The positive effects of phenolic compounds in the gastrointestinal tract are influenced by dietary fibers. The aim of this work was to study the interactions between syringic acid and soluble and insoluble dietary fibers from the β-glucan group, including laminarin from Laminaria digitata, zymosan A from Saccharomyces cerevisiae and β-glucan from Euglena gracilis. Kinetic models of the pseudo-first and pseudo-second order were applied to describe the interactions in time. The stability of the complexes between syringic acid and dietary fibers was monitored at different times by the DPPH method. The water holding capacity, water swelling capacity and water solubility of dietary fibers were determined. FTIR spectra were recorded to characterize the possible binding of syringic acid and dietary fibers. The results showed that syringic acid adsorbed onto dietary fibers with different adsorption capacities. The highest adsorption capacity was observed for zymosan A (431 mg g−1), followed by laminarin (382 mg g−1) and β-glucan from Euglena gracilis (336 mg g−1). The parameters of the kinetic models showed good agreement with the experimental data. The highest antiradical activity was found for the complex of syringic acid—β-glucan from Euglena gracilis. The FTIR spectrum confirmed the bonding of syringic acid onto dietary fibers. The interactions of polyphenols and dietary fibers are important to understand the role of dietary fibers as carriers of polyphenols.
Matić et al. (Sun,) studied this question.