Agriculture Reference
In-Depth Information
more rapid turnover of colonic cells, thus helping maintain healthier tissue. Butyrate
also enhances the health of other cells in the gastrointestinal (GI) tract. Proteins and
peptides affect a number of activities, including many peptides that are angiotensin-
converting enzyme (ACE) inhibitors, helping control plasma cholesterol levels. The
influence of lipids is best exemplified with omega-3 (N-3) fatty acids. The N-3 fatty
acids are reported to enhance neurofunction, lower cholesterol, and reduce chronic
inflammation. The balance between N-3 and N-6 fatty acids is a major concern in
Western diets. Higher levels of N-3 fatty acids in the Mediterranean diet are thought
to be one of the important benefits of the diet.
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Bioactive functional ingredients can come from a variety of sources, including plants,
animals, and microbial sources. Some lipid-based materials, such as phosphatidyl-
choline and sphingolipids, can be recovered from plants, animals, and microbial
sources. The major dietary source of N-3 fatty acids is fish, which provide long-chain
fatty acids. The long-chain fatty acids from fish are eicosapentanenoic acid (C20:5)
and docosahexaenoic acid (C24:6). Plants such as flax and walnut provide α-linolenic
acid (C18:3). Some of the C18:3 fatty acids are converted to the more important C20:5
and C24:6 fatty acids in vivo, but the conversion is limited. Generally, consumption
of higher levels of the longer-chain fatty acids is preferred. Commercially available
eggs are now marketed that provide the longer-chain fatty N-3 fatty acids. These are
produced by feeding the chickens either fish oil or microalgae, which are rich in the
long-chain N-3 fatty acids.
Plants provide the greatest variety of bioactive ingredients. The terpenes and the
phenolics typically are from plant sources. The carbohydrates are also primarily
found in plant-based products. Amino acids, proteins, and peptides can come from
plants, animals, or microbial fermentation. Many interesting bioactive peptides have
been recovered from milk.
Table 13.1 lists bioactive components in foods and provides examples of func-
tional ingredients, their sources, and the purported benefits. Many of the functions
include those that are anticancer, antioxidant, and anti-inflammatory. It is likely that
these categories are all interrelated. Oxidative stress can lead to chronic inflamma-
tion, which can ultimately be seen as cancer or cardiovascular disease.
exAmPles of functIonAl food IngRedIents
There are many functional foods available, and more will emerge as the technology
emerges for understanding how they work. Soy protein, the N-3 fatty acids, and the
antioxidants constitute functional ingredients with significant documentation of the
health benefits they deliver.
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Soy is one of the most widely recognized and accepted functional foods. Soy pro-
tein is consumed in a number of forms, ranging from tofu, to soy milk, to inclusion
