Preparation, characterization, and prebiotic potential of resistant maltodextrin from the remaining starch in cassava...

This study aimed to produce a novel resistant maltodextrin (RMD) from the remaining starch in cassava pulp via pyrodextrinization and enzymatic hydrolysis. The optimum conditions involved a temperature of 180 °C, 0.5 % HCl, and a reaction time of 5 h, resulting in a significant RMD yield (18.6 %). In terms of its morphology, the RMD involved irregularly shaped sponge-like particles of multiple sizes, with XRD analysis indicating the loss of the original crystalline structure. The predominant relative molecular size of the product was DP 15-16 (70.9 %). Analysis of the monosaccharide composition revealed the presence of glucose (88.0 %), followed by hemicellulose-derived monosaccharides (11.1 %). Indigestible glycosidic linkages, including α-1,2, β-1,2, β-1,4, and β-1,6 linkages, were identified in the RMD using NMR spectroscopy. FTIR spectroscopy confirmed the presence of β-glycosidic linkages in the final product and revealed acetyl groups, consistent with the presence of hemicellulosic oligosaccharides, and in vitro digestibility tests revealed a highly digestion-resistant fraction of 91.7 %. Remarkably, the RMD demonstrated a potential prebiotic effect by promoting the growth of four probiotic species. These findings suggest that the starch remaining in cassava pulp is a viable source of RMD and could be utilized as a prebiotic.