuring equipment Recording temperature checks Probe thermometer calibration Cook – chill stages Cook – freeze stages
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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)
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32 TOTALLY COVER PERSONAL CLOTHING AND BE: 1. CLEAN 2. WASHABLE 3. LIGHT COLOURED 4. NO EXTERNAL POCKETS
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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
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34 Hot water – ideal temperature 45oc – 50oc Wet hands Use antibacterial liquid soap Rub hands vigorously for about 15-20 seconds Rinse hands under running warm water Dry hands on clean dry paper towel
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35 FOOD HANDLERS ….. IMPORTANT TO REDUCE RISK OF CONTAMINATING FOOD WITH PATHOGENIC MICRO-ORGANISMS
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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
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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
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