Encapsulation of Polyphenols in Double Water-in-Oil-in-Water Emulsions Stabilized by Polyglycerol Polyricinoleate and Tunisian Arabic Gum

Water-in-oil-in-water (W1/O/W2) double emulsions have been formulated using polyglycerol polyricinoleate (PGPR) to stabilize the reverse W1/O emulsions and Arabic Gum extracted from Bouhedma National Park in Sidi Bouzid in Tunisia to stabilize the direct emulsion, in order to encapsulate two polyphenols, oleuropein and green tea leaves polyphenol. These two polyphenols exhibit an antiradical activity. The Tunisian Arabic Gum allows obtaining a narrow size distribution for the double emulsions. Due to the presence of Arabic gum in W2, the deduction of the encapsulation efficiency, from UV-vis spectrometry measurements, is not straightforward, but the final obtained values are very high (>95%), making these double emulsions with a minimal list of ingredients interesting systems. Then, the kinetic stability of these capsule-type systems has been assessed at three storage temperatures. While the double emulsions are kinetically stable at 4 °C and at room temperature, destabilization occurs at 50 °C, the mechanism of which is discussed.