Effect of oil content and drying method on bulk properties and stability of powdered emulsions with OSA starch and linseed oil

- The spray or freeze drying of emulsions with OSA starch and trehalose were used to encapsulate linseed oil.
- More effective microencapsulation of oil was achieved by spray-drying.
- The oil content had no significant effect on the flowability of powders.
- The drying process caused no significant changes in the stability of reconstituted emulsions.
- High-oil powders with OSA starch indicate potential applicability as creamers.

The spray drying and freeze-drying of oil-in-water emulsions stabilized with tapioca OSA starch and trehalose (1:2), enabled producing high-fat powders (containing 40 and 55% of linseed oil). More effective microencapsulation of oil in powders with oil content above 50% was achieved by spray drying. The modification of oil content had no significant effect on the flowability of powders. Reconstitution properties of powders in water were significantly affected by the drying method. Turbidimetric measurement proved that the drying process did not cause any significant changes in the structure and physical stability of reconstituted emulsions. The application of powders as a savory creamer showed the lack of any substantial quality changes of color caused by water hardness. The peroxide value (PV) of microencapsulated linseed oil extracted from powders stored in barrier packages was higher than the PV of a control sample of bulk oil. Adverse changes of the UFA/SFA ratio, indicating the proportion between unsaturated and saturated fatty acids, were observed in oil extracted from stored powders.