Abstract
Clustered amylopectins (CAPs) were produced using recombinant glycogen branching enzymes from Escherichia coli K12 (EcGBE) and Vibrio vulnificus (VvGBE). The CAPs were esterified with octenyl succinic anhydride (OSA), introducing novel functional characteristics. Vv-CAP demonstrated a reduced apparent molecular weight and a higher prevalence of both short (degree of polymerization (DP) ≤ 5, 13.3%) and medium branches (5 < DP ≤ 12, 58.2%) compared to Ec-CAP. FT-IR spectra confirmed the successful esterification of CAPs with OSA. (1)H-NMR analysis showed the degree of substitution (DS) for OSA-CAPs varied based on the CAP to OSA ratio (DS 0.021-0.058 for Ec-CAP and 0.011-0.066 for Vv-CAP). Esterification with OSA on shortened branches resulted in a slower digestion rate and increased resistant starch proportion. Additionally, this process enhanced the emulsifying properties of CAPs and improved the aqueous solubility of puerarin. OSA-modified CAPs are promising for pharmaceutical applications. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10068-025-01892-1.