Macrowine 2021
IVES 9 IVES Conference Series 9 Effect of concentration and competition between different fungicide residues on the adsorption efficiency of activated vegetal fibres for treatment of wine

Effect of concentration and competition between different fungicide residues on the adsorption efficiency of activated vegetal fibres for treatment of wine

Abstract

Vineyards are strongly exposed to fungal diseases, attacks from insects and competition with weeds. Most treatments used on grape vines contain synthetic active substances, which may be transferred to the wine. Such pesticides have a negative image because many active substances are potential health hazards. A specific oenological treatment allowing the reduction of pesticide residues in wine based on activated vegetable fibres (AVF) is under examination by the International Organisation for Vine and Wine. This technique works efficiently and alters the wine only little (Lempereur et al. 2014). The purpose of this study was to investigate the difference in adsorption efficiency of the active substances most used by Swiss winegrowers. Furthermore, effects of concentration and competition between the different active substances in the adsorption efficiency of AVF were investigated. The concentration and competition trials were carried out using white wine without pesticides allowing to artificially spike six active substances. The investigation of the concentration effect led to the Freundlich isotherms allowing the calculation of the adsorption capacities of Fenpropidin k = 1816μg/g fiber and Fluopyram k = 556μg/g of fibre. This showed that the rate of reduction of these active substances is not related to the initial concentration, but remains stable over the tested range. The results of the competition trial indicate no interaction between different active substances present in a solution for the absorption by AVF. Indeed, it was not possible to show significant differences between the reduction rate of pesticides in a wine containing a cocktail of six active substances and wines containing only one of the active substances. Our results also confirm that the reduction rate depends on the active substance. Among the tested substances, there are three different efficiency classes: Mandipropamid, Cyprodinil and Fenpropidin with reduction rates between 80-100%, Fludioxonil and Fluopyram with rates between 50-80% and Iprovalicarb with a rate under 50%. This classification confirms the results of previous pre-industrial trials (Lempereur et al. 2014), except for Fenpropidin and Fluopyram that were never tested before. These experiments show the potential of AVF for active substances untested so far such as Fluopyram and Fenpropidin. Trials are currently under way to compare the efficiency of AVF between laboratory and pre-industrial conditions and to investigate the sensory impact on the wine, particularly the perception threshold of the AVF and their impact on the colloidal balance of the wine.

Publication date: May 17, 2024

Issue: Macrowine 2016

Type: Poster

Authors

Michel Reynolds*, Carole Koestel, Céline Louaisil, Johannes Rösti, Magali Grinbaum, Valérie Lempereur

*Agroscope

Contact the author

Tags

IVES Conference Series | Macrowine | Macrowine 2016

Citation

Related articles…

Impact of smoke exposure on the chemical composition of grapes

Vineyard exposure to smoke can lead to grapes and wine which exhibit objectionable smoky and ashy aromas and flavours, more commonly known as ‘smoke taint’ [1, 2]. In the last decade, significant bushfires have occurred around the world, including near wine regions in Australia, Canada, South Africa and the USA, as a consequence of the warmer, drier conditions associated with climate change. Considerable research has subsequently been undertaken to determine the chemical, sensory and physiological consequences of grapevine exposure to smoke. The sensory attributes associated with smoke-tainted wine have been linked to the presence of several smoke-derived volatile phenols, such as guaiacols, syringols and cresols [2].

Analysis of the oenological potentials of different oak forests in Hungary

Like France, Hungary has many oak forests used for making barrels since many years. But if the differences between the woods of the North, the East and the South-West forests of France are well known, this is probably not the case of Hungarian forests. However taking into account the essential differences of climates and soils, differences must be significant and the general name “Hungarian oak” must not have any real meaning. We have studied precisely (determination of concentrations of volatile and non-volatile wood compounds, anatomical criteria, measurement of antioxidant capacity) of oaks collected from northeastern Hungary and others collected from the Danube valley in the northwest of the country.

Capture depletion of grapevine DNA: an approach to advance the study of microbial community in wine

The use of next-generation sequencing (NGS) has helped understand microbial genetics in oenology. Current studies mainly focus on barcoded amplicon NGS but not shotgun sequencing, which is useful for functional analyses. Since the high percentage of grapevine DNA conceals the microbial DNA in must, the majority of sequencing data is wasted in bioinformatic analyses. Here we present capture depletion of grapevine whole genome DNA.

The effect of Nitrogen and Sulphur foliar applications in hot climates

ine nitrogen deficiency can negatively influence the aroma profile and ageing potential of white wines. Canopy management can alter vine microclimate, affect the nitrogen availability and influence the response of leaf senescence. Increasing the nitrogen availability to vines can increase the Yeast Assimilable Nitrogen (YAN) levels in harvested fruit and wine. Studies show that foliar nitrogen and sulphur applications at véraison, on low YAN Sauvignon blanc grapes have an effect on the level of amino acids (Jreij et al. 2009) and on S-containing compounds such as glutathione and thiols (Lacroux et al. 2008), which in turn can influence the formation of major volatiles and the aroma profile of the wine.

Phenolic profiles of minor red grape cultivars autochthonous from the Spanish region of La Mancha

The phenolic profiles of little known red grape cultivars, namely Garnacho, Moribel and Tinto Fragoso, which are autochthonous from the Spanish region of La Mancha (ca. 600,000 ha of vineyards) have been studied over the consecutive seasons of years 2013 and 2014. The study was separately performed over the skins, the pulp and the seeds, and comprised the following phenolic types: anthocyanins, flavonols, hydroxycinnamic acid derivatives (HCADs), total proanthocyanidins (PAs) and their structural features. The selected grape cultivars belong to the Vine Germplasm Bank created in this region in order to preserve the great diversity of genotypes grown in La Mancha.