Production, Properties and Swelling of Copper-Pectic Gel Particles in an Artificial Gastroenteric Environment

The purpose of the this research was to obtain and study the properties of copper-pectic gel particles (CuPGPs) obtained from aqueous solutions of apple pectin (AP) in the concentration range of 1%-5% in the presence of Cu2+ ions. Methods and Results: We used commercial AP AU701 (Herbstreith & Fox KG, Germany). CuPGPs were obtained from aqueous solutions of AP (1%, 3%, 5%) in the presence of Cu2+ ions (1%-10%) by the method of ionotropic gelation. The diameter and density of the CuPGPs were determined. Dry CuPGPs formed from 5% AP with all tested concentrations of copper ions have the largest diameter (0.96-1.15 mm), and gel particles formed on the basis of 1% AP have the smallest diameter (0.42-0.74 mm). CuPGPs formed from 5% AP have the highest density (1.43-1.65 mg/mm(3)), and CuPGPs formed on the basis of 1% AP have the lowest density (0.65-0.92 mg/mm(3)). Gel particles obtained from 1% AP swelled in simulated gastric fluid (SGF) by 161% and then completely degraded immediately upon entering in simulated intestinal fluid (SIF). CuPGPs obtained from 3% AP swelled by 166% in SGF and 148% in SIF, and completely degraded in SIF after 2.5 hours of incubation in it. Gel particles obtained from 5% AP in the presence of 10% Cu2+ swelled most strongly - by 173% in SGF and by 208% in SIF. And then, they degraded after 8 hours of incubation in simulated colonic fluid (SCF).