Scientists estimate that there are between 22000 to 27000 polar bears. Its closest relative is the brown bear. Adult male polar bears are 2,5 to 3 meters tall. They weigh 250 to 770 kilograms. Adult female bears are smaller. They are about 1,8 to 2,5 meters tall and weigh 90 to 320 kilograms. Polar bears usually eat seals usually the ringed seasl, but sometimes the bearded seals. When hunting is good, polar bears will typically eat only the fat and leave the rest of the carcass for scavengers including arctic foxes, ravens, and younger bears. Polar bears also sometimes kill and eat both walrus and beluga whales. They have even hunted short-legged reindeer and sometimes even birds and bird eggs. Polar bears are top of the food chain in the Arctic. They help to keep the balance of nature by preventing an overpopulation of seals. In the wild, polar bears live an average of 15 to 18 years, although biologists have tagged a few bears who are 30 years old
ation, but this is usually transient, since the and cured meats (Parry 1993). An example metmyoglobin is reduced to myoglobin, of vacuum packed meat is presented in Figure usually within four days, as anoxic condi- 13.4. The first significant commercial appli- tions are established and maintained (Gill cation was for vacuum packaging of whole and Jones 1994). However, O2 scavengers turkeys using rubber stretch bags (Purdue may be used in CAP systems to prevent the 1997). VP extends the storage life of chilled formation of metmyoglobin, if very low meats by maintaining an O2 deficient envi- levels of O2 are accidentally incorporated ronment within the pack (Bell et al. 1995). during pack filling. Buys (2004) found that Vacuum packs are comprised of evacuated
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