Xylitol and Maltitol Improve the Rheological Property of Kappa-Carrageenan

To further extend the use of κ-carrageenan (κ-C) in real food systems (such as beverages), the understanding of gelation properties of κ-C with the presence of food ingredients is critical. The effects of xylitol and maltitol (up to 30 wt %) on the rheological and structural properties of κ-C were inspected by means of rheometer and Fourier transform infrared (FTIR). With the addition of xylitol, the gelation temperature increased from 44.1 to 57.3 °C, while the gelation temperature increased from 44.1 to 61.4 °C in maltitol systems. With the increasing concentration of both xylitol and maltitol, the values of fractal dimension d(f) and complex modulus G* of κ-C increased, while the relaxation exponent n decreased from 0.87 to 0.39 of xylitol and 0.87 to 0.78 of maltitol, respectively. These indicated that the gel networks of aqueous κ-C were improved by the addition of xylitol and maltitol. The FTIR results showed that the interaction between κ-C and these polyols contributed to the increase of hydrogen bonds. The effects of maltitol on κ-C were stronger than those of xylitol because of more equatorial-OH bonds in maltitol. These findings contribute to a better understanding of the gelation processes of κ-C/polyols systems.