The Effect of in Vitro Digestion on the Structural, Morphologic Characteristics and Fermentability of Raw Banana Starch

Abstract

This study aimed to observe the effect of in vitro digestion on the structural and morphologic characteristics, and find the relationship between in vitro digestion and colonic fermentation of raw banana starch. After digested by artificial gastric juice and artificial intestinal juice, the starch granules were damaged, but not drastic. X-ray diffractograms showed that the crystal polymorph (C-type) was not changed and the degree of crystallinity was increased after digestion. There were no significant differences in chemical structure according to the infrared spectrum analysis. The swelling power and solubility of the digested starches were greater than that of raw banana starch at all temperatures. Banana starches digested by gastric and intestinal juice presented high fermentability, expressed by total short chain fatty acids. The results may be due to the slight changes on structural and morphologic characteristics. To conclude, passage through the stomach and small intestine increased susceptibility of raw banana starch to further fermentation, to increase the production of metabolically active short chain fatty acids.