Pickering emulsions based on CaCl₂-gelatinized oat starch

The aim of this study was to investigate calcium chloride-induced gelatinization of oat starch, and its effects on the properties of oat starch-based Pickering emulsions. The starch granules were gelatinized in CaCl₂ for up to 24 h and the results indicate that the salt-induced gelatinization of oat granules is not a surface phenomenon, as gelatinization and dissolution of the whole starch granule was observed. The degree of swelling differed with time and for emulsions the creaming layer changed depending on the length of salt-induced gelatinization; the least dense layer being observed after 30 min of gelatinization. The study also included OSA-modified starch. OSA modification of oat starch led to a slight decrease in the droplet size in the resulting emulsion, but the macroscopic properties of the emulsions made with OSA-modified and non-OSA-modified oat starch granules were similar. It was also investigated whether emulsions made from non-gelatinized oat starch could be gelatinized in situ. This was found to be possible and led to encapsulation of the oil. The gelatinized emulsions could be dialyzed and lyophilized without loss of oil. Leading to dry emulsions that was reformed upon reconstitution with water.