The purposes of this research were to develop water-in-oil-in-water double emulsion (DE) for co-loading EGCG and piperine as its marker compounds, and to determine its physicochemical properties. Stable DE was produced based on our previous research. Briefly, for oil phase (O), olive oil, glycerol ester of wood rosin, polyglycerol polyricinoleate, piperine, and for interior water phase (W1), deionized water, gelatin, sodium chloride, ascorbic acid, and EGCG were mixed and heated up to 60°C. Thereafter, W1 was dispersed into O dropwisely followed by magnetic stirring, high-shear homogenization, and ultrasonication, respectively. Produced water-in-oil primary emulsion (PE) was rested at 4°C for 30 min. For exterior water phase (W2), deionized water, sodium chloride, ascorbic acid, and polyoxyethylene sorbitan monooleate were mixed. Thereafter, PE was dispersed into W2 dropwisely followed by magnetic stirring, ultrasonication, and high pressure homogenization, respectively. The structure of DE was observed through optical and transmission electron microscopy. And the influence of applying time of high pressure homogenization on the stability of DE was determined. Also, in vitro release characteristics of DE was investigated by using HPLC. Optimized stable DE would be an attractive delivery system for co-loading both hydrophilic and lipophilic bioactive compounds simultaneously. And, once developed, it can be applied to the various food applications such as beverage in a wide range of formulations.

Piperine, component of pure ground black pepper, has strong stimulative and trot. Analytical method for piperine was developed by high performance liquid chromatography. Analytical conditions are as follows; mobile phase is 70% methanol, detector LTV 343 nm (0.05 AuFa), column is Novapak 5 C_(10) (15 cm × 4.6 mm), flow rate is 1.0 ml/min, chart speed is 0.25 cm/ min and intjection volume is 20 Etl. Analytical results are as follows that relative standard deviation is 1.15%, calibration curve is y=170473.1×-7848.5 (R²=0.999) that shows good linearity. Standard solution of piperine is stable up to 10 hr and content of piperine in pure ground black pepper is 4.97±0.86%. Retention time of piperine in HPLC method is about 7 min. Therefore, the developed HPLC method including simple pretreatment of sample will be contribute to quality management.