Bulking and Fat-Replacing Agents - Sweeteners: Nutritional Aspects, Applications, and Production Technology - page 399

carbohydrate-based fat mimetics allows for the incorporation of air bubbles and the structural stabi-
lization of a food matrix (Lee et al. 2005), which may compensate for the volume and textural loss
of reduced-fat foods. In addition, most iber-based fat replacers in solutions exhibit shear-thinning
low behaviors that are known to provide a light and nonslimy mouthfeel to food products (Burkus
and Temelli 2000). This chapter describes some carbohydrates, also considered dietary ibers (DFs),
commonly used as either bulking agents or fat mimetics.

13.2 DIetarY FIBerS

The substantial scientiic importance of DFs was realized over 20 years ago and has been grow-
ing steadily. Foods rich in DFs such as nuts, whole-grain lour, fruits, and vegetables have been
associated with decreased blood cholesterol, lower insulin release, increased stool bulk, improved
laxation, and weight management. Epidemiological studies have correlated high consumption of
DFs with lower incidence of certain diseases such as cardiovascular disease and cancer of the colon
and rectum (Park et al. 2005; Mann and Cummings 2009). Hipsley (1953) was the irst to deine
DF as a nondigestible constituent of the plant cell wall. The most frequent deinition has come from
Trowell et al. (1985), who stated that, “Dietary ibres consist of remnants of plant cells resistant to
hydrolysis (digestion) by the alimentary enzymes of man,” whose components are hemicellulose,
cellulose, lignin, oligosaccharides, pectins, gums, and waxes. The American Association of Cereal
Chemists (AACC 2001) deined DF as the edible parts of a plant or analogous carbohydrates that are
resistant to digestion and absorption in the human small intestine with complete or partial fermenta-
tion in the large intestine. A panel on the deinition of DF (Institute of Medicine 2002) deined the
DF complex to include DFs consisting of nondigestible carbohydrates and lignin, which are intrinsic
and intact in plants, functional ibers consisting of isolated, nondigestible carbohydrates, which have
beneicial physiological effects in humans, and total iber as the sum of DF and functional iber
(Rodriguez et al. 2006).
DF is usually divided into four main categories: (1) total nonstarch polysaccharides (NSPs),
which can further be categorized into insoluble and soluble NSPs; (2) resistant starch; (3) fruc-
tooligosaccharides (FOS); and (4) inulin and lignin. The energy released by fermentation varies
with the source, with the most frequently cited value being 8.2 kJ/g (Wisker and Feldheim 1990,
1992). These carbohydrates can be classiied into a number of ways: based on the structure (linear
or branched), based on the source (plant, animal, or synthetic), and solubility (soluble or insolu-
ble; BeMiller 2001). The chemical nature of DFs is complex, because they constitute a mixture
of chemical entities, as shown by their classiication into nondigestible carbohydrates, lignin, and
other associated substances of plant origin, ibers of animal origin, and modiied or synthetic non-
digestible carbohydrate polymers (Table 13.2). Nondigestible carbohydrates constitute the follow-
ing: polysaccharides—cellulose, β-glucan, hemicelluloses, gums, mucilage, pectin, inulin, and

table 13.2 Classiication of Dietary Fibers and Some Main representatives

Class of Dietary Fiber representatives

Nonstarch polysaccharides and resistant
oligosaccharides

cellulose, hemicelluloses, arabinoxylans, arabinogalactans,
polyfructose, inulin, oligofructans, galactooligosaccharides,
mucilages, and pectins

carbohydrate analogues indigestible dextrins, resistant maltodextrins, synthesizes

carbohydrate compounds, polydextrose, methyl cellulose, and
resistant starch

lignin complexes Waxes, phytate, cutin, saponins, suberin, and tannins

Source: deVries, J. W., Proc. Nutr. Soc. 62, 37-43, 2004. With permission.