ANTI-NUTRITIONAL CONSTITUENT OF COLOCASIA ESCULENTA ...

B.S.l a-Amylase inhibitor
B.S.2 Saponin
CHAPTERB-5
GENERAL CONCLUSION
Two active forms of the inhibitor, AI-AI and AI-B2, were detected during the
purification procedures. The apparent molecular weights, based on gel chromatography
on Sephadex G-lOO, were approximately 17 kDa and 19 kDa respectively.
The optimum pH and temperature for the a-amylase inlubitors were pH 6 and 40· C
respectively, but the enzyme activity was significantly destroyed at pH less than four and
more than eight, as well as above a temperature of70· C.
The results obtained for the studied a-amylase inhibitors present in Amadumbe are in
agreement with the inlubitors studied for other tubers. The Amadumbe amylase inhibitors
may not be of much nutritional relevance, since cooking was found to decrease their
biological activity.
The isolated compound characterized by TLC, IR and GC-MS was found to be gamma­
sitosterol.
The objective ofthe next section was to conduct a nutritional evaluation using one ofthe
isolated anti-nutritional factors. Beta-sitosterol has many biological activities and is an
isomer of gamma-sitosterol. Therefore, it was decided to conduct the nutritional
evaluation using gamma-sitosterol. Gamma-sitosterol was not commercially available,
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