Preparation and evaluation of alginate-chitosan matrices loaded with red ginger oleoresin using the ionotropic gelation method

The non-volatile phenolic compounds of red ginger oleoresin are known to have high antioxidant properties to counteract a number of free radicals. Ginger oleoresin is easily degraded when exposed to air, light, water, high temperature, and low-pH conditions in the gastric area. The objective of this research was to evaluate chitosan-alginate matrices as biodegradable media for the targeted release of red ginger oleoresin in the gastrointestinal tract. The chitosan-alginate matrices were prepared using the ionotropic gelation method with varying weight ratios of chitosan to alginate. The encapsulation efficiencies, loading capacities, and cumulative release profiles were determined based on the total phenolic content of the samples. The in-vitro release assays of red ginger oleoresin in simulated gastrointestinal fluids showed that the chitosan-alginate matrices with a weight ratio of chitosan to alginate of 2:1 had a low initial cumulative release (4.3%) in simulated gastric fluid and a moderate final release in simulated colonic fluid (40.7%). The results indicated that chitosan-alginate matrices could be formulated for targeted release of red ginger oleoresin in the gastrointestinal tract and could be used as carriers to deliver bioactive compounds to the colon via oral administration.