Household Losses 
The best estimate of visible food losses between the retail 
store and actual consumption in households is in terms of 
calories=——15 percent. AS much as two-thirds of this may come 
from fat on meat. Although some of the drippings are reused 
for frying and baking, much is probably discarded along with 
separable fat from roasts, chops, and steaks. Since pure fat 
has over twice as many calories per ounce as carbohydrate or 
protein, losses of fat have a heavy weight in calculation of 
calorie loss. 
Losses in terms of protein and of minerals are lower than for 
calories. According to current estimates, as much as 10 percent 
of the protein that enters the kitchen may not be consumed, and 
7 percent of the calcium. Losses of vitamins because of physi- 
cal loss of foods may average 5 percent. 
All these estimates are rough and are based upon indirect 
evidence. Examples of the more common types of physical losses 
are: Separable fat from meat discarded as plate waste, fat 
drippings discarded, containers broken and foods spilled, foods 
wasted (from children's plates especially), fresh fruits and 
vegetables kept too long and spoiled, sugar left in coffee cups, 
bread becoming stale, toast burned, crusts not eaten, and in- 
sect infestation of cereals, Foods fed to animals may not be 
considered a complete loss, but they account for some of the 
differences between food available for consumption and that 
actually eaten by people. 
Current estimates of invisible chemical losses of four vitsmins 
from cooking and other preparation practices, such as storage of 
leftovers, are as follows: Thiamine, 20 percent; riboflavin, 5 
percent; niacin, 15 percent; and ascorbic acid, 30 percent. 
These estimates are in addition to losses in these vitamins when 
the foods themselves are discarded. 
Losses of vitamins take place from the time foods are harvested 
until they are eaten. Those that occur in the home may also be 
affected by the treatment of foods in marketing, since prepara- 
tion losses are increased by handling that damages the tissue. 
In the kitchen vegetables and fruits may lose nutritive value 
during preparation for cooking or for serving in the raw state. 
The frequently discarded outside leaves of lettuce end broccoli, 
for example, contain more minerals and vitamins than the inner 
parts. Cutting and shredding of vegetables expose new surface 
to the air and allow greater oxidation and consequently loss of 
vitamin C. Losses of vitamins in cooking depend chiefly on the 
volume of water used, the amount of food surface exposed, and 
the length of the cooking period. With larger amounts of water 
more of the water-soluble vitamins and minerals are leached out. 
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