Properties of caraway (Carum carvi L.) essential oil encapsulated into milk protein-based matrices

Encapsulating properties of whey protein concentrate (WPC), skimmed milk po wder (SMP), and their mixtures with maltodextrins (MD) for encapsulation of caraway essential oil by spray drying were studied. Encapsulation efficien cy (EE) was higher in WPC-based matrices compared to SMP. Partial replaceme nt of WPC by various MD increased the retention of volatiles during spray d rying and enhanced protective properties of solidified capsules against oxi dation and release of volatiles during storage. The opposite tendency was s hown by SMP matrices: adding MD to the wall composition resulted in lower r etention of volatiles during drying and lower oxidation stability compared to the SMP and all WPC based matrices. Dynamic headspace analysis (DHS) was applied to determine the rate of release of volatiles from the microencaps ulated powders. Results revealed that combined matrices of SMP and carbohyd rates had the highest volatile release ratio. Partial replacement of WPC by MD significantly reduced release of volatiles from capsules as determined by DHS. Flavor profile of caraway oil entrapped in the matrix was similar t o that of pure essential oil: a small decrease in limonene content was reco rded for some matrices. The results of scanning electron microscopy (SEM) o f microencapsulated particles showed WPC-based matrices to have less visibl e cracks and holes compared to SMP. More dented surfaces could be observed in particles containing MD as compared to WPC only. It was concluded that W PC-based matrices were more effective as caraway oil encapsulating agents a s compared to those of SMP. The incorporation of carbohydrates to WPC resul ts in obtaining more effective microencapsulants.