Biofabrication, structure, and functional characteristics of a reuteran-like glucan with low digestibility

A novel reuteran-like glucan with low digestibility was fabricated using microbial glucanotransferase (GTase) treated maltodextrin. For GTase treated maltodextrin with DE 6, the molecular weight of reuteran-like glucan increased from 8.35 × 10⁴ to 5.14 × 10⁶ g/mol in the initial 6 h, increasing to 1.47 × 10⁷ g/mol at 72 h. The short chain fraction (DP 3-12) of reuteran-like glucan increased from 45.2 % to 100.0 %, accompanied by an increase in α-1,6 glycosidic linkage percentage from 3.9 % to 33.3 %. This reaction promoted rearrangements in glycosidic chains, leading to a substantial increase in resistant starch content (13.4 % to 37.4 %) in the reuteran-like glucan. During in vitro fecal fermentation for 48 h, the reuteran-like glucan yielded large amounts of short-chain fatty acids (212.33 mM), especially butyric acid (12.64 mM). Thus, reuteran-like glucan could be used as a low-digestible and highly fermentable fiber for controlling blood glucose levels and prebiotic potential.