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Section I
Texts for class reading and translation in writing
1. Function and nutrition guide fiber ingredient
selections
Increased dietary fiber content has become a dominant
marketing claim for new product introductions. Because fiber is
not absorbed, products high in fiber are generally much lower in
calories. And because of the ability of certain fiber materials to
reduce serum cholesterol, a product rich in dietary fiber offers
the dual attractions of fat and calorie reduction along with the
potential for improving cardiovascular circulation.
This shift in development effort is further evident at the
ingredient level, where suppliers of traditional vegetables, fruits
and grains have repositioned their products to stress fiber
content and the healthy image this implies.
At the 1988 Food Expo, held June 19-22 in New Orleans,
attendees found twice the number of exhibitors offering dietary
fiber ingredients compared to those exhibiting at Food Expo '87.
Consumer demand for high-fiber foods continues to grow and
extend beyond traditional dietary fiber sources such as breads
and muffins. Over the past four years, extensive research on
fiber and the digestive cycle has clarified our understanding of
various ways in which fiber affects the absorption and digestion
of several significant nutrients found in foods. In addition to the
conventional cereal bran sources, legume hulls, and similar
husk-like fibers, high-fiber ingredients now include prunes,
apples, pears, citrus, several of the tree and plant gums, and
even a fiber obtained as a by-product of tofu production.
Suppliers of traditional fiber ingredients have extended their
product lines to include specially bran blends, or fractionated
products with higher-than-customary levels of protein. (1600)
2. Physical properties of fiber.
Unique physical properties possessed by various sources of fiber
are important in determining certain physiological responses.
Some of these properties and the physiological responses
elicited by specific fiber fractions.
Bacterial degradation, which is relevant to only the
polysaccharide fraction, is the first of these properties. Dietary
fiber cannot be enzymatically degraded in the mammalian small
intestine; it is, however, fermentable to varying degrees of
degradation within the large bowel. The degree of degradation
varies considerably among the polysaccharides. For example,
pectins, mucilages, and gums appear to be completely degraded,
whereas cellulose is only partially broken down.
Furthermore, the extent of breakdown may be related to the
physical structure of the plant: fiber from fruits and vegetables
appear to be more fermentable than that from cereals and grain.
The extent of bacterial degradation has several important
implications: (1) the short-chain fatty acid by-products may
influence the physiological responses to fiber; (2) The
fermentation process can lower the pH of the large bowel and
may affect microbial metabolism. (1400)
Table 5 – Physiological Responses affected by the physical
properties of fiber fractions.
Physical property Fiber fraction Physiological
response
Bactenal degradation
Water-holding
capacity
Polysaccharides
Polysaccharides
with polar groups
Production of short-
chain fatty acids,
flatulence and acidity
Effect on nutrient
absorption fecal
weight and rate of
transit in stomach and
Section I 2. Physical properties of fiber.
Texts for class reading and translation in writing
Unique physical properties possessed by various sources of fiber
are important in determining certain physiological responses.
1. Function and nutrition guide fiber ingredient
Some of these properties and the physiological responses
selections elicited by specific fiber fractions.
Bacterial degradation, which is relevant to only the
Increased dietary fiber content has become a dominant polysaccharide fraction, is the first of these properties. Dietary
marketing claim for new product introductions. Because fiber is fiber cannot be enzymatically degraded in the mammalian small
not absorbed, products high in fiber are generally much lower in intestine; it is, however, fermentable to varying degrees of
calories. And because of the ability of certain fiber materials to degradation within the large bowel. The degree of degradation
reduce serum cholesterol, a product rich in dietary fiber offers varies considerably among the polysaccharides. For example,
the dual attractions of fat and calorie reduction along with the pectins, mucilages, and gums appear to be completely degraded,
potential for improving cardiovascular circulation. whereas cellulose is only partially broken down.
This shift in development effort is further evident at the Furthermore, the extent of breakdown may be related to the
ingredient level, where suppliers of traditional vegetables, fruits physical structure of the plant: fiber from fruits and vegetables
and grains have repositioned their products to stress fiber appear to be more fermentable than that from cereals and grain.
content and the healthy image this implies. The extent of bacterial degradation has several important
At the 1988 Food Expo, held June 19-22 in New Orleans, implications: (1) the short-chain fatty acid by-products may
attendees found twice the number of exhibitors offering dietary influence the physiological responses to fiber; (2) The
fiber ingredients compared to those exhibiting at Food Expo '87. fermentation process can lower the pH of the large bowel and
Consumer demand for high-fiber foods continues to grow and may affect microbial metabolism. (1400)
extend beyond traditional dietary fiber sources such as breads
and muffins. Over the past four years, extensive research on Table 5 – Physiological Responses affected by the physical
fiber and the digestive cycle has clarified our understanding of properties of fiber fractions.
various ways in which fiber affects the absorption and digestion
of several significant nutrients found in foods. In addition to the Physical property Fiber fraction Physiological
conventional cereal bran sources, legume hulls, and similar response
husk-like fibers, high-fiber ingredients now include prunes, Bactenal degradation Polysaccharides Production of short-
apples, pears, citrus, several of the tree and plant gums, and chain fatty acids,
even a fiber obtained as a by-product of tofu production. flatulence and acidity
Suppliers of traditional fiber ingredients have extended their Water-holding Polysaccharides Effect on nutrient
product lines to include specially bran blends, or fractionated capacity with polar groups absorption fecal
products with higher-than-customary levels of protein. (1600) weight and rate of
transit in stomach and
