Rotwein unter Hochspannung: Mehrjährige Qualitäts- Untersuchung mit Gas-Discharge-Visualisation (GDV)

Summary

We investigated whether we can detect any differences in red wines produced either
by bio-dynamic or by standard organic agriculture. We used standard methods to
investigate the quality of the wines and Gas-Discharge-Visualisation (GDV) method to
investigate a holistic quality of the wines. With the GDV-method, samples are exposed
to high voltage. The halo-like gas discharge caused by a burst of electron emission of
the sample is captured by a digital camera underneath a transparent, dielectric surface.
The wine samples measured originate from an On-Farm experiment in South of
France with two separately managed but neighbouring blocks (same soil and climate
conditions): bio-organic and bio-dynamic. Apart from the use of bio-dynamic preparations,
plant protection and fertilization was the same in both blocks. The vinification of
the sampled grapes was made in two replicates which were analysed separately.
During the three years of examination, the bio-dynamic samples did not reveal significant
differences when assessed with standard methods (sensory triangle test, polyphenol
analysis etc.). However, with GDV measurements the values for the imageparameter
“mean intensity” were mostly higher for the wines from bio-dynamically
produced grapes. In a „mixed effect model“ (GDV-parameter „mean intensity“ as
dependent variable, replication und cultivation-system as fix and year as random
effect) the difference was statistically significant. We conclude that the GDV-method
has an interesting potential to detect very sensitively differences in food attributes.
However, in order to interpret the results in terms of consumer-relevant quality further
research is needed.