Reseñas

Chapter 1

The Importance of Fats
The importance of fats for humans, animals and plants lies in their high content of
energy, which permits the greatest possible storage of energy in the smallest possible amount of food substance. In addition, fats allow humans and animals to consume fat-soluble vitamins and provide them with essential fatty acids, that is, those
indispensable fatty acidsthat their bodies are unable to synthesize themselves.
Fats are omnipresent in nature, although in the most diverse quantities. In the
human body, they play a decisive role as well, beginning with the nutrition of the
infant with breast milk. During the first 5 d, breast milk contains an average of
29.5% fat; from d 6 through 10, the amount is 35.2% and later 45.4% (Macy
1949). In the course oflife, a human living in the industrial world satisfies an average of >40% of energy demand with fat. Metabolized in the human body, fats yield
38 kj/g of energy (9 kcal/g). In this exothermic reaction, -2000 mL of oxygen per
gram of fat is consumed and -1400 mL of carbon dioxide is produced (Peters and
van Slyke 1946). In addition to -63 ton of water, 0.5 ton of alcohol, 8 ton of carbohydratesand 2 ton of proteins, humans consume -3 ton of fat during their lives.
The efficiency of fat as foodstuff is very high, because the fat contained in
food is almost completely reabsorbed by the body; in the feces (in the course of
one’s life -5 ton, plus 30 ton of urine) only 3.3% of lipids can be found (Pimparkar
1961). Thus, fats play an indispensable part in nutrition as supplier ofenergy,
source of compounds that the body cannot synthesize by itself, and carrier of vital
substances. Fats cannot be replaced by other substances. Apart from this physiological aspect, they are excellent carriers of flavors, and dishes prepared with fats
are much tastier than others.
Fats also provide a smooth, creamy consistency to many dishes, which translates into a good mouth-feel. Thisexplains in part why the consumption of fat is
still very high today, even though the segment of the population performing hard
labor has diminished greatly compared with the past, rendering a very high supply
of calories no longer necessary (see also Chapter 1.4).
The improvement in flavor, in particular, is certainly the reason why fats and oils
have been appreciated for a long time. However,only since the beginning of the present century has it been possible in the industrial nations to provide the population
with sufficient quantities of fat at reasonable prices (see Chapter 1.3). Because of t his
increasing importance of fats and oils, governments have intervened to a great extent
in their production and distribution in the last 100 years (see Chapter 1.5). European
foodlegislation, in particular, has often been marked by protectionist objectives.
The importance of fats and oils to the global economy (Chapter 1.3) becomes
clear when considering the amount of oilseed and fruit grown worldwide. In 1995,
-60 million ton of palm fruit and -1 1 million ton of olives as well as >200 million
ton of oilseeds were harvested. From these amounts, >90 million ton of oils andfats were derived. Many countries are trying to enlarge their shares in the interna-

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Fats and Oils Handbook

tional market, a strategy that is usually to the disadvmtage of others and leads to
defensive measures. National interests play a part here. For example, 10 years ago,
the European Union began to promote the cultivation of sunflowers and rape in the
area of the Community. Asimultaneous attempt to stabilize the Community’s buda
get deficit by introducing a t x on fat caused the U S . to fear for its soy exports,
resulting in a threat of trade obstructions aimed at the European automobile industry. The confrontation was averted in 1987, but it will reappear again and again,
ax
unless the issue of a t on fat is buried for good.
In addition to the importance of oils...