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Extractive fermentation of aroma with supercritical CO 2
Author(s) -
Fabre Cathy E.,
Condoret JeanStéphane,
Marty Alain
Publication year - 1999
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/(sici)1097-0290(19990820)64:4<392::aid-bit2>3.0.co;2-g
Subject(s) - aroma , supercritical fluid , fermentation , chemistry , supercritical fluid extraction , food science , chromatography , organic chemistry
Abstract This work deals with the feasibility of achieving an extractive fermentation of 2‐phenylethyl alcohol, the rose aroma, coupling fermentation with Kluyveromyces marxianus and supercritical carbon dioxide (SCCO 2 ) extraction. The extractive process is, in this case, of special interest due to the strong yeast inhibition by 2‐phenylethyl alcohol. First results confirmed that direct SCCO 2 extraction is not possible, due to a drastic CO 2 effect on cell viability. It is therefore necessary to perform cell separation prior to the extraction. Aroma extraction conditions from a synthetic mixture were then optimized, a pressure of 200 bar and a temperature in the range 35–45°C being chosen. Under these conditions, the distribution coefficient K d is 2 times higher than during the extraction using a conventional organic solvent, n ‐hexane. Using a simple model of aroma partition between aqueous and SCCO 2 phases, the parameters of a continuous extraction from a synthetic broth were defined. The two substrates, glucose and phenylalanine, are not extracted whatever the conditions. As predicted by the model, more than 90% of 2‐phenylethyl alcohol can be extracted, while the extraction of ethanol, the second main product, can be easily tuned with respect to operating conditions, as a function of its influence on the fermentation. Finally, the feasibility of the aroma recovery using two depressurization steps at the outflow of the extraction vessel was demonstrated; 97% of the extracted aroma was recovered, and a mass purity of 91% was achieved. © 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 64: 392‐400, 1999.