Formation and stability study of flavor oil emulsions stabilized by polyglycerol esters and by sucrose esters

Abstract

In this work, flavor oil emulsions contained 5 wt% oil and 0.75 wt% emulsifier were formulated by using different combinations between flavor oils and food emulsifiers. Orange oil (00), peppermint oil (PO), polyglycerol monostearate (PGE), and sucrose monostearate (SE) were employed to form emulsions by ultrasonic homogenization. Heat stability (storage at 100°C for 30 min) and freeze-thaw stability (storage at -20°C for 22 h. and at 30°C for 2 h.) of emulsions were investigated by observing droplets under a microscope, determining mean droplet sizes, and measuring amounts of destabilized oil. Ostwald ripening stability of emulsions was determined by measuring the droplet size distribution changes over 48 days of storage. The results showed that flavor oil emulsions stabilized by PGE and by SE were heat stable. Interestingly, flavo.r oil emulsions stabilized by PGE had better freeze- thaw stability compared to emulsions stabilized by SE. This property of PGE was suggested from polyglycerol interfacial layers reduced ice crystallization and reduced coalescence. The flavor oil emulsions stabilized by either PGE or SE underwent through Ostwald ripening destabilization and the ripening stability was improved by using mixed emulsifiers between PGE and SE. The information from this study could be useful for creating formulations of flavor oil emulsions that suitable for future applications in foods and beverages.