【正文】 山東建筑大學(xué)畢業(yè)設(shè)計 外文文獻(xiàn)及譯文 1 外文文獻(xiàn)： Freezing Meats and Seafood SAFETY OF FROZEN MEATS Wholesome food stored constantly at 0℃ will always be safe. Only the quality suffers with lengthy freezer storage. Freezing preserves food for extended periods because it prevents the growth of microanisms that cause both food spoilage and foodborne illness. Once thawed, however, these microbes can again bee active, multiplying under the right conditions to levels that can lead to foodborne illness. Since they will then grow at about the same rate as microanisms on fresh food, handle thawed items as you would any perishable. Trichina and other parasites can be destroyed by subzero freezing temperatures. However, very strict governmentsupervised conditions must be met. It is not remended to rely on home freezing to destroy trichina. Through cooking will destroy all parasites. NUTRIENT VALUE The freezing process itself does not destroy nutrients. In meat and poultry products, there is little change in nutrient value during freezer storage. PACKAGING Proper packaging helps maintain quality and prevent freezer burn. It is safe to freeze meat or poultry directly in its supermarket wrapping, but this type of wrap is permeable to air. Unless you will be using the food in a month or two, overwrap these packages as you would any food for longterm storage using airtight heavyduty foil, plastic wrap or freezer paper, or place the package inside a plastic bag. Use these materials or airtight freezer containers to repackage family packs into smaller amounts or freeze foods from opened packages. It is not necessary to rinse meat and poultry before freezing. Freeze unopened vacuum packages as is. If you notice that a package has accidentally torn or has opened while food is in the freezer, it is still safe to use。 merely overwrap or rewrap it. 山東建筑大學(xué)畢業(yè)設(shè)計 外文文獻(xiàn)及譯文 2 FREEZER BURN Freezer burn does not make food unsafe, merely dry in spots. It appears as grayishbrown leathery spots and is caused by air reaching the surface of the food. Cut freezerburned portions away either before or after cooking the food. Heavily freezerburned foods may have to be discarded for quality reasons. COLOR CHANGES Color changes can occur in frozen foods. The bright red color of meat as purchased usually turns dark or pale brown depending on its variety. This may be due to lack of oxygen, freezer burn or abnormally long storage. Freezing doesn’t usually cause color changes in poultry. However, the bones and the meat near them can bee dark. Bone darkening results when pigment seeps through the porous bones of young poultry into the surrounding tissues when the poultry meat is frozen and thawed. FREEZE RAPIDLY Freeze food as quickly as possible to maintain its quality. Slow freezing creates large, disruptive ice crystals. During thawing, they damage the cells and cause meat to drip or lose juiciness. Ideally, food 2 inches thick should freeze pletely in about two hours. If your home freezer has a quickfreeze shelf, use it. Never stack packages to be frozen. Instead, spread them out in one layer on the shelves, stacking them only after frozen solid. REFRIGERATOR FREEZERS If a refrigerator freezing partment can’t maintain 0 ℃ , or if the door is opened frequently, use it only for shortterm food storage. Eat those foods as soon as possible for best quality. Use a freestanding freezer set at 0 ℃ or below for longterm storage of frozen foods. Keep a thermometer in your freezing partment or freezer to check the temperature. LENGTH OF TIME 山東建筑大學(xué)畢業(yè)設(shè)計 外文文獻(xiàn)及譯文 3 Because freezing keeps food safe almost indefinitely, remended storage times are for quality only. (See freezer storage chart below.) If a food is not listed on the chart, you may determine its quality after defrosting. First check the odor. Some foods will develop a rancid or off odor when frozen too long and should be discarded. Some may not look pictureperfect or be of high enough quality to serve alone, but may be edible。 use them to make soups or stews. Cook raw food and if you like the taste and texture, use it. FREEZING GAME MEATS Freshly slaughtered meat carcasses or pieces need to be cooled to below 40 ℃ within 24 hours to prevent souring or spoiling. The meat should be chilled to 32 to 36 ℃ . Variety meats (liver, heart or sweetbreads) are ready to be wrapped and frozen after they are cold. For more information, request HGIC 3516, Safe Handling of Wild Game Meats. Quail, dove, duck, pheasant and other game birds should be dressed and gutted as soon as possible after shooting. Cool and clean properly. Remove excess fat on wild ducks and geese since it bees rancid very quickly. Freeze as directed for poultry. For more information, request HGIC 3515, Safe Handling of Wild Game Birds. Note: Do not stuff poultry or game birds before freezing them. During freezing or thawing, food poisoning bacteria could easily grow in the stuffing. Commerciallystuffed frozen poultry is prepared under special safety conditions that cannot be duplicated at home. FREEZING FISH Fish for freezing should be fresh as possible. Wash fish and remove scales by scraping fish gently from tail to head with the dull edge of the knife or spoon. Remove entrails after cutting entire length of belly from vent to head. Remove head by cutting above collarbone. Break backbone over edge of cutting board or table. Remove dorsal or large back fin by cutting flesh along each side and pulling fin out. Do not trim fins with shears or a knife because bones will be left at the base of the fin. Wash fish thoroughly in cold running water. 山東建筑大學(xué)畢業(yè)設(shè)計 外文文獻(xiàn)及譯文 4 Fish is now dressed or pan dressed, depending on size. Large fish should be cut into steaks or fillets for easier cooking. For steaks, cut fish crosswise into 1 inch thick steaks. For fille