OSA-maltodextrin as wall material for encapsulation of essential avocado oil by spray drying

Maltodextrin is commonly used as wall material for protection of bioactive compounds. This work explored the OSA modification of maltodextrin to improve the stability of microcapsules obtained by spray drying process. OSA maltodextrin showed a degree of substitution of 0.020 with OS groups by weight of about 2.49%. OSA maltodextrin exhibited improved emulsification capacity compared to its non-modified counterpart. The microencapsulation stability was tested with avocado essential oil, where the OSA maltodextrin presented the better conditions against adverse effects of storage conditions, as revealed by monitoring the peroxide index. OSA maltodextrin reduced by about 80% the oxidation of the essential oil as compared to its non-modified counterpart. Confocal microscopy images indicated that the improved stability of OSA microcapsules can be explained from the aggregation of particles and the reduced fraction of free oil, which avoided the exposure of the essential oil to oxidative factors.