Effect of sulfation on the physicochemical and biological properties of citrus pectins

Citrus pectins were subjected to chemical modification, specifically sulfation, and the antimicrobial and anticoagulant activities of the derivative were investigated. Compared to native pectin, the FT-IR spectra of the derivative showed two new absorption bands at 1250 cm−1 (Sdouble bond; length as m-dashO) and 810 cm−1 (C–O–S), implying that the pectin was successfully sulfated. The degree of substitution was also determined to be 0.15 by elemental analysis. In rheological measurements, sulfation gave rise to significant reduction of viscosity of pectin. Moreover, the pectin derivative exhibited improved antimicrobial effects against Bacillus cereus and Vibrio fischeri and the anticoagulant activity, which increased in a concentration-dependent manner. These results demonstrated that the incorporation of sulfate groups into the pectin structure appeared to play an important role in improving its biological activities.