Dual cross-linking with tannic acid and transglutaminase improves microcapsule stability and encapsulates lemon essential oil for food preservation

The microencapsulation of essential oils by complex coacervation technology has attracted considerable attention. This paper deals with the preparation of gelatin-chitosan microcapsules through dual cross-linking using transglutaminase (TGase) and tannic acid (TA). Lemon essential oil (LEO) was successfully encapsulated with 82.5 % encapsulation efficiency. Compared to single cross-linking microcapsules (TG), dual cross-linking microcapsules (TG-TA) exhibit superior thermal stability and swell stability. In vitro release studies demonstrated that TG-TA exhibited better controlled-release behavior with a longer duration of action. Meanwhile, the lipid oxidation of TG-TA was 1.45 mg MDA/kg that of control group was 2.23 mg MDA/kg which showed their excellent antioxidant effects. Moreover TG-TA have higher antibacterial rate, more inhibition zone diameters and better effect for preventing the growth of total viable count than TG and LEO. This study has theoretical implications for the use of TG-TA ideal carriers for protecting various active substances, thus facilitating their applications in food preservation.