Encapsulation of limonene in yeast cells using the concentrated powder form technology

Abstract Spent yeast cells are gained as by-products of beer and bioethanol production. Their capability as natural carrier material is underestimated. The concentrated powder form (CPF) technology is a high-pressure spray process suitable for loading a carrier material with flavours under particularly gentle process conditions, e.g. an inert gas atmosphere and low temperatures. In this study, a new process for the encapsulation of limonene, combining the gentle CPF process and emptied yeast cells as carrier material, is presented. Yeast cells are loaded with limonene and water. The water is necessary to open the pores of the cell wall and therefore to allow the limonene to enter the cell. Yeast cells with limonene contents of up to 27.4 wt-% were produced. Remarkably, the produced limonene-filled yeast cells withstand, after drying, harsh washing with hexane without losing limonene in significant amounts. SEM pictures show that the yeast cell surfaces are intact after processing.