Abstract:

Gelatin microspheres were prepared by an emulsification technique and characterized with microscope and
scanning electron microscope. The adsorption and desorption of various polyphenols by gelatin microspheres was
investigated, and the reusability of the microspheres was also evaluated. The results showed that when the adsorption was
carried out at 35 ℃ and pH 3.5 for 120 min, gelatin microspheres exhibited good adsorption efficiency for epigallocatechin
gallate (EGCG), punicalagins and proanthocyanidins, but demonstrated a weak adsorption for chlorogenic acid. After being
treated by distilled water at 80 ℃ for 120 min, the adsorbed polyphenols could be released effectively. When the mass
ratio of polyphenols to microspheres was 5:1, the adsorption rates of the other polyphenols except chlorogenic acid were
54%–78% with the amount of polyphenols adsorbed by per unit mass of the microspheres being 107–156 μg/mg, and the
desorption rates of the adsorbed polyphenols were 60%–75%. Moreover, the adsorption and desorption rates for EGCG
remained at over 55% after fifth repeated reuse of the microspheres, but sharply declined after eighth reuse. This study
reveals that the gelatin microspheres can be potentially applied to remove and recover polyphenols in foods.

Key words: gelatin microspheres, polyphenols, adsorption, desorption, reuse