What effect does the treatment have on the chemical composition
Chemical composition refers to the acidity (pH level), residual sugar (RS), volatile acidity (VA), titratable acids (TA) and alcohol content of the wine.
Tests on wines treated with SurePure photopurification indicated no changes in the routine chemical analysis of the wines (alcohol, TA, pH, VA, etc). The treatment had no effect on the alcohol, extract, reducing sugar, volatile acidity, pH, and titratable acidity.
What effect does the treatment have on the colour of the wine?
The intensity of brown colour (Abs 420nm) and red colour (Abs 520nm) were measured in the wines.
The colour intensity (420 + 520) gives an indication of the density of the wine colour. Higher values indicate more intensely-coloured wines.
The colour hue (420/520) gives an indication of the hue (tint) of the colour. Lower values are better and indicate less brown and more intense red colouration.
Colour measurements of control and SurePure treated wines indicated insignificant changes with no loss in colour or increase in browning from oxidation during the treatment.
Does the treatment prevent wine from pinking?
The development of a pink colour in white wine is known as pinking. Flavene and Leucoantosionine are converted into brown pigments in the presence of oxygen in the wine.
When flavene is diverted into red flavenesalt, it gives the wine a pink colour. This usually happens if the wine is over-exposed to oxygen, especially during filtration and bottling.
Winemakers usually use PVPP or casein to get rid of pinking. In most cases, however, the wine is merely exposed to sunlight until the pink colour disappears, with the attendant risk of microbiological infection. The SurePure technology can be used to assist with this problem.
Wine, especially red wine, has phenolic compounds that absorb UV light at 254nm. What effect does it have on the oxidation stability of the wine?
The treatment induces no changes in the wine colour and polyphenol levels. It is a closed and pressurized system, which means there is no place for oxygen to enter the system and therefore cannot oxidize the wine during treatment. The treatment has no effect or change on the phenols present in the wine.
If the microbial count in your wine is reduced, will the VA also be reduced?
The effect of the SurePure treatment on the microbial levels in the wines is remarkable. All wines treated showed significantly lower levels of yeasts and bacteria. The level of reduction in microbial counts depended on the microbiological load and the amount of exposure during the treatment.
However, photopurification cannot eliminate VA in the wine. If wine is treated in an early stage of the winemaking process, VA will be prevented from forming.