Polysaccharides, flaxseed

D (+) Galactose is a constituent of numerous polysaccharides It is best obtained by acid hydrolysis of lactose (milk sugar) a disaccharide of d glucose and d galactose L (—) Galactose also occurs naturally and can be prepared by hydrolysis of flaxseed gum and agar The principal source of d (+) mannose is hydrolysis of the polysaccharide of the ivory nut a large nut like seed obtained from a South American palm... 

Flax fiber widths, image analysis of, 11 615 Flaxseed polysaccharide... 

Flaxseed mucilage, associated with hull of flaxseed, is a gum-like material and composed of acidic and neutral polysaccharides. The neutral fraction of flaxseed mainly contains xylose (62.8%), whereas the acidic fraction of flaxseed is comprised mainly of rhamnose (54.5%), followed by galactose (23.4%) (Cui et al., 1994a). A study by Warrand et al. (2005) found that the neutral monosaccharides were a mixture of three major families of polymers, arabinoxylans with a constant A/X ratio of 0.24, and various amount of galactose and fucose residues in the side chains. Acidic hydrolysis yields xylose, galactose, arabinose, rhamnose, galacturonic acid, fucose, and glucose (BeMiller, 1973 Erskine and Jones, 1957). 

Cui and Mazza (1996) reported that neutral polysaccharides have a larger molecular size than acidic polysaccharides and flaxseed gum showed superior moisture retention properties compared to carboxymethylcellulose, Arabic, guar, and xanthan gums. Acidic polysaccharides show more shear... 

Flaxseed powder and oat bran were utilized as a fat replacer in cake without any detrimental effects (Lee et al., 2004b). Flaxseed significantly decreased viscosity at 20% however, an increase in cake volume was observed, potentially due to the high lipid content which served as a shortening in the presence of nonstarch polysaccharides. However, more data are required to explain the observed phenomenon. Flaxseed powder addition significantly (p < 0.05) darkened crumb color and increased yellowness values. Results indicated that flaxseed was an acceptable additive when used with Nutrim oat bran. 

Oomah, B.D., Kenaschuk, E.O., Cui, W., and Mazza, G. 1995b. Variation in the composition of water-soluble polysaccharides in flaxseed. J. Agric. Food Chem. 43, 1484—1488. 

In structural studies, flaxseed polysaccharides were separated into neutral and acidic fractions by use of cetyldimethylammonium bromide. Data from methylation analysis66 showed that the first fraction yielded only methylated D-xylose derivatives, with a high amount of 2,3,4-tri-O-methyl-D-xylose... 

Fig. 19.—Elution patterns of anti-xylose (A) and anti-galacturonic acid (B) antibodies from adsorbents with xylose ligands and with flaxseed polysaccharide ligand. Elution with D-xylose and with D-galacturonic acid indicated by arrows.

Many other polysaccharides have been investigated as gums, but have not reached the status of commercial viability. Among these are polysaccharides from chia seeds [93], corn hull (corn fiber), flaxseed [93], okra [93], and tamarind seeds [93] (used in India). 

Occurs in agar-agar, chagual gum, red algae, flaxseed mucilage and a snail galactan. The L-galactose obt. from the hydrolysates of these polysaccharides can be freed from the enantiomer present by fermentation of the D-form. 

Preparation of protein ingredients from seed meal is also possible since it contains about 26% of crude protein. In addition to the traditional uses of seed meal, recovery of its protein fraction, in the form of isolate or concentrate, may provide value-added products for use in food and feed formulations. The flaxseed polysaccharide (mucilage) fraction, which is located on the outer seed coat, once isolated has potential use as a food gum or dietary fiber (Mazza and Oomah, 1995). 

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