ANTI-NUTRITIONAL CONSTITUENT OF COLOCASIA ESCULENTA ...

Digestive enzymes do the all important work of hydrolyzing food into the nutritional
components required to build and maintain health.
Disaccharides (sucrose, lactose and maltose) are important sources of metabolic energy
(Dilworth et al. 2005). Disaccharidases are integral enzymes ofthe small intestinal brush
border membrane responsible for the hydrolysis of carbohydrates which must occur
before monosaccharides can be absorbed (Lorenzsonn et al., 1987; Re et aI., 2006).
These enzymes are sucrase (BC 3.2.1.26), lactase (BC 3.2.1.23) and maltase (BC
3.2.1.20) respectively. The end-products (glucose and fructose, galactose) resulting from
the activities ofthese enzymes are actively translocated from the intestine to the blood by
ATPases (Dilworth et al., 2005).
Although the factors controlling the development of intestinal disaccharidases are not
known (HeIZenberg and Rerzenberg, 1959), it appears that the intestinal dissacharidases
of mammals develop in a way that allows the utilization of the carbohydrates that the
animal is likely to encounter under natural feeding conditions (Siddons, 1969). Thns,
dissacharidase activities appear to be broadly correlated to dietary habits (Vonk and
Western, 1985). Food influences the brush border enzyme activity in rats and is also
necessary for the maintenance ofnormal mucosal stability (Yamada et al., 1981; Rolt and
Yeh, 1992). Thus, the activities ofspecific enzymes are reduced when their substrates are
sporadic or absent from an animal's diets (Zarling and Mobarhan, 1987; Rivera-Sagredo
et aI., 1992).
On the other hand, studies suggest that carbohydrate intake increase dissacharidase
activities (Shinohara et al., 1986; Samulitis-Dos et aI., 1992). The overall digestive
capacity ofan animal is sensitive to changes in the concentrations of intestinal enzymes.
These changes may affect the nutritional status of the animal, as well as the functioning
of other systems, including neurological, renal, cardiac and pulmonary systems (Lee et
al.,2003).
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