Preparation, Characterization and Prebiotic Evaluation of Resistant Starch from Cassava Starch via Heat- Moisture Treatment and Sequential Enzymatic Hydrolysis

This study aimed to produce a novel resistant starch product (RSP) from cassava starch using heat-moisture treatment (HMT) and enzymatic hydrolysis. The effects of HMT were investigated at moisture levels of 15, 20, 25, and 30 %, with heating by autoclave at 121 °C for 1 h, followed by enzymatic hydrolysis. The RSP obtained from HMT at 25 % moisture and subsequent enzymatic hydrolysis (RSP-HMT-25) achieved a significant yield of 23.2 %. In terms of morphological analysis revealed that RSP-HMT-25 lost its original granule structure and formed aggregated particles. The X-ray diffraction pattern of RSP-HMT-25 confirm the presence of A-type starch with 20.9 % crystallinity. The prebiotic potential of RSP-HMT-25 was evaluated in vitro using Limosilactobacillus reuteri and Lacticaseibacillus casei as representative probiotics. The results demonstrated enhanced bacterial growth, as the production of essential enzymes facilitated the breakdown of RSP-HMT-25, enabling its utilization as an energy source. Furthermore, the pH was greatly reduced through production of SCFAs, including acetic, propionic, and butyric acids. These findings highlight the significant alteration in cassava starch properties through HMT and enzymatic hydrolysis, improving its prebiotic activity. Cassava starch modified via HMT has potential applications in prebiotic supplements and functional foods, offering an alternative ingredient to promote gut health.