The utilisation and fermentation of highly cross-linked phosphate starches made from two different origins, potato (HXL-P) and tapioca (HXL-T) were investigated in rats and humans. HXL-P and HXL-T were highly resistant to digestion by carbohydrate enzymes and were also resistant to fermentation by gut microbiota in rats. The postprandial blood glucose scarcely increased after administration of HXL-P or HXL-T in healthy humans. Incremental AUC of both HXL-P and HXL-T for 180 min was significantly lower than that of glucose (p < .05). Breath hydrogen excretion was very low after oral administration of HXL-P or HXL-T, and AUCs of breath hydrogen excretion for 13 h after administration were significantly lower than that of fructooligosaccharide as a reference of fermentation (p < .05). These results show that HXL-P and HXL-T were hardly digested and were highly resistant to fermentation. In conclusion, HXL-P and HXL-T could be good low-energy bulking ingredients to replace wheat flour.
Keywords: Fermentation; highly cross-linked phosphate starch; potato; resistant starch; tapioca; utilisation.