Preparation and characterization of cross-linked short-chain glucan aggregates (CL-SCGA)

Abstract

In this study, short-chain glucan aggregates (SCGA) were cross-linked using sodium trimetaphosphate (STMP) and sodium tripolyphosphate (STPP) at varying degrees (0-12 %). With increasing cross-linking reagent, phosphorus content and degree of substitution (DS) increased, reaching 0.3209 % and 0.017. All samples exhibited spherical morphology with particle sizes ranging from 0.9 to 1.1 μm. The zeta potential became more negative (-18.3 to -26.5 mV), indicating improved colloidal stability. Among them, 4CL-SCGA maintained dispersion stability for up to 6 h. Thermal analysis showed broader melting temperature ranges (Tc-To) and higher enthalpy (ΔH, up to 37.3 J/g) with increasing DS, suggesting improved thermal stability. CL-SCGAs showed the highest resistant starch (RS) content after in vitro digestion (up to 54.26 %), and retained significantly high levels even after gelatinization. These results demonstrate that cross-linking effectively improves the physicochemical and digestive properties of SCGA, enhancing its potential use in functional food applications.

Keywords: Cross-linking; Physicochemical properties; Pullulanase; Short-chain glucan aggregates.