Experimental study of quercetin microencapsulation using water-in-oil-in-water (W1/O/W2) double emulsion

Water-in-oil-in-water double emulsions were formulated and the release kinetics of quercetin from the internal to the external water phase was investigated as a function of oil phase (olive, red pepper seed and sunflower oils), storage temperature and time. The primary emulsion had a volume-weighted mean diameter (d([43])) between 123.45 and 195.18 nm, with an encapsulation efficiency of >90%. Although, the highest globule size was found in red pepper seed oil emulsions. The percentage of quercetin release, at the end of storage period and at 5 degrees C, ranged from 5.89 to 8.64% and the lowest amount was observed in red pepper double emulsion. Thus, the experimental data were interpreted within the frame of an Avrami's model based on release. The results revealed that double emulsion with sunflower oil possesses the highest release rate constant (k), followed by those of olive and red pepper seed oils. Thus, the release behavior was strongly influenced by the composition of the oil phase. Moreover, the results from oscillatory rheology analysis also revealed that the loss modulus predominated over the storage one in the whole frequency range. Published by Elsevier B.V.