Recrystallization of optimized debranched starch: Effects of concentration on resistant starch formation and...

This study explored how enzymatic hydrolysis time (1-12 h) and starch concentration (5-50 %) influence waxy wheat starch treated with pullulanase (4000 NPUN/g, pH 4.7, 58 °C) to enhance retrograded resistant starch (RS). Key findings revealed that after enzymatic hydrolysis for 8 h, the A chain (degree of polymerization DP 6-12) and B1 chain (DP13-24) significantly increased (p < 0.05), and the content of DP13-24 was the highest in wax wheat starch (52.21 % ± 0.23). This specific chain length recombination lays a structural foundation for the formation of RS. Most notably, at 50 % starch concentration, the resulting debranched waxy wheat starch exhibited 79.54 % crystallinity with A + V-type crystalline structure and achieved 59.25 % RS content, representing a 6.9-fold increase over native starch (8.85 %). These dramatic improvements were attributed to the optimized recrystallization conditions that promoted the formation of highly ordered crystalline structures while effectively inhibiting starch digestibility. These findings provide theoretical support for developing heat-resistant, low-glycemic functional foods.