Nano-encapsulation of saffron extract through double-layered multiple emulsions of pectin and whey protein concentrate

In this study, nano-particles of saffron extract (<100 nm) were encapsulated by spray drying. For this objective, the primary saffron water extract-in-oil (W/O) micro-emulsion containing 10% (w/w) saffron extract was re-emulsified in order to prepare W/O/W multiple emulsions, with a dispersed mass fraction of 0.25, and stabilized using protein (whey protein concentrate (WPC))/polysaccharide (pectin). Also, the encapsulation efficiency of crocin, picrocrocin and saffranal as core materials and surface characteristics of spray dried powders were investigated. Our results revealed that W/O/W multiple emulsions stabilized by sequential adsorption of WPC/pectin was the most efficient technique resulting in the better encapsulated efficiency for crocin, picrocrocin and saffranal, low yellow color (b∗) surface and, smooth surface in final powders, mainly due to fabrication of stable wall materials obtained by sequential adsorption of WPC and pectin.