Development of a novel resistant starch via synergistic triple modification strategy that enables lipid complexation...

To address the limitations of conventional resistant starches (RSs) cannot simultaneously inhibit the absorption of starch and lipids, a novel RS was synthesized via a synergistic enzymatic (combined branching and amylolysis) -physical-chemical triple modification strategy. After enzymatic modification to optimize the amylose content and average degree of polymerization, physical modification to create empty V-type helical cavities, and esterification to increase resistance, the final modified starch (E-P-C) exhibited both a high RS content of 69.7. X-ray diffraction and laser confocal microscopy-Raman analyses revealed that the short-range crystalline order of the E-P-C starch was improved despite disrupted long-range order crystallinity. It's confirmed that the E-P-C starch had the capacity for lipid complexation under mild conditions with complexing index (CI) of 43.4 %, followed the order of medium chain > long chain > short chain fatty acids. In vitro digestion experiments demonstrated that the E-P-C starch sequestered 19 % of the fatty acids in three phase noncomplexation → weak complexation → strong complexation, while retaining 67.23 % of the RS content in the digestive juice, indicating the potential prebiotic functionality. This work provides a scalable strategy to engineer starches that can modulate starch digestibility and lipid bioavailability concurrently to address key challenges in obesity management.