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High doses of polypropylene and polyvinyl chloride microplastics affect the microbial community and nutrient status of vineyard soils
Erika Jež, Elisa Pellegrini, Melita Sternad Lemut, Maria De Nobili, Marco Contin, 2025, original scientific article

Abstract: Abstract The escalating use of plastic materials in viticulture causes release of microplastics (MPs) into vineyard soils. This study examines the impact on soil health of polypropylene (PP) raffia and polyvinyl chloride (PVC) tube strings, commonly mulched into the topsoil after use. A 120-d incubation experiment was conducted with soils exposed to high doses (10 g/kg) of microplastics (MPs) from standard, new and used strings. The study investigated alterations in the microbial community, bioavailability of macronutrients (NH4+ and NO3−, P, K, Ca, Mg), and bioavailability of micronutrients (Cu, Zn, Fe, Mg). The presence of MPs significantly stressed the soil microbial community, reducing microbial biomass by 30% after 30 d, with the exception of PVC in acid soil, which caused an unexpected increase of about 60%. The metabolic quotient (qCO2) doubled in MP-polluted soils, with PVC exerting a more pronounced effect than PP. Basal respiration increased by 25% relative to the acid control soil. PVC MPs raised soil pH from 6.2 to 7.2 and firmly reduced the bioavailability of micronutrients, particularly in acidic soils, and led to a 98% reduction in nitrate (NO3−). The availability of NH4+, P, K, Mg decreased by 10% and Cu, Fe, Mn, Zn by 30%. However, Ca availability increased by 30%, despite shifting from the acid-soluble fraction to soil organic matter and crystalline minerals. Calcareous soil was generally more resilient to changes than the acid soil. These findings underscore the urgent need to investigate the long-term effects of MPs from viticulture on soil properties and health.
Keywords: microplastics, soil, nutrient bioavailability, microbial community, viticulture
Published in RUNG: 22.11.2024; Views: 192; Downloads: 4
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3.
Enography of newly emerging wine-producing countries - Japan, China, India : graduation seminar 2023/24
M. Hovland, 2024, research project (high school)

Published in RUNG: 12.11.2024; Views: 186; Downloads: 0
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Vpliv uporabe različnih hrastovih trsk na aromatične značilnosti vina Rebula : diplomski seminar
Uroš Kurent, Lorena Butinar, 2024, research project (high school)

Abstract: V grozdju sorte 'Rebula' (Vitis vinifera L.) nekateri vinarji odkrivajo vedno večji potencial, vendar so poleg osnovne surovine (grozdja) za končno kakovost pomembni tudi primerno izbrani in izpeljani postopki vinifikacije ter zorenja vina. Z različnimi tehnološkimi pristopi pred in med alkoholno fermentacijo lahko bistveno vplivamo na končno aromatično kakovost vina. Na aromatični potencial vina pa lahko vplivamo tudi z odločitvami po alkoholni fermentaciji in v času zorenja vina, tudi z zorenjem vina v hrastovih sodih ali ob uporabi t.i. hrastovih nadomestkov. V diplomskem delu smo pridelali eksperimentalna vina rebula po štirih različnih vinifikacijskih postopkih ter jim nato dodali trske bodisi ameriškega ali francoskega hrasta, z različnimi stopnjami žganja lesa. Tako pridelana mlada vina smo senzorično ovrednotili in zaznali določene razlike v percepciji vin glede na različne dodatke hrastovih trsk. Vina pridelana z dodatkom hrastovih trsk so degustatorji senzorično ocenili bolje kot kontrolna vina. Iz tega lahko sklepamo, da je dodatek hrastovih trsk izboljšal celokupni vtis vina. Bistvenih razlik med vini glede na poreklo hrastovih trsk (ameriški srednje žgan in francoski srednje žgan) degustatorji niso zaznali.
Keywords: Rebula, hrastovi sodi, hrastovi nadomestki, celokupni vtis vina
Published in RUNG: 23.10.2024; Views: 304; Downloads: 0
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6.
The effect of prolonged maceration with spontaneous fermentation on chemical and sensorial characteristics of white wine
Tara Seničić, 2024, research project (high school)

Abstract: The use of prolonged maceration and spontaneous fermentation in white wine production is gaining renewed interest among winemakers, considering rising consumer interest in sustainable and traditional winemaking. This seminar aimed to assess how these approaches influence the sensory and chemical profiles of white wines based on available literature. Additionally, chemical analyses were conducted on three ‘Ribolla gialla’ variety wines from Vipava valley, which were produced using the aforementioned technology. The analyses indicated the presence of a wide range of aromatic compounds including esters and C-6 alcohols found in ‘Ribolla gialla’ wine samples. Spoilage indicators such as 4-ethylguaiacol and 4-ethylphenol were detected in some ‘Ribolla gialla’ samples, highlighting the risks of spontaneous fermentation. Assessing the reviewed literature data, prolonged maceration can enhance the aromatic complexity of white wines as related to the higher content of monoterpenes and phenolic compounds. This study supports the potential of these traditional methods to create unique and complex wines, but further research is needed to optimize these technological approaches and ensure consistent quality.
Keywords: white wine, prolonged maceration, spontaneous fermentation, sensorial characteristics
Published in RUNG: 19.08.2024; Views: 685; Downloads: 1
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7.
Aromatic characterization of Graševina wines from Slavonia and Podunavlje sub-regions
Mitja Martelanc, Guillaume Antalick, Tatjana Radovanović Vukajlović, Branka Mozetič Vodopivec, Melita Sternad Lemut, Ahmad Hosseini, Valentina Obradović, Josip Mesić, Lorena Butinar, 2024, original scientific article

Abstract: This study investigated the chemical aromatic profiles of 60 volatile organic compounds (VOCs), including 21 terpenes, 6 norisoprenoids, 6 volatile phenols, 4 C-6 alcohols, and 23 esters, in Graševina wines originating from Slavonia and Podunavlje sub-regions (Croatia). Headspace solid-phase microextraction gas chromatography coupled with mass spectrometric detection (HS-SPME-GCMS) was used to assess 60 VOCs, and a novel HS-SPME-GCMS method for the determination of terpenes and norisoprenoids was developed and validated. Statistical analysis also found no significant differences between VOCs present in Graševina wines and others wines (Chardonnay and Pinot gris); nonetheless, comparison of VOC fingerprints between different wines from the same producer showed that four terpenes (α-terpinene, γ-terpinene, 1,4-cineol, and 4-terpineol) were present in higher amounts in Graševina wines when compared to other wines. By exclusively examining VOCs within Graševina wines through the utilization of a heatmap and hierarchical clustering, a distinct visualization of samples and VOCs emerged, highlighting the vintage effect. Simultaneously, a partial least squares discriminant analysis model was developed with a confidence interval of 95%, demonstrating a noticeable distinction between samples originating from the western and eastern regions. Furthermore, by employing the heatmap using only VOCs from the terpene and norisoprenoidic groups, a clear separation of samples into two groups was observed based on geographical origin; namely, higher concentrations of norisoprenoids and terpenes were observed in the Slavonia sub-region. These results suggest that terpenes and norisoprenoids to a lower extent may be valuable aromatic markers for the regional typicality of Graševina wines.
Keywords: Graševina–Welschriesling, aromatic profiling, HS-SPME-GCMS, terpenes
Published in RUNG: 08.04.2024; Views: 1624; Downloads: 16
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8.
Uporaba lesa v vinarstvu : diplomski seminar
Matija Gregorič, 2023, research project (high school)

Keywords: les, sodi, zorenje vina, vpliv lesa, senzorične lastnosti vina
Published in RUNG: 17.11.2023; Views: 1597; Downloads: 0
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9.
Upočasnjena ali ustavljena alkoholna fermentacija : možni vzroki in rešitve
Maruša Mulej, 2023, research project (high school)

Keywords: alkoholna fermentacija, upočasnjena fermentacija, ustavljena fermentacija
Published in RUNG: 17.11.2023; Views: 1614; Downloads: 0
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10.
SCREENING AND EVALUATION OF ENZYMATIC ACTIVITIES OF WINE RELATED YEAST SPECIES
Adesida Rowland, Melita Sternad Lemut, Lorena Butinar, 2020, published scientific conference contribution abstract

Abstract: A number of indigenous yeast strains isolated from vineyard / cellar-associated samples and non-vineyard sites, from forests with oak trees (a known habitat where Saccharomyces species resides) from existing in-house yeast collection and from ZIM culture collections (Slovenia) were screened for enzymatic activities with enological importance. The yeasts were screened for glycosidase enzymes connected to terpene aroma release, the β-lyase activity responsible for the volatile thiol release, and sulfite reductase activity involved in off-flavours. Yeast strains that showed positive results for qualitative and quick detection of glucoside hydrolase activity on plates were selected for further studies. The glucoside hydrolase activity of 20 selected strains belonging to 15 different species was quantitatively characterized by determinations of the activity on pNPG. All strains demonstrated hydrolase activity, especially strain H. uvarum 116 which showed the highest value of specific activity 6.32 mU/mg for cell-associated activity and T. delbrueckii Sut 94 with highest value of specific activity 1.36 mU/mg for extracellular activity. Increased growth of tested yeast on medium containing substrate S-methyl-L-cysteine indicated β-lyase activity, and by this approach a moderate activity was recorded throughout our tested strains with immense intraspecific inconsistency. Noticeable H2S production was observed in P. manshurica strain whereas, H. uvarum, L. thermotolerance, S. bayanus and S. cerevisiae demonstrated weak/slight H2S-producer strains in our study. Therefore, our screening indicates the importance of strain selection for enological application due to intraspecies differences, as well as the introduction of non-Saccharomyces yeast starters with interesting potential to enhance wine aroma.
Keywords: wine yeasts, non-Saccharomyces, enzymatic activities
Published in RUNG: 08.05.2023; Views: 1748; Downloads: 0
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