Agriculture Reference
In-Depth Information
brownish color. Sterilized milk is not really sterile but can be kept for several weeks
without refrigeration. Ultra-high-temperature (UHT) treatment involves heating the
raw milk fluid to 135 to 1508C for only 2 seconds before packaging in sterile containers.
UHT milk can be kept for several months without refrigeration. The final product of all
treatment processes may be sold in metal cans, glass bottles, plastic bottles, plastic
bags, or paper boxes.
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Because of the highly perishable nature of liquid milk, most cultures have devel-
oped products made from fermented forms of milk. These usually involve conversion
of lactose to lactic acid, which halts further fermentation and acts to protect the milk
from spoilage. These milk products may be classified as fermented milk, butter and
ghee, and cheese.
Typical fermented milk products include yogurt, sour buttermilk, and curds (cottage
cheese). Each culture has local variants on this process with unique names and flavors. In
most cultures butter is made by churning fermented milk, as opposed to churning whole
milk in European cultures. Ghee is a cooking product made in Asia and parts of Africa by
heating unsalted butter from 110 to 1208C to remove moisture. After cooling, the remain-
ing mixture is filtered through muslin cloth and bottled for sale.
The main purpose of cheese making is to preserve the milk over long periods of
time without spoilage. Cheese is made by precipitating casein from whole milk by
the addition of specific enzymes. Cheese is produced by nearly all cultures in the
world, with the possible exception of some countries in southern and eastern Africa.
The variety of cheese types is extensive.
Meat.
It is interesting to note that with some animals the meat has a different
English name than the animal. For example, chicken meat is called “chicken” while
meat of a cow is called “beef.” Similarly, calf meat is called “veal” and pig meat is
called “pork.” One theory holds that the names of the animals came from Anglo-Saxon
farmers who used English names but that the people who cooked and served the meat
used Norman French names. Therefore beef is related to the French boeuf and veal is
derived from veau.
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Meat and meat products are more susceptible to bacterial contamination and degra-
dation than milk products. This is often due to the unsanitary conditions of harvest and
less than ideal methods of transport and handling. In many northern climates handling
of meat is done under refrigerated conditions in the summer months and under naturally
cold conditions in the winter. Tropical areas have no cold season, and rural areas often
lack refrigeration for storage of meat products. One of the reasons for this lack of facili-
ties is the low per capita meat consumption in many developing countries. Typically, a
family in Africa or parts of Asia will consume less than 20 percent of the amount of
meat products as a North American. With less demand, it is not surprising to see less
effort in the marketing of meat products.
While meat products in North America are prepared and packaged under carefully
controlled conditions, many rural butchers harvest animals and sell the meat in a local
market the same day. These meat products are also consumed the same or the next day.
Even where homes have refrigerators, the level of contamination is high enough to
prevent storage for more than 1 to 2 days. In contrast, meat products sold in
