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…

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.

EFFECT OF FERMENTATION TEMPERATURE GRADIENT AND SKIN CONTACT ON ESTER AND THIOL PRODUCTION AND TROPICAL FRUIT PERCEPTION IN CHARDONNAY WINES

Wines with tropical fruit aromas have become increasingly more available1,2. With increased availability of different wine styles, it has become important to understand the compounds that cause the fruity aromas in wine. Previous work using micro fermentations showed that fermentation temperature gradients and time on skins resulted in an increase in thiol and ester compounds post fermentation and these compounds are known to cause tropical fruit aroma in wines³. This work aimed to scale up these fermentations/operations to determine if the desired aromas could still be achieved and if there is a perceivable difference in tropical fruit aromas, liking, and emotional response in the wines at the consumer level.

CHANGES IN CU FRACTIONS AND RIBOFLAVIN IN WHITE WINES DURING SHORT-TERM LIGHT EXPOSURE: IMPACTS OF OXYGEN AND BOTTLE COLOUR

Copper in white wine can be associated with Cu(II) organic acids (Cu fraction I), Cu(I) thiol species (Cu fraction II), and Cu sulfides (Cu fraction III). The first two fractions are associated with the repression of reductive aromas in white wine, but these fractions gradually decrease in concentration during the normal bottle aging of wine. Although exposure of white wine to fluorescent light is known to induce the accumulation of volatile sulfur compounds, causing light-struck aroma, the influence on the loss of protective Cu fractions is uncertain. Riboflavin is known to be a critical initiator of photochemical reac-tions in wine, but the rate of its decay under short-term light exposure in different coloured bottles and for wine of different oxygen concentrations is not well understood.

EFFECTS OF BIODYNAMIC VINEYARD MANAGEMENT ON GRAPE RIPENING MECHANISMS

Biodynamic agriculture, founded in 1924 by Rudolph Steiner, is a form of organic agriculture. Through a holistic approach, biodynamic agriculture seeks to preserve the diversity of agriculture and the existing interactions between the mineral world and the different components of the organic world. Biodynamic grape production involves the use of composts, herbal teas and mineral preparations such as 500, 501 and CBMT.
Several scientific studies have provided evidence on the effects of biodynamic farming on the soil, the plant and the wine. Numerous empirical opinions of wine growers support the existence of differences brought by such a management.

WINE AS AN EMOTIONAL AND AESTHETIC OBJECT: IMPACT OF EXPERTISE

Wine tasting has been shown to provide emotions to tasters (Coste et al. 2018). How will expertise impact this emotional response? Burnham and Skilleås (2012) reported that the cultural, experiential, and aesthetic competencies characterize an expert in wine compared to a novice. Although there is no consensual definition of an aesthetic experience, Burnham and Skilleås (2012) reported that aesthetic appreciation is “disinterested, normative for others and communicable” in comparison to sensory pleasure.