Scanning electron microscopy of in vivo and in vitro digested starch granules of chick pea cowpea and horse gram

E. F. ki H. A.; Desikachar H. S. R.; Tareen J. A. K.; Tharanathan R. N.

The in vivo and in vitro digestibility of granular starches isolated from chick pea, cowpea and horse gram are described. Digestibility in vivo of these starches was lower than that of corn starch. Significant differences in the weights and contents of small intestine and cecum of rats, were noticeable between the control (i.e., corn starch) and the experimental groups. The cecum pH of rats fed legume starches was distinctly acidic in comparison to that of rats fed corn starch, which was neutral. Scanning electron microscopy of the residual starch granules isolated from various organs revealed characteristic degradation patterns. The in vitro digestibility using glucoamylase and salivary .alpha.-amylase revealed considerable differences among the 3 legume starches; the changes in the granule morphology brought about by the enzyme action were followed by scanning electron microscopy. Of the 3 legume starches tested chick pea starch granules appeared to be more digestible both by in vivo and in vitro systems.