ŻYWNOŚĆ. Nauka. Technologia. Jakość, 2004, 3 (40), 77 - 86

AGNIESZKA WOJTYŚ, TOMASZ JANKOWSKI

THE EFFECT OF TEMPERATURE ON THE PERMEATION RATE OF SOME SELECTED ESSENTIAL OILS INTO BAKER’S YEAST CELLS

S u m m a r y

The influence of temperature on the permeation of orange peel and peppermint essential oils into baker’s yeast cells was investigated. The oils were mixed by agitation with an aqueous suspension of yeast cells at four temperatures (25^o, 40^o, 50^o, and 70^oC). After centrifuging, the yeast cells were washed with distilled water and freeze dried. The oil content in the cells was analysed by the gas chromatography after the water/ethanol extraction procedure. The oils, owing to their hydrophobic nature, passively diffused across the cell membrane and remained in the cells after having been freeze-dried. The rate of their diffusion into yeast cells increased along with the growing process temperature; it was significantly higher for the peppermint than for the orange peel oil. The maximum oil content in the freeze-dried cells was: as for the orange peel: 24% of total solids, and as for the peppermint oil: 43% of total solids; it did not depend on the process temperature.

Key words: orange peel oil, peppermint oil, flavour encapsulation, Saccharomyces cerevisiae