Macrowine 2021
IVES 9 IVES Conference Series 9 Effect of nanofiltration on the chemical composition and wine quality

Effect of nanofiltration on the chemical composition and wine quality

Abstract

In Enology the conventional processes of filtration for clarification and stabilization are giving place to alternative membrane processes, including nanofiltration (NF). Furthermore, the increased alcohol content in wines recorded in recent years became an important issue for all the main wine producing countries. Among techniques available to the wine industry to reduce the ethanol content, NF is certainly one of the newest. This study is focused on the evaluation of NF influence on wine physical-chemical composition, including mineral content, which in accordance to our best knowledge is a novelty. NF essays at laboratorial scale using a cellulose acetate membrane prepared and characterized for this purpose were carried out, at a first stage with model solutions (to better understanding of wine NF results) and later with white and red wines from three Portuguese Denominations of Origin (DO), Dão, Palmela and Óbidos. Regarding model solutions trials, high rejection to tartaric acid and low rejection to ethanol were observed. Wines and respective NF fractions were evaluated in terms of physical-chemical composition, comprising summary analysis parameters, organic acids, total anthocyanins, total phenols index, total polysaccharides and multi-elemental composition. As expected, ethanol was preferentially permeated by the membrane. Rejections to tartaric, lactic, malic and acetic acids, phenolic compounds and mineral elements were in general very high. Concerning polysaccharides a complete retention was verified. For the majority of chemical compounds concentrations in final feed increased with NF treatment, due to water and ethanol removal. Considering NF use for wine dealcoholisation, alcoholic strength in final feed can be reduced by reposition of the permeated water, after separation by distillation.

Publication date: May 17, 2024

Issue: Macrowine 2016

Type: Poster

Authors

Sofia Catarino*, António Curvelo Garcia, Cíntia Moreira, Jorge Ricardo-Da-Silva, Maria de Pinho, Raul Bruno de Sousa

*ISA

Contact the author

Tags

IVES Conference Series | Macrowine | Macrowine 2016

Citation

Related articles…

Measurements of the oxygen dissolved in white wines elaborated in barrels without to open the bung of the barrels

Bases on oxoluminescence, we have developed an innovative device for measuring dissolved oxygen in wines in barrels without opening the bung. This system is directly inserted into the wood during the barrel elaboration and can be positioned at different locations of the barrel (the head, the hull …). During two successive vintages we have used this device notably to follow the oxygen dissolved of whites wines elaborated in barrels. This allowed us initially to monitor the oxygen levels of the harvest to bottling the whole elaboration process in barrels of white wines without using techniques of measurement suitable to modify the real values in wines (opening the bung to plunge an oximeter).

Comparison of various storage conditions to preserve polyphenols in red-grape pomace

Red grape pomace, a waste from wine production, can be valorised by extracting polyphenols, high-added value compounds used in cosmetics or oenology. For use at an industrial level, using green extraction techniques, pomace need to be stored before being processed. The aim of this study is to test various storage conditions in order to maintain high level of polyphenols over 180 days, while keeping storage cost economically interesting. In a first step, different storage conditions (ambient temperature or cooled (4°C) temperature, anaerobic (saturation with N2) or aerobic conditions, and addition of sulphur dioxide (SO2)) were compared on small samples (1 kg) packed in plastic pockets. The quality of storage was assessed by following the optical density of the pomace extract at 280 nm (DO 280 expressed as mg/l eq gallic acid), which is an indication of the amount of remaining extractable polyphenols.

Foam characteristics of white, rosé and red sparkling wines elaborated by the champenoise method

Contribution Foam is the characteristic that differentiates sparkling wines from still wines, being the first sensory attribute that tasters and consumers perceive and that determines the final quality of sparkling wines [1]. The foaming properties mainly depend on the chemical composition of wines [2-3], and different factors involved in wine composition will have an effect on foam quality. In Spain, the sparkling wine market focuses on the production of white and rosé sparkling wine, with very low production of red sparkling wines. However, this type of wines is elaborated in countries like Australia, South-Africa, Argentina, Italy or Portugal, with a great acceptance by consumers. No studies on the foaming characteristics of red sparkling wines have been found.

Light-struck taste in white wine: enological approach for its prevention

Light-struck taste is a defect prevalent in white wines bottled in clear glass light-exposed for a considerable amount of time leading to a loss of color and appearance of sulfur-like odors. The reaction involves riboflavin (RF), a highly photosensitive compound that undergoes to intermolecular photoreduction by the uptake of two electron equivalents from an external donor, the methionine. The reaction includes different steps forming methional which is extremely unstable and decomposes to methane thiol and acrolein. The reaction of two molecules of methane thiol yields dimethyl disulfide. Methane thiol is highly volatile, has a low perception threshold (2 to 10 µg/L in wine) and confers aroma-like rotten eggs or cabbage.

Evaluating South African Chenin blanc wine styles using an LC-MS screening method

Sorting Chenin blanc is one of the most important white wine cultivars in South Africa. It has received a lot of attention and accolades in the past years and more research than ever is dedicated to this versatile cultivar. According to the Chenin blanc association of South Africa, there are three recognized dry wine styles, Fresh and Fruity (FF), Rich and Ripe Unwooded
(RRU), and Rich and Ripe Wooded (RRW). They are traditionally established with the aid of expert sensory evaluation, but the cost and the (subjective) human factor are aspects to be taken into account. A more objective and possibly robust way of assessing and attributing these styles can be the use of chemical analysis.