Synthesis of Pyrodextrins and Enzymatically Resistant Maltodextrins from Makal (Xanthosoma yucatenensis) Starch

Research background. Enzymatically resistant maltodextrins (ERM) are a resistant starch (RS) type 4, synthesized from native starch. They are obtained through sequential application of two processes: pyrodextrinization (PDX), which produces pyrodextrins, and complementary hydrolysis (CH), which generates ERM. These processes produce atypical bonds and confer characteristics similar to dietary fiber to pyrodextrins and ERM, such as resistance to digestion. The objective of this work was to obtain and evaluate some physicochemical characteristics of pyrodextrins and ERM produced from native starch isolated from makal (Xanthosoma yucatanense) tubers. Experimental approach. PDX and CH were performed by applying factorial designs. For PDX, factors and their levels were starch concentration/2.2 M HCl ratio (80/1 and 160/1 m/V), temperature (90 and 110 °C), and reaction time (1 and 3 h); while for CH were α-amylase-pyrodextrin concentration (0.5 and 1 µL/mL) and reaction time (10 and 30 min). The physicochemical profile included determination of RS content, estimation of color change (ΔE), microscopy, and determination of dextrose equivalents (DE). Results and conclusions. The best factorial treatment for PDX was at the 160:1 m/V, 90 °C and 3 h levels since it presented the highest RS content (84.73 %) and a lowest ΔE (3.742). Due to its low DE (13.89 %), increased RS (90.73 %), and low ΔE (4.24), ERM resulting from CH with the 0.5 µL/mL α-amylase pyrodextrin concentration and 10 min levels was selected as the best treatment. Novelty and scientific contribution. Results show that pyrodextrins and ERM obtained from makal can be used as ingredients for functional foods development, due to their high proportion of non-digestible material and low browning degree.