terclim by ICS banner
IVES 9 IVES Conference Series 9 IMPACT OF RHIZOPUS AND BOTRYTIS ON WINE FOAMING PROPERTIES

IMPACT OF RHIZOPUS AND BOTRYTIS ON WINE FOAMING PROPERTIES

Abstract

A lot of work has been done on the impact of Botrytis on the foam of sparkling wines. This work often concerns wines produced in cool regions, where Botrytis is the dominant fungal pathogen. However, in southern countries such as Spain, in particularly hot years such as 2022, the majority fungal pathogen is sometimes Rhizopus. Like Botrytis, Rhizopus is a fungus that produces an aspartic protease. The aim of this study was therefore to determine the foaming properties of wines produced with a synthetic must contaminated by a Rhizopus or Botrytis culture. In order to confirm the identification of the fungal strain, the D1-D3 domains of the 28S rRNA gene were amplified and sequenced. BLAST search indicated 100% identity with a reference strain of Rhizopus lyococcus (CBS 320.35).

The complete experimental design presents 12 modalities (AF in triplicate, i.e. 36 bottles). The fungal isolates of Botrytis cinerea (B. c.) and Rhizopus lyococcus (R. l.) were cultured using a modified version of the method described by Gimenez et al. (2022). Alcoholic fermentations (AF) were performed in 500mL glass bottles from synthetic grape must supplemented or not with 50 mg/L of epicatechin. The yeast strain S. cerevisiae Lalvin EC1118 (Lallemand) was used for the AF process. To examine the impact of the pathoge- nic fungi, 10% (v/v) of B.c. or R.l. culture were added (separately) to the model grape juice. Furthermore, two different concentrations of L-malic acid were added to the fermentation media creating two sets of conditions : 2g/L of L-malic acid (pH=3.5) and 6 g/L of L-malic acid (pH=3). The results of the wines with fungus were compared to those of the control wines obtained without fungus.

The results of this study show that the presence of Rhizopus in the must significantly or highly significantly degrades the foamability and foam stability of the wines (foam measured with the KRUSS DFA100 equipment). The analysis of the protein composition by SDS-PAGE clearly shows a degradation of the yeast proteins by the fungal proteases of Rhizopus. Surprisingly, the Botrytis strain used did not affect the foam of the wines. These differences in proteolytic activity are confirmed by using BSA as a subs- trate: the Rhizopus culture degrades the 500 mg/L BSA in a few minutes, whereas the BSA degradation by the Botrytis culture remains considerably lower despite the longer culture of the fungus. Finally, the presence of epicatechin did not affect the wines’ foaming properties.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Richard Marchal¹, Candela Ruiz De Villa Sardón², Arnau Just Borràs², Nicolas Rozès², Fernando Zamora Marín², Joan-Miquel Canals Bosch², Thomas Salmon¹, José Francisco Cano Lira³, Jacques-Emmanuel Barbier4, Sabine Gognies¹

1. Université de Reims Champagne-Ardenne, Faculté des Sciences, Laboratoire d’Oenologie, 51687 Reims CEDEX 02, France
2. Universitat Rovira i Virgili, Facultat d’Enologia, Campus Sescelades, 43007 Tarragona, Spain
3. Un+iversitat Rovira i Virgili, Mycology, Environmental Microbiology Unit, Medicine Faculty / Oenology Faculty,  Sant Llorenç 21, 43201-Reus, Spain
4. Institut Œnologique de Champagne – ZI de Mardeuil – 51201 Épernay Cedex, France 

Contact the author*

Keywords

wine foam, Rhizopus, yeast proteins, aspartic protease

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

CHARACTERIZATION OF THE VOLATILE COMPOUNDS PROFILE OF COMMERCIAL GRAPPAS OBTAINED FROM THE POMACE OF AMARONE WINES

Grappa is a traditional Italian alcoholic beverage, with an alcohol content generally between 40-60% vol., obtained from the distillation of grape pomace used for the production of wine. Grappa are often aged in wooden barrels. There are various types of grappa: young, aromatic, aged, extra-aged depending on whether the distillate comes from aromatic vines or is aged in wooden barrels for shorter or longer periods. There is also flavored grappa if herbs, fruit or roots are added. All this makes it an extremely heterogeneous product both from an organoleptic and compositional point of view.

USING CHECK-ALL-THAT-APPLY (CATA) TO CATEGORIZE WINES: A DECISION-MAKING TOOL FOR WINE SELECTION

Bordeaux is the largest appellation vineyard in France. This contrasting vineyard with varied terroirs offers all styles of wine, resulting from the blending of several grape varieties. If these different profiles make the renown of Bordeaux wines, it can appear as a constraint when the aim is to study Bordeaux wines in their diversity. The selection of a representative sample can be performed by a sensory analysis carried out by trained panelists or by wine professionals, which can take several forms: consensus among experts, conventional descriptive analysis, typicality or quality evaluation. However, because of time, economic, and logistical constraints, these methods have limited applications. As an alternative to classical descriptive analysis, more intuitive methods that do not require training have been proposed recently to describe wines using an expert panel such as Napping, Free Choice or Flash Profiling, CATA or RATA.

Overhead spray water treatment as a mitigation strategy for reducing vine stress and preserving grape quality during heatwaves

Changes in climate have been influencing the quality of wine grapes worldwide. The impact of extreme climate events over short periods is increasingly recognized as a serious risk to grape quality and yield quantity. In this study the mitigation effects of a pulsed water spray on vine canopy during heatwave events has been evaluated for maintaining vine condition during the growing season and grape quality. Vines of three varieties (Malbec, Bonarda, and Syrah) under drip irrigation in the UNCuyo experimental vineyard were treated with an overhead pulsed water spray.

NEW TOOL FOR SIMULTANEOUS MEASUREMENT OF OXYGEN CONSUMPTION AND COLOUR MODIFICATIONS IN WINES

Measuring the effect of oxygen consumption on the colour of wines as the level of dissolved oxygen decreases over time is very useful to know how much oxygen a wine is able to consume without significantly altering its colour. The changes produced in wine after being exposed to high oxygen concen-trations have been studied by different authors, but in all cases the wine has been analysed once the oxygen consumption process has been completed. This work presents the results obtained with the use of an equipment designed and made to measure simultaneously the level of dissolved oxygen and the spectrum of the wine, during the oxygen consumption process from saturation levels with air to very low levels, which indicate the total consumption of the dosed oxygen.

EXPLORING THE METABOLIC AND PHENOTYPIC DIVERSITY OF INDIGENOUS YEASTS ISOLATED FROM GREEK WINE

Climate change leads to even more hostile and stressful for the wine microorganism conditions and consequently issues with fermentation rate progression and off-character formation are frequently observed. The objective of the current research was to classify a great collection of yeast isolates from Greek wines based on their technological properties with oenological interest. Towards this direction, fourteen spontaneously fermented wines from different regions of Greece were collected for further yeast typing. The yeast isolates were subjected in molecular analyses and identification at species level.