1、2430 单词， 12000 英文字符， 3940 汉字 出处 : Jeremiah L E. Freezing effects of food quality.J. Freezing Effects of Food Quality, 2006. 外文文献： 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. Freezi
2、ng preserves food for extended periods because it prevents the growth of microorganisms that cause both food spoilage and foodborne illness. Once thawed, however, these microbes can again become active, multiplying under the right conditions to levels that can lead to foodborne illness. Since they w
3、ill then grow at about the same rate as microorganisms on fresh food, handle thawed items as you would any perishable. Trichina and other parasites can be destroyed by sub-zero freezing temperatures. However, very strict government-supervised conditions must be met. It is not recommended to rely on
4、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 p
5、revent 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 long-term storage using airtight heavy-duty foil, plastic
6、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
7、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. FREEZER BURN Freezer burn does not make food unsafe, merely dry in spots. It appears as grayish-brown leathery spots and is caused by air reaching
8、 the surface of the food. Cut freezer-burned portions away either before or after cooking the food. Heavily freezer-burned 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 b
9、rown depending on its variety. This may be due to lack of oxygen, freezer burn or abnormally long storage. Freezing doesnt usually cause color changes in poultry. However, the bones and the meat near them can become dark. Bone darkening results when pigment seeps through the porous bones of young po
10、ultry 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, foo
11、d 2 inches thick should freeze completely in about two hours. If your home freezer has a quick-freeze 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 compar
12、tment cant maintain 0 , or if the door is opened frequently, use it only for short-term food storage. Eat those foods as soon as possible for best quality. Use a free-standing freezer set at 0 or below for long-term storage of frozen foods. Keep a thermometer in your freezing compartment or freezer
13、to check the temperature. LENGTH OF TIME Because freezing keeps food safe almost indefinitely, recommended 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 wil
14、l develop a rancid or off odor when frozen too long and should be discarded. Some may not look picture-perfect 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 sla
15、ughtered 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, Saf
16、e 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 becomes rancid very quickly. Freeze as directed for poultry. For more information, request HGIC 3515, Safe Handling of Wild Game Birds.
