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Carbohydrates are major components of foods, accounting for more
than 90% of the dry matter of fruits and vegetables and providing for
70-80% of human caloric intake worldwide (BeMiller and Huber 2008).
Thus, from a quantitative perspective alone, carbohydrates warrant the
attention of food chemists. From the standpoint of food quality carbo-
hydrates are multifunctional. Sugars are the major source, as well as our
reference point, for sweetness. Although carbohydrates are described as
being odorless, the volatile reaction products from the Maillard reaction,
Strecker degradation, and carmelization reactions can provide desirable,
undesirable, or neutral flavor compounds. And, although carbohydrates
are colorless, sugars participate in Maillard and carmelization reactions to
produce desirable and undesirable brown colors. Cellulose, hemicellulose,
pectin, and starch are the structural components of plants that are largely
responsible for the textural characteristics of fruits and vegetables. Starch
and starch derivatives and various hydrocolloids isolated from plants,
seaweed, and microbial sources are used as thickeners, gelling agents,
bodying agents, and stabilizers in foods. When it comes to nutrition, a
sizable portion of the lay public view carbohydrates in a bad light. Car-
bohydrates are often blamed for health issues such as obesity, diabetes,
and dental caries. It should be realized that carbohydrates are, or should
be, the principal source of energy in our diet. After all, we evolved as a
species to efficiently use carbohydrates that can be converted to glucose
for our body's fuel. Good nutrition is based on the consumption of the
appropriate carbohydrates in the right amounts in balance with other
nutrients. It is widely accepted that consumption of various forms of com-
plex carbohydrate can reduce the risk of diabetes, coronary heart disease,
diverticulitus, and colon cancer. For peak athletic performance, the advice
of professional nutritionists will emphasize consumption of the appropri-
ate carbohydrates, in the appropriate amounts, at the appropriate time.
Although the percentage of carbohydrates contributing to caloric intake in
the United States is highly variable, the average is considerably less than
70%. Dietary recommendations call for increased consumption of fruits
and vegetables and a greater proportion of complex carbohydrate (Walker
and Reamy 2009; WHO 2010). |