Microencapsulation of soybean oil by spray drying using oleosomes

The food industry has discovered that oleosomes are beneficial as carriers of bioactive ingredients. Oleosomes are subcellular oil droplets typically found in plant seeds. Within seeds, they exist as pre-emulsified oil high in unsaturated fatty acids, stabilised by a monolayer of phospholipids and proteins, called oleosins. Oleosins are anchored into the oil core with a hydrophobic domain, while the hydrophilic domains remain on the oleosome surface. To preserve the nutritional value of the oil and the function of oleosomes, microencapsulation by means of spray drying is a promising technique. For the microencapsulation of oleosomes, maltodextrin was used. To achieve a high oil encapsulation efficiency, optimal process parameters needed to be established. In order to better understand the mechanisms of drying behind powder formation and the associated powder properties, the findings obtained using different microscopic and spectroscopic measurements were correlated with each other. By doing this, it was found that spray drying of pure oleosome emulsions resulted in excessive component segregation and thus in a poor encapsulation efficiency. With the addition of maltodextrin, the oil encapsulation efficiency was significantly improved.