Anthony Wragg

Novel Microencapsulation System to Improve Controlled Delivery of Cup Aroma During Preparation of Hot Instant Coffee Beverages

Aromatized water-immiscible volatile carrier liquids were emulsified into aerated aqueous coffee solution and frozen droplets desiccated in soluble coffee powder at room temperature to create small capsules that float while dissolving in hot water. The capsules provided stronger aroma than encapsulated aromatized oils and prevented oil slicks. Carriers with relatively low boiling point and water solubility hastened capsule dissolution and aroma release. Carrier-free systems were created by discarding the most water-soluble and least-volatile components from condensed coffee aromas before droplets were encapsulated. When oil-free capsules were added to instant coffee and combined with hot water, they dissolved on the beverage surface and released floating droplets that evaporated to provide intense aroma without adverse effect on flavor or appearance. Methods to create and encapsulate liquid aromas and measure aroma release are presented along with comparative results, capsule microscopy images, and potential to adapt this system to other hot foods and beverages.