Effect of Relative Humidity during Storage on the Autoxidation of Linoleic Acid Encapsulated with a Polysaccharide by Hot-Air-Drying and Freeze-Drying.

Linoleic acid was encapsulated with gum arabic, maltodextrin and pullulan at different weight ratios by hot-air-drying and freeze-drying. The autoxidation processes of the encapsulated linoleic acid were observed at 37°C and at various relative humidities. Linoleic acid encapsulated by hot-air-drying was more stable at the lower humidities regardless of the kind of wall material. Linoleic acid encapsulated with gum arabic by freeze-drying also showed a similar dependence on the humidity. Linoleic acid in the microcapsules freeze-dried with maltodextrin and pullulan was very stable against autoxidation at intermediate humidities, while it was very easily autoxidized at low or high humidity. This tendency was remarkable for microcapsules prepared with pullulan.