Pulsed electric field-assisted fermentation of Hanseniaspora sp. yeast isolated from Lebanese apples

• Published in: Food research international 2020-03, Vol.129, p.108840-108840, Article 108840
• Main Authors: Al Daccache, Marina, Koubaa, Mohamed, Maroun, Richard G., Salameh, Dominique, Louka, Nicolas, Vorobiev, Eugène
• Format: Article
• Language: English
• Subjects: Alcoholic Beverages; Biotechnology; Chemical and Process Engineering; Electrophysiological Phenomena; Engineering Sciences; Fermentation; Food and Nutrition; Fruit - microbiology; Hanseniaspora - metabolism; Hanseniaspora sp; Life Sciences; Malus - microbiology; Pulsed electric field; Stimulation
• ISSN: 0963-9969; 1873-7145
• DOI: 10.1016/j.foodres.2019.108840

[Display omitted] •Stimulation of Hanseniaspora sp. yeast using pulsed electric fields (PEF) during fermentation.•Application of a PEF intensity range of 72–285 V/cm during both Lag and Log phases of yeast growth.•The maximal yeast growth rate was obtained using electric field strength of 285 V/cm.•Faster consumption of glucose in the medium was observed for PEF-assisted fermentation.•Lag and early exponential phase was more sensitive to stimulation than Log phase. Hanseniaspora sp. yeast was stimulated using pulsed electric field (PEF) during the different fermentation phases. The impact of PEF parameters on the growth rate and substrate consumption was studied. The PEF intensities chosen for this study were mainly in the range of 72–285 V cm−1. A PEF treatment chamber was designed for this study with a ratio of 1:50 between the volume of the fermenter and the volume of the chamber. It allows the recycling of the culture medium using a peristaltic pump, and the yeast treatment by PEF during the fermentation. The continuous circulation of the medium allows avoiding the increase of the temperature inside the fermenter, the cell aggregation, as well as the agitation and the scale-up issues that are associated with the PEF treatment of the entire volume in batch mode. The maximal yeast growth rate was obtained using an electric field strength of 285 V cm−1 applied during both Lag and early exponential phase, and Log phase. This observation was accompanied by a faster consumption of glucose in the medium during the fermentation. Besides, the sensitivity of Hanseniaspora sp. yeast to PEF treatment was more pronounced during the Lag and early exponential phase than the Log phase. The results obtained exposed the great benefit of stimulating Hanseniaspora sp. yeast using moderate PEF as it reduces the fermentation time along with increasing the biomass concentration.