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…

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).

Assessing the effect of oak derived aromas on mouthfeel perception in Chardonnay wine

Mouthfeel is an important quality parameter for Chardonnay wines, particularly those aged in oak. While research on mouthfeel has traditionally focused on the impact of non-aromatic compounds, the role of aroma compounds has largely been over looked. However, in wine as well as other food interactions between retronasal aroma and mouthfeel have been noted. The goal of this research was to investigate the impact of wine aroma on the perception of mouthfeel. Because of the importance of oak aging in the development of Chardonnay mouthfeel, the impact of oak aromas on perceived mouthfeel was explored. Aroma compounds associated with oak (ethyl palmitate, eugenol, furfural, isoeugenol, syringaldehyde, vanillin and whiskey lactone) were added to two different Chardonnay wines; one with no oak influence and one fermented in neutral oak. Low and high concentrations of the compounds were added based on concentrations typically found in barrel aged Chardonnay wine.

Influence of methyl jasmonate foliar application to vineyard on grape volatile composition over three consecutive vintages

An alternative to improve grape quality is the application to the vineyard of elicitors. Although these compounds were first used to increase resistance of plants against pathogens, it has been found that they are also able to induce mechanisms involved in the synthesis of phenolic compounds and some amino acids. However, researches about the influence of elicitors on grape volatile composition are scarcely. Therefore, the aim of this work was to study the influence of methyl jasmonate (MeJ) foliar application on grape aroma composition over three consecutive vintages. MeJ was applied to Tempranillo grapevines at a concentration of 10 mM in 2013, 2014, and 2015 years. Control plants were sprayed with water.

Metabolomics of grape polyphenols as a consequence of post-harvest drying: on-plant dehydration vs warehouse withering

A method of suspect screening analysis to study grape metabolomics, was developed [1]. By performing ultra-high performance liquid chromatography (UHPLC) – high-resolution mass spectrometry (HRMS) analysis of the grape extract, averaging 320-450 putative grape compounds are identified which include mainly polyphenols. Identification of metabolites is performed by a new HRMS-database of putative grape and wine compounds expressly constructed (GrapeMetabolomics) which currently includes around 1,100 entries.

Sensory definition of green aroma concept in red French wines. Evidence for the contribution of novel volatile markers

The aromatic complexity of a wine results from the perception of the association of volatile molecules and each aroma can be categorized into different families. The “green” aromas family in red wines has retained our attention by its close link with the fruity perception. In that study, the “green” olfactory concept of red wines was considered through a strategy combining both sensory analysis and hyphenated chromatographic techniques including HPLC and MDGC (Multidimensional Gas Chromatography). The aromatic space of this concept was specified by lexical generation through a free association task on 22 selected wines by a panel of wine experts. Then, 70 French red wines were scored on the basis of the intensity of their “green” and “fruity” attributes.