In vitro fermentabilities of raw and cooked canna starches and their derivatives

The undigested residues remaining after amylase hydrolysis of raw and cooked canna starches, including native, retrograded, retrograded debranched, heat-moisture treated (HMT), hydroxypropylated and cross-linked starches, were in vitro fermented with pig cecal content. Fermentation of raw native canna starch generated butyric acid as a main short-chain fatty acid (SCFA), while acetic acid was a major component of SCFAs derived from raw modified starches. For cooked starches, the highest butyric acid concentration was found in cross-linked starch (28.8 mM), followed by retrograded debranched starch (26.0 mM). On the basis of initial weight of starches, retrograded debranched starch was the best substrate since it produced the highest amounts of SCFAs (295.7 mmol/100 g starch) and butyric acid (86.8 mmol/100 g starch) after 3 d of fermentation.