An extract of black radish (Raphanus niger) may provide a natural alternative to sulphur dioxide for viticulturists, according to a new study from Greece.
Writing in the journal Journal of Food Composition and Analysis, Maria-Ioanna Salaha and her co-workers from the Wine Institute at the National Agricultural Research Foundation (NAGREF) and the Technological Educational Institution (TEI) of Athens report that the natural alternative may help reduce the quantity of sulphur dioxide used in wine making.
According to the researchers, the use of sulphur dioxide has recently come under review due to health concerns. As such, European Union regulations now require that wines must prominently display on the label the presence of total sulphites in excess of 10 mg/l.
“Winemakers are therefore faced with the problem of finding a viable substitute for the antioxidant and antiseptic action of sulphite in winemaking,” explained the researchers.
An alternative product, described by Salaha and her co-workers as being of “biological origin, and contain[ing] mainly black radish (Raphanus niger) extract and ascorbic acid”, was tested for its potential to reduce or replace the sulphur dioxide content of wine.
The research is indicative of a wider issue in the food industry of seeking natural alternatives to synthetic or “chemical” additives. Indeed, the issue of oxidation in food, leading to organoleptic deterioration in taste, colour and texture, is a key concern for food formulators.
The industry as a whole is increasingly seeking natural solutions rather than artificial additives, such as like butylhydroxyanisole (BHA) and butylhydroxytoluene (BHT), to extend the shelf life of milder-tasting products.
Wines produced from four different red vinifications using the black radish extract with or without sulphur dioxide. Results showed that “commercially acceptable red wines were produced” in all cases, said the researchers.
The anthocyanin content of the wines was not affected by the use of the black radish extract or the sulphur dioxide, but a higher total and individual anthocyanin content was observed when sulphur dioxide was used alone.
The same was observed for the total phenol and flavanol content of the wine. Despite such observable differences, the wines were still considered to be within in the “range expected for commercially acceptable red wines”, said the researchers.
While the new additive may not lead to the removal and replacement of sulphur dioxide, the researchers noted that it could lead to partial substitution of the contentious dioxide.
“The components of this alternative product have acknowledged beneficial properties in contrast with potential health problems associated to sulphur dioxide. In this way, the quantities of SO2 added during winemaking could be reduced following the need for the production of a ‘healthier’ wine,” they said.
Source: Journal of Food Composition and Analysis
December 2008, Volume 21, Issue 8, Pages 660-666
“A natural alternative to sulphur dioxide for red wine production: Influence on colour, antioxidant activity and anthocyanin content”
Authors: M.-I. Salaha, S. Kallithraka, I. Marmaras, E. Koussissi, I. Tzourou