Delivery of green tea catechins through Oil-in-Water (O/W) nanoemulsion and assessment of storage stability

Abstract The aim of the study was to produce green tea nanoemulsions using High pressure homogenization (HPH) technique to improve its physicochemical stability and release profile of green tea components for nutraceutical delivery. The solubility of EGCG in sunflower oil (SFO) was improved by 85.98 ± 2.31 mg/g of SFO with use of 1-dodecanol as carrier material. The emulsion exhibited minimum droplet diameter and highest encapsulation efficiency of 0.280 ± 0.01 μm and 83.16 ± 1.12%, respectively at homogenization pressure 60 MPa, 4 cycles and 1%, (w/v) Tween 80 concentration. When the emulsions were subjected to different environmental stress (pH, temperature and salt concentration), they were stable for 8 weeks. Among heat treatments such as low temperature longer time (LTLT) and high temperature short time (HTST), the emulsions were stable at HTST treatment in terms very less change in microstructure, droplet diameter and chemical composition. Fourier Transform Infrared Spectroscopy (FTIR) studies showed that there were no chemical interaction between carrier lipid and encapsulated catechins. Hence, when emulsion was subjected to in-vitro release in mimicked gastric condition, they showed slow and sustained release of polyphenols from lipid matrix.