Partial Dealcoholization of Red Wines by Membrane Contactor Technique: Effect on Sensory Characteristics and Volatile Composition

Abstract

Recently, the European Union regulation has fixed the maximum permitted dealcoholization level at 2 %; however in some cases, higher dealcoholization levels could be necessary. It is assumed that higher levels of dealcoholization could negatively affect the organoleptic quality of wine, but little data on this item is available. In the present study, two red wines (cv. Aglianico) with different initial alcohol contents (15.37 and 13.28 % v/v), were partially dealcoholized at three levels (-2, -3, -5 % v/v), by a polypropylene hollow fibre membrane contactor apparatus. In order to evaluate if dealcoholized wines differed from the untreated ones, triangle sensory tests were performed. Both -2 % wines were not perceived as different from the standard wines, while both -5 % wines were different. Sensory profiles and overall quality ranking were obtained by a selected and trained panel. Dealcoholization caused a modification of the sensory profiles, and the greatest differences were found after a dealcoholization of 5 % v/v. The most decreased olfactory notes were those of "Red fruits", "Cherry" and "Spicy", which is very important for the sensory quality of red wine. Concerning taste, both -5 % dealcoholized wines were more astringent than the correspondent untreated ones. Slighter differences were found for the other degrees of dealcoholization. The analysis of the volatile compounds, both free and glycoconjugated was performed by solid-phase extraction and gas chromatography mass spectrography analysis. While the composition of the glycoconjugated volatile fraction was almost not affected, many free compounds were decreased, most of all esters and alcohols, with an increasing amounts as the level of dealcoholization raised

Alcohol Reduction by Physical Methods

“…Nevertheless there was no clear tendency in terms of preference. That is in line with other sources [39,40].…”

“…A comparative study of the different physical methods helps to assess what technology is more gentle in terms of wine quality. Several sources report that a wine with an alcohol reduction by 2 vol.% is not differed from the initial wine [2,3,14,39,41,52,[56][57][58].…”

“…That proves that the preferences in terms of alcohol content in wine are not uniform. Instead of small changes in terms of alcohol contents, it could be more interesting to clearly change wine style, thus creating wines that are favored by customers who prefer lighter wines [21,31,39,41,51,57].…”

Fortification and Elevated Alcohol Concentration Affect the Concentration of Rotundone and Volatiles in Vitis vinifera cv. Shiraz Wine

“…No significant differences were observed in wine colour density and degree of red pigment colouration amongst all experimental groups. Few researchers have compared anthocyanins and phenolics content between non-fortified and fortified wine, but many have investigated the influences of alcohol removal on the chemical composition of wine with inconsistent results [29][30][31]. Motta, Guaita, Petrozziello, Ciambotti, Panero, Solomita and Bosso [30], observed higher concentration of total anthocyanins, flavonoid and colour intensity in treatments with 5% of alcohol removal.…”

Alcohol reduction in red wines by technological and microbiological approaches: a comparative study

“…These post‐fermentation strategies, however, have drawbacks, because they are difficult to perform, have high cost and affect the composition and sensory attributes of the wine. Nevertheless, the effects are acceptable in partially dealcoholised wines when the ethanol concentration is reduced by 2% v/v (Diban et al , Lisanti et al ).…”