TITLE:
Utilisation of a Portable Electronic Nose, NeOse Pro, to Follow the Microbial Fermentation of a Yoghurt
AUTHORS:
Yann Demarigny, Elodie Legrand, Julia Sanchez, Arnaud Hallier, Nathalie Laurent, Sami Slimani, Thierry Livache, Daniel Picque
KEYWORDS:
NeOse Pro, Yoghurt, GC/MS, Aroma
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.12 No.1,
January
28,
2021
ABSTRACT: Yoghurt is fermented milk which results from the exclusive action of Lactobacillus delbrueckii subsp bulgaricus and Streptococcus thermophilus. However, a disruption of
the bacterial growth can lead to significant industrial losses. Currents
monitoring methods, based on the checking of the pH during the fermentation
step are not always satisfactory. The NeOse Pro system, a portable electronic
nose, is a mean to obtain immediately aromatic profiles. In this work, we
applied this technology to the yoghurt ecosystem, a highly hydrated product.
The profiles obtained allowed us to discriminate yoghurts before and after
fermentation. In detail, the discrepancy between the two bacteria cultured
alone was slight. It was also the case when we compared different initial
bacterial ratios. However, two different mixes of bacteria led to clearly
distinguishable profiles. A GC/MS analysis performed on products fermented 7 h
allowed us to explain the detection of acetaldehyde by the stimulation of some
captors of the apparatus. NeOse Pro is so convenient to study the fermentation
of yogurt.