Preparation, characterization, and in vitro antioxidant activity of pH-sensitive resveratrol microcapsule in simulated intestinal fluids

Shellac resin ammonium salts (SRAS) were prepared from the natural product of shellac resin and ammonium hydroxide by amidation. Resveratrol (RES) was embedded with SRAS to improve its thermostability, antioxidant activity, and bioavailability. The absorption of RES was promoted in the intestinal tract. Meanwhile, an enteric-coated microcapsule-loaded RES was successfully established by spray drying technology. The RES microcapsule exhibited a spherical shape and perfect stability as well as outstanding sustainable release character in simulated intestinal release experiment. Moreover, SRAS/RES presented a dose-dependent manner with a much higher radical scavenging activity of DPPH center dot and ABTS(+) compared to the pure RES. Therefore, a kind of new pH-sensitive RES microcapsule established may act as a favorable carrier for an insoluble antioxidant ingredient in the potentially new food delivery system on functional food supplements.