Resumen de Preparation and Oxidation Stability Evaluation of Tea Polyphenols‐Loaded Inverse Micro‐Emulsion
Xiaohong Lan, Jingjing Sun, Ying Yang, Mengjie Chen, Jianhua Liu, Jihong Wu, Zhengfu Wang
Compared to synthetic antioxidants, tea polyphenols (TPs) has its own advantages in edible oil industry, however, the hydrophilic properties have restricted its applications. In this study, the ternary phase diagram of TPs‐loaded micro‐emulsion (ME) system was constructed, in which glyceryl monooleate (GMO), Tween80, linoleic acid as the surfactants, ethanol as the co‐surfactant and soybean, corn, sunflower oil as the oil phase, have been used for the preparation of ME. The results indicated that a composition of ME (57.5% oil, 18% Tween80, 18% GMO, 4% Linolic acid, and 2.5% water+ethanol) could dissolve maximum water and could stable for 2 mo at room temperature with an average diameter of 6 to 7 nm, as detected by means of dynamic light scattering (DLS). The loaded of TPs into ME led to an increase of particle size to 15 to 16 nm, due to increased polarity of the water phase. The antioxidant capacity of TPs in ME was characterized by the peroxide value (POV) method. The addition of 1% water phase with 0.1 g/mL TPs could retain the POV at low value for 30 d at accelerating temperature 50 °C. Meanwhile, comparing the three edible oil, ME with corn oil has lower conductivity and higher value of POV during the storage. This work provides an efficient and environmentally friendly approach for the preparation of TPs‐loaded ME, which is beneficial to the application of TPs in edible oil. The use of inverse micro‐emulsion (ME) to increase solubility of TPs in edible oils may provide an efficient and environmentally friendly approach for the preparation of TPs‐loaded MEs, and the slow release effect can further enhance the antioxidant effects. This method will broaden the application of TPs in the field of edible oil, and meet the requirement of health and safety standards.
