The Measurement of Free and Total Peppermint Oil in a Yeast-based Micro-encapsulation System

Fluid Technologies' Micap™ is a yeast-based micro-encapsulation system for volatile food flavours and other components including pesticides and pharmaceuticals. The yeast used for encapsulation is grown continuously in large fermenters, forming 8-12 um diameter biocapsules. The level of encapsulation can be up to 60% w/w dry weight of yeast. Following spray drying the end product is a free flowing dry powder. The level of encapsulation is measured by solvent extraction with analysis by GC-FID or GC-MS. However, further characterisation of the encapsulates can be carried out by thermal desorption using difficult matrix introduction (DMI) to measure the total volatile present or measuring the level of volatile surface residues by using SPME and GC-MS, both of which can be automated using the Focus Robotic Sample Processor with the DTD and SPME options. Presented here are the initial results for encapsulated peppermint oil.