Using a targeted metabolomic approach with UHPLC-MS/MS, we investigated the impact of native non-Saccharomyces yeasts on the lipid profile of Maraština wine produced through monoculture and sequential fermentations. Certain components exhibited opposite trends (increase or decrease) in sequential fermentation compared to monoculture and the initial must. Metschnikowia chrysoperlae and Metschnikowia pulcherrima produced more total free fatty acids and their esters in monoculture, while Metschnikowia sinensis/shanxiensis generated more free fatty acid esters in sequential fermentation with S. cerevisiae. The Hanseniaspora genus was the least affected by inoculation treatments, with most lipid compounds following the same trend. Exceptions included oleanolic and stearic acid for H. uvarum, and palmitoleic acid for H. guilliermondii. Hierarchical cluster analysis grouped native yeasts based on their influence on the synthesis or degradation of lipid compounds. The most significant impact observed in this study was on the biosynthesis of unsaturated fatty acids.

More details can be found at the following link: https://www.mdpi.com/2304-8158/14/2/269

On November 20, 2024, the final workshop of the research project “Impact of native non-Saccharomyces wine yeast on wine aromas” was held at the Institute for Adriatic Crops and Karst Reclamation. The results of the project, funded by the Croatian Science Foundation, were presented to interested participiants.

The project results were presented by:

• Dr. Irena Budić-Leto, project leader, on the topic:
  “Presentation of Research Project Results IP-2020-02-1872: The Influence of Indigenous Non-Saccharomyces Yeasts on Wine Aroma – WINE AROMAS”
• Ana Boban, mag.chem., PhD student, on the topic:
  “The Potential of Indigenous Non-Saccharomyces Yeasts to Enhance the Aroma of Maraština Wine”

With this workshop, we have achieved all the objectives of the research project “Impact of native non-Saccharomyces wine yeast on wine aromas” and successfully brought the project to its conclusion. 🎉

We presented part of the results of our research project at the scientific and professional conference on viticulture and winemaking, organized by the Faculty of Agriculture, University of Zagreb held during the 34^th International Meeting of Winegrowers and Winemakers – Sabatina 2024.

Sabatina took place in Mali Lošinj from November 14–17, 2024, organized by the Cooperative Union of Dalmatia and the Croatian Association of Wine Cities. The event brought together numerous participants, including representatives from the wine sector.

A lecture titled “The influence of indigenous non-Saccharomyces yeasts on the aromas of the Maraština wine” was presented by PhD student Ana Boban.

At the Biotechnical Faculty of the University of Ljubljana, Department of Biology, the final conference and Management Committee meeting of the COST Action CA 19116 PLANTMETALS was held from September 17 to 20, 2024. Dr. Irena Budić-Leto participated as a member of the Action’s Management Committee. At the gathering, we presented preliminary research results related to the metabolism of certain non-Saccharomyces yeast isolates and the concentration of metal ions and antioxidant activity in the wine of the Maraština grape variety.

Book of abstracts is available on the link: https://plantmetals.eu/PLANTMETALS2024_Book-of-Abstracts_25092024_print_final.pdf

This study examined the impact of indigenous non-Saccharomyces yeasts on wine aroma through monoculture and sequential fermentations with Saccharomyces cerevisiae. The primary metabolites and volatile profiles of Maraština wine were modified solely by the tested yeasts, as the research was conducted on sterilized must of the Maraština variety.

This is the first comprehensive study on the yeast strains Metschnikowia chrysoperlae, M. sinensis/shanxiensis, Hypopichia pseudoburtonii, and Starmerella apicola in wine technology research. In monoculture, fermentations with the M. pulcherrima isolate resulted in the lowest ethanol concentration and higher total terpene concentrations. Pichia kluyveri produced a high level of thiols and esters, while Hanseniaspora guilliermondii increased the total concentration of C13-norisoprenoids.

Seven sequential fermentations revealed interactions between indigenous non-Saccharomyces yeasts and commercial S. cerevisiae yeast. P. kluyveri – S. cerevisiae fermentations had the most distinctive volatile profiles compared to controls, especially in C13-norisoprenoid and ester concentrations. M. pulcherrima in sequential fermentation reduced the production of volatile phenols. The isolates did not affect wine color and produced lower polyphenol concentrations than S. cerevisiae. These results highlight different volatile profiles under the same winemaking conditions, emphasizing the biochemical role of each isolate in fermentation. This study represents a first step in understanding the positive roles of non-Saccharomyces yeasts in winemaking.

More details can be found at the following link:  https://www.sciencedirect.com/science/article/pii/S2772502224001641?via%3Dihub

We’re sharing with you the atmosphere from this year’s Researchers’ Night.

The event took place on September 27, 2024, as part of the Reconnect Science with the Blue Society 2.0 project, aimed at popularizing science.

See you next year!

Photo: Cropix and Wine Aromas

https://www.facebook.com/profile.php?id=61552472441834

A targeted metabolomic UHPLC-MS/MS approach was used to investigate the influence of H. uvarum, H. guilliermondii, L. thermotolerans, M. pulcherrima, and P. kluyveri isolates, as well as two yeast species not previously studied in wine-M. chrysoperlae and M. sinensis/shanxiensis-on the metabolism of aromatic amino acids during monoculture and sequential fermentations with S. cerevisiae. The results were compared with fermentations using commercially available strains of M. pulcherrima, L. thermotolerans, and S. cerevisiae.

The results demonstrate the impact of individual yeast strains in different fermentations. These findings will enhance the understanding of tryptophan, phenylalanine, and tyrosine metabolism, through which indigenous non-Saccharomyces yeast contribute to the aroma of wine.

More details can be found at the following link: https://www.mdpi.com/2304-8158/13/18/2939.

In the period from July 7 to July 11, 2024, the international conference Grapevine Physiology and Biotechnology – OpenGPB 2024 was held in Logrono, La Rioja, Spain. At the conference, we presented the latest research related to the metabolism of non-Saccharomyces isolates under the title:

“Autochthonous non-Saccharomyces extra-cellular metabolism of tryptophan, tyrosine, and phenylalanine,” authored by Ana Boban, Urska Vrhovsek, Andrea Anesi, Vesna Milanović, and Irena Budić-Leto.

Our poster, which showcased the results on aromatic amino acids and their derivatives in samples of must and experimental wine of the Maraština variety, was awarded the best poster presentation at OpenGPB 2024. The indigenous yeasts isolated and identified in this project exhibit diverse metabolism that can contribute to the formation of the secondary aroma of wine. Particularly notable are the species Metschnikowia sinensis/shanxiensis and Hanseniaspora guilliermondii.

We participated in the 5th European Horticulture Congress and the symposium Viticulture & Winemaking between Tradition & Innovation, held in Bucharest from May 12th to 16th, 2024, under the support of the International Society for Horticultural Science (ISHS).

PhD student Ana Boban had a short oral presentation titled “Impact of Autochthonous Non-Saccharomyces Yeasts on Wine Aroma Complexity”, co-authored by Ana Boban, Urska Vrhovsek, Silvia Carlin, Vesna Milanović, Jasenka Gajdoš Kljusurić, and Irena Budić-Leto.

The presentation showcased the initial results of the aromatic profile of Maraština wine, produced using different autochthonous non-Saccharomyces yeasts in sequential fermentation with Saccharomyces yeast.

The results indicate the positive influence of certain genera and strains of yeasts on increasing the concentration of volatile metabolites in the wine’s aroma.

The paper explores the impact of autochthonous microbiota on the phenolic composition of Maraština wine, as discussed in the journal Food Research International (Q1, IF=8.1). Employing a metataxonomic approach, we investigated the microbiota during spontaneous alcoholic fermentation, identifying and molecularly characterizing 95 distinct taxa at the species or genus level. Additionally, we established and validated an HPLC-UV/VIS method for identifying and quantifying 21 phenolic compounds. Through in-depth bioinformatics analysis, correlations with specific phenolic compounds in the wine were founded.

More details can be found at the following link: https://doi.org/10.1016/j.foodres.2024.114072