Pectin gels for controlled release of a higly soluble ellagic acid salt

Introduction: The limited bioavailability of ellagic acid (EA), the main polyphenol from fermented pomegranate,1 depends on its low solubility in aqueous media (≈10µg ml-1) coupled with binding to proteins which affect its transport and absorption in the intestine.2 We report here the preparation of pectin gels as a system to vehiculate EA and to warrant its specific release under the conditions of colon compartments. Material & Methods: EA water soluble salts were obtained with L-Lysine at different molar ratios. Pectin films (high or low methoxylated) were obtained via solvent casting deposition of a pectin/EA salt/CaCl2 solution. Release was evaluated under simulated gastric or physiological pHs . Results: EA lysine salt showed a more than 400 times water solubility increase. A controlled release of EA up to about 16% over 2h was obtained from the pectin film at 10% EA and stoichiometric amount of Ca2+, while methoxylation grade was not a critical parameter. Under intestine pH conditions the release was around 27%, but negligible at gastric acidic pHs. Conclusion: A highly water soluble EA salt was dispersed in a pectin gel matrix. The release was affected by the EA salt and Ca(II), load but not by the methoxylation grade.