Autoxidation of Linoleic Acid Encapsulated with Polysaccharides of Differing Weight Ratio

Linoleic acid was encapsulated with pullulan, maltodextrin and gum arabic at various weight ratios of the fatty acid to wall material by the hot-air-drying method. The autoxidative process of the encapsulated linoleic acids was observed at 37°C and at a relative humidity of 75%. The weight ratio strongly affected the autoxidative process, autoxidation being more suppressed with smaller ratios. The autoxidation process of encapsulated linoleic acid leveled off at fraction Y∞ of the unoxidized substrate within 15 days. The Y∞ value strongly depended on both the ratio and the wall material, and steeply decreased near the ratio of 0.75 for every wall material. The dependence of the Y∞ value on the weight ratio was analyzed by the two- and three-dimensional models for percolation theory. The two-dimensional model expressed well the experimentally observed dependence.