Stability and antioxidant activity of chitosan/β-Lactoglobulin on anthocyanins from Aronia melanocarpa

The anthocyanins from Aronia melanocarpa (AAM) have captured the interest of researchers because of their potential health-related functionalities. However, the application of anthocyanins is limited by their poor stability. Therefore, to improve their physical and oxidative stability, single factor and orthogonal tests were designed to optimize the preparation conditions of chitosan/β-Lactoglobulin encapsulating AAM (M-AAM) and evaluated the nanocapsules in terms of their physicochemical characteristics, storage stability, and the oxidant stability during in vitro simulated digestion. Results showed that the optimal synthesis conditions for M-AAM were determined to be as follows: pH of 6, chitosan/β-lactoglobulin ratio of 1:5 (g/g), core-to-wall ratio of 1:5 (g/g), wall material concentration of 1.25%, and stirring time for 1.0 h. Under these conditions, the embedding rate of AAM reached 77.36%. AAM and M-AAM were suitable for storage at 4 °C and in darkness, chitosan/β-Lactoglobulin nanoparticles significantly improved anthocyanin retention rate in different storage conditions. Moreover, encapsulation protected AAM from gastric digestion and prolonged the retention time of AAM in the intestinal tract. Furthermore, the antioxidant effect of M-AAM improved significantly after in vitro simulated digestion. Therefore, the stability and antioxidant properties of AAM were improved via encapsulation within chitosan/β-Lactoglobulin nanocapsules.