Encapsulation of flavonoid in multiple emulsion using spinning disc reactor technology

Rutin (quercetin-3-rutinoside) and anthocyanin flavonoids have numerous biological activities which are beneficial to human health such as antioxidant and anti-inflammatory effects. In order to aid delivery of their health benefits, an attempt has been made to encapsulate rutin and Hibiscus anthocyanins in multiple emulsions using a spinning disc reactor (SDR) as a novel processing aid. The encapsulation of flavonoids may prolong their shelf-life and increase their bioavailability for absorption by the body (Munin & Edwards-Levy, 2011). The advantage of using SDR technology in the second stage of emulsification is that it does not break the droplets of the primary emulsion. The time-dependent stability of the multiple emulsions was investigated using particle size, microscopy, visual assessment and stability index measurements. At 2 wt.% emulsifier, Brij 78 was found to be capable of producing uniform droplets of the final W/O/W emulsion in the size range of 13-15 mu m. The results show that the SDR technology can be used as an alternative process for making stable W/O/W multiple emulsions with a fairly narrow droplet size distribution. Rutin and anthocyanins were successfully encapsulated within the internal aqueous phase of W/O/W multiple emulsions, giving an encapsulation efficiency of >80%. In the presence of flavonoids, a reduction in the average particle size has also been observed, possibly due to its surface active properties. Confocal laser microscopy confirmed the successful formation of SDR-processed multiple emulsions. (c) 2012 Elsevier Ltd. All rights reserved.