Formation of essential oil containing microparticles comprising a hydrogenated vegetable oil matrix and characterisation thereof

Abstract

Microparticles with different essential oil concentrations 0, 75, 150, 225 and 300 gkg⁻¹, (g of essential oil per kg of microparticles), were produced by dispersing the essential oils within a hydrogenated vegetable fat matrix and forming spherical solid particles by spray-chilling. Size distribution, flowability, surface structure, essential oil recovery, melting properties and crystallinity of the microparticles were determined. With over 225 gkg⁻¹ essential oil the microparticle surface became stickier, their flowability was reduced and the size distribution broadened. Gas chromatography showed that the essential oil recovery was always above 85% v/v. The surface structure of the microparticles was strongly affected by the essential oil concentration being smooth (225 gkg⁻¹), comprising round-shaped dumps (300 gkg⁻¹) or showing fat blooming (0, 75, 150 gkg⁻¹). With essential oil, the formation of the β-polymorphic form of the triglycerides was supported leading to changes in the melting behaviour and the crystalline structure.

Keywords:

• Essential oils
• microencapsulation
• spray-chilling
• hydrogenated vegetable fat
• melting behaviour
• crystallinity

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was supported by the BIOMIN Holding GmbH. The authors want to thank BIOMIN for their financial and scientific support.