Monitoring of Lactic Fermentation with a Coupling Electronic Nose and Gas Chromatography

In this work, the performance of dehydratation-desalcoholization system based on an electronic nose coupled to gas chromatography was tested. The system was used for monitoring the volatile compounds produced during a lactic fermentation with a heterofermentative bacteria (Lactobacillus fermentum Ogi E1). The monitoring was carried out with dehydratation and desalcoholization or dehydratation only, on the basis of low ethanol concentration produced by this bacteria. In the first case, fermentation head-space analyses showed low signals from each gas sensor, then the principal components analyses (PCA) resulted confused. However with the only dehydratation system, the electronic nose was able to detect some volatile compounds during bioprocess. The PCA showed a single distribution, permitting to conclude that principal component 1 represented the ethanol concentration. The system is appropriate to monitor some parameters during the fermentations process as ethanol, lactate and biomass concentration.