Development of a Novel Resistant Maltodextrin from Cassava Pulp as a Carbon Source for Selected Probiotic Bacteria

This study aimed to develop a novel resistant maltodextrin (RMD), a water-soluble dietary fiber, from the residual starch in cassava pulp. The preparation process involved converting the residual starch to RMD through pyrodextrinization, in which dried starch was subjected to high-temperature treatment under acidic conditions for a specific duration, followed by enzymatic hydrolysis. The optimal conditions—180 °C, 0.5 % HCl, and a reaction time of 5 h—yielded 18.6 % RMD (70.9% DP 15–16). The obtained RMD was evaluated as a carbon source for representative probiotic strains including Limosilactobacillus reuteri, Lactiplantibacillus plantarum, Lactobacillus jensenii, and Lactobacillus casei. The results demonstrated enhanced bacterial growth and a greater reduction in pH. All probiotics showed rapid growth within 24 h, with L. reuteri, L. plantarum, L. jensenii, and L. casei reaching 7.8, 8.3, 8.4, and 8.6 log CFU/mL, respectively, comparable to glucose. The prebiotic indices for L. reuteri, L. plantarum, L. jensenii, and L. casei were 0.94, 0.95, 0.92, and 0.95, respectively, when using RMD as the carbon source. However, after 72 h, L. reuteri, L. plantarum, and L. jensenii exhibited a notable decline in viability when cultivated in glucose, whereas their survival was better sustained in the obtained RMD. These findings suggest that the remaining starch in cassava pulp is a viable source for RMD production and may serve as a potential carbon source for probiotic growth, contributing to the development of prebiotic functional foods.