Bulking and Fat-Replacing Agents - Sweeteners: Nutritional Aspects, Applications, and Production Technology - page 400

resistant starch; oligosaccharides—FOS, oligofructose (OF), PD, and galacto-oligosaccharides; and
soybean oligosaccharides—rafinose and stachyose.
Chitosan is an example of iber of animal origin, derived from the chitin contained in the exo-
skeletons of crustaceans and squid pens, and structurally similar to cellulose (Borderías et al. 2005).
Cereals are the principal source of cellulose, lignin, and hemicelluloses, whereas fruits and veg-
etables are the primary sources of pectin, gums, and mucilage (Slavin et al. 1997; Slavin 2004).
Each polysaccharide is characterized by its sugar residues and by the nature of the bond between
them. The complexity of ibers—their chemical nature, the degree of polymerization (DP), and the
presence of oligosaccharide and polysaccharide—governs their functionality in food systems.
DFs are classiied as soluble or insoluble based on their ability to create stable colloidal disper-
sion when mixed with water (soluble) or not (insoluble). Soluble DFs include pectic substances,
gums, mucilage, and some hemicelluloses, whereas cellulose, other types of hemicelluloses, and
lignin are included in the insoluble fraction (BeMiller 2001). Solubility is related to the structure of
polysaccharides; they can be set regularly (insoluble) or irregularly (soluble) on the backbone or as
side chains. The presence of a substitution group such as COOH or SO 4 − increases solubility, which
is also dependent on the temperature and ionic strength of the system. The solubility of DF is one
of the detriments of their physical and physiological functionalities. Soluble ibers are characterized
by their capacity to increase viscosity in the gut and, thus, reduce the glycemic response and plasma
cholesterol (Abdul-Hamid and Luan 2000). Insoluble ibers are, on the other hand, characterized
by porosity, low density, and ability to increase fecal bulk and decrease intestinal transit (Lunn and
Buttriss 2007). In food processing, the soluble iber has a greater capacity to enhance viscosity, form
gels, act as a surface agent, has no detrimental effect on the organoleptic properties, and, overall, is
easier to handle and incorporate into foods and beverages. Tables 13.3 and 13.4 depict common DFs
based on their solubility and functionality.

table 13.3 Solubility-Based Classiication of Dietary Fibers

property representative

insoluble cellulose

Hot-water soluble agars, aligns (+ca 2+ ), amylose, κ -carrageenan (+k + or ca 2+ ),

gellan, konjac mannan, locust bean gum, low methoxyl-pectins
(+ca 2+ ), and granular starch

Soluble in water at room temperature but not
at high temperature

curldan, hydroxypropylcelluloses, hydroxylpropyl-
methylcelluloses, and methylcellulose

Soluble alginate, amylopectin, carboxymethylcellulose, carrageenans,

dextrins, furcellarans, guar gum, gum arabic, gum tragacanth,
high methoxyl pectin, polydextrose, and xanthan

Source: BeMiller, J. N., Carbohydrate Chemistry for Food Scientists , aacc international, St. paul, MN, 2007.
With permission.

table 13.4 Classiication of Dietary Fibers Based on their physical Functionality

property representative

gelling agars, alginate, carrageenan, curdlan, gellan, gum arabic,

konjac mannan, methylcellulose, pectins, starches, locus bean
gum with κ -carrageenan, and xanthan

Thickening and stabilizing carboxymethylcellulose, gum arabic, gum tragacanth,

hydroxypropylmethylcellulose, modiied starch, and xanthan

Thickening primarily carboxymethylcellulose and guar gum

Fat mimetics β -glucan, cellulose, inulin, polydextrose, psyllium seed gums,

and resistant starch

Source: With kind permission from Springer Science+Business Media: Food Analysis , edited by S. S. Nielsen,
2010, BeMiller, J. N.