1.5.3 Research.docx

Food handling and preparation ============================= We face two major sanitation problems when handling and preparing food. The first is cross contamination, defined in the previous session. The second problem is that, while we are working on it, food is usually at a temperature between 5°...

Food handling and preparation ============================= We face two major sanitation problems when handling and preparing food. The first is cross contamination, defined in the previous session. The second problem is that, while we are working on it, food is usually at a temperature between 5°C to 57°C (41°F and 135°F), or in the Food Danger Zone. The lag phase of bacteria growth (p. 18) helps us a little but, to be safe, we must keep foods out of the danger zone whenever possible. 1. Start with clean, wholesome foods from reputable purveyors. Whenever applicable, buy government-inspected meats, poultry, fish, dairy, and egg products. 2. Handle foods as little as possible. Use tongs, spatulas, or other utensils instead of hands when practical. 3. Use clean, sanitized equipment and worktables. 4. Clean and sanitize cutting surfaces and equipment after handling raw poultry, meat, fish, or eggs and before working on another food. 5. Place only food items and sanitary knives or other tools on cutting boards. Do not set food containers, tool boxes, or recipe books, for example, on cutting boards, as the bottoms of these items are not likely to be sanitary. 6. Clean as you go. Don't wait until the end of the workday. Keep clean cloths and sanitizing solution handy at your workstation and use them often. 7. Wash raw fruits and vegetables thoroughly. 8. When bringing foods out of refrigeration, do not bring out more than you can process in 1 hour. 9. Keep foods covered unless in immediate use. 10. Limit the time that foods spend in the Food Danger Zone. Observe the four-hour rule (p. 26). 11. Cook foods to minimum internal cooking temperatures (see next section). 12. Taste foods properly. With a ladle or other serving implement, transfer a small amount of the food to a small dish. Then taste this sample using a clean spoon. After tasting, do not use either the dish or the spoon again. Send them to the warewashing station or, if using disposables, discard them. 13. Boil leftover gravies, sauces, soups, and vegetables before serving. 14. Don't mix leftovers with freshly prepared foods. 15. Chill all ingredients for protein salads and potato salads before combining. 16. Cool and chill foods quickly and correctly, as explained in the following section. Chill custards, cream fillings, and other hazardous foods as quickly as possible by pouring them into shallow, sanitized pans, covering them, and refrigerating. Do not stack the pans. Minimum Internal Cooking Temperatures ------------------------------------- The minimum internal cooking temperature is the internal temperature for a given food product at which microorganisms are killed. The product must be held at that temperature for a specified period for the food to be considered safe. See Table 2.5. Be sure to measure internal temperatures in at least two or three places, always inserting the thermometer into the thickest part of the food. Use sanitary thermometers that are accurate to within 2°F or 1°C. Cooling Procedures ------------------ If cooked foods are not to be served immediately or kept hot for service, they must be cooled quickly so they do not spend too much time in the Food Danger Zone. The rate at which foods cool depends on their total volume in relation to how much surface area they have to transfer heat away. In other words, a large batch of food cools more slowly because it has less surface area per unit of volume. One of the hazards of cooking foods in large volumes is cooling them so slowly they spend too much time in the Food Danger Zone. To help gauge the time you may safely take to cool large volumes of food, use either the two-stage cooling method or the one-stage cooling method. For the two-stage cooling method, cool foods from 135°F (57°C) to 70°F (21°C) in no more than 2 hours, and then from 70°F (21°C) to below 41°F (5°C) within an additional 4 hours, for a total cooling time of no more than 6 hours. The temperature range between 70°F (21°C) and 125°F (52°C) is the most dangerous part of the Food Danger Zone. This method ensures the food spends a minimum of time in that temperature range. If food has not cooled to 70°F (21°C) within 2 hours, it must be reheated to 165°F (74°C) and held at that temperature at least 15 seconds and then cooled again. For the one-stage cooling method, cool foods to below 41°F (5°C) in no more than 4 hours. If the food does not reach this temperature in 4 hours, it must be reheated to 165°F (74°C) and held at that temperature at least 15 seconds and then cooled again. The onestage method should be used if the item was made from potentially hazardous foods that were at room temperature when preparation was begun. Temperature control ------------------- Temperature plays a very important role in food safety. The temperatures between 5 °C and 63°C are referred to as the danger zone because this is the temperature range where it is possible for bacteria to multiply, with most rapid activity at around 37°C. When cooking food, take it through the danger zone quickly. Most food should be cooked to 75°C to kill bacteria. When cooling food, cool it quickly (within 90 minutes) so that it is not in the danger zone longer than necessary. Electronic temperature probes can be used to measure the temperature in the centre of both hot and cold food. They are also good for recording the temperature of deliveries and checking food temperatures in fridges. Make sure the probe is clean and disinfected before use (disposable disinfectant wipes are useful for this). Place the probe into the centre of the food, making sure it is not touching bone or the cooking container. The running temperature of refrigerators, freezers and chill cabinets should be checked and recorded at least once a day. Refrigerators and chill cabinets should be below 5°C and freezers below --18°C. Systems are now available to log temperatures of all fridges, freezers and display cabinets in a business. Temperatures are recorded and sent to a central computer several times a day. These can then be printed or stored electronically as part of due diligence record keeping. Units not running at correct temperatures will be highlighted. Preparation ----------- Monitor the time that food spends at kitchen temperatures and keep this to a minimum. When preparing large amounts, do so in batches, keeping the majority of the food refrigerated until it is needed. It is important that the core temperature of food does not go above 8 °C. If you need to defrost frozen food, place it in a deep tray, cover with film and label it with what the item is and the date when defrosting was started. This is best done in a specific thawing cabinet. Alternatively, place at the bottom of the fridge where thawing liquid cannot drip on to anything else. Defrost food completely (no ice crystals on any part); once thawed, the item should remain at refrigerator temperatures and then be cooked thoroughly within 12 hours. Cooking ------- Cooking food to a core temperature of 75°C for two minutes will kill most bacteria and these temperatures are important, especially where large amounts are being cooked or the consumers are in the high-risk categories. However, some dishes on hotel and restaurant menus may be cooked to a lower temperature than this according to individual dish and customer requirements. Lower temperatures -- but no lower than 63°C -- can be used when a whole piece of meat such as a steak is cooked. Always cook to the higher recommended temperature when meat has been boned/rolled or minced, or where the food is part of a made-up dish such as fishcakes or fish pie. The cooking temperature needs to be appropriate to ensure all spores are killed. Where customers choose dishes cooked to temperatures lower than those recommended, a warning is sometimes put on the menu stating that customers eat these at their own risk. Chilling -------- If food is being cooled/chilled to serve cold or for reheating at a later time, it must be cooled to 8°C within 90 minutes. This will help prevent multiplication of any bacteria that may be present and avoid any possible problem with spores. The best way to do this is in a blast chiller. Freezing -------- If food is being frozen to be reheated at a later time, it must be frozen in a proper blast freezer. Do not put it into a normal freezer as it will not freeze quickly enough and can raise the freezer temperature. This can damage food already in the freezer. The food must be cooled to --18°C within 4 hours. Reheating --------- If reheating previously cooked food, reheat to at least 75°C (the recommendation is 82°C in Scotland). The temperature in the centre of the food must be maintained for at least two minutes and reheating must only be done once. Holding for service, serving and transporting --------------------------------------------- Cooked food being held for service, served or transported must be kept above 63 °C for hot food or below 5°C for cold food. Food spoilage ------------- This is food that has spoiled or 'gone off'. Unlike contamination with bacteria it can usually be detected by sight, smell, taste or texture. Signs of spoilage include mould; slimy, over-wet or over-dry food; a sour smell or taste; discoloured and wrinkled food; or other texture changes. It is caused by the natural breakdown of the food by spoilage organisms such as spoilage bacteria, enzymes, moulds and yeasts which, in some cases, may not be harmful themselves but cause the food to deteriorate. Spoilage may also be caused by poor storage, poor handling or by contamination of the food. Food spoilage can account for a significant amount of unnecessary waste in a business; it should not happen if food stock is being managed and stored properly. Any food that has spoiled or is out of date must be reported to the supervisor/line manager then disposed of appropriately and marked 'not for human consumption'. It should be separated from general waste and be disposed of away from food storage areas.