1. Lactic acid bacteria and Brettanomyces bruxellensis in Teran wine : impact on biogenic amines and volatile phenolsTatjana Radovanović Vukajlović, Shanique Walker, Julija Šupljika, Mitja Martelanc, Jan Reščič, Melita Sternad Lemut, Branka Mozetič Vodopivec, Dejan Bavčar, Klemen Lisjak, Lorena Butinar, 2025, objavljeni povzetek znanstvenega prispevka na konferenci Opis: Yeasts and lactic acid bacteria (LAB) are the main microorganisms involved in wine production, responsible for alcoholic fermentation and malolactic fermentation (MLF), respectively. During MLF, LAB convert L-malic acid into L-lactic acid, which primarily leads to biological deacidification but also results in changes to the wine’s aroma and microbiological stability. While LAB generally improve wine quality, certain strains can cause spoilage and are linked to the production of biogenic amines (BAs)—nitrogenous compounds such as histamine, tyramine, and putrescine. At elevated levels, BAs may pose health risks, especially for sensitive individuals, potentially causing headaches, hypertension, and digestive issues. Likewise, the yeast Dekkera/ Brettanomyces bruxellensis is considered a spoilage organism due to its ability to produce volatile phenolic compounds (e.g., 4-ethylguaiacol and 4-ethylphenol), which impart off-flavors resembling bandages, sweat, and smoke. As part of the AGROTUR+ project, we monitored LAB and B. bruxellensis populations, as well as BA and volatile phenol content, during MLF in Teran - a protected wine made from Refošk grapes in the Karst wine-producing region. The goal was to assess the presence of spoilage-related compounds and support improvements in microbiological quality of this traditional wine. A total of 26 Teran wine samples from the 2024 vintage were analyzed. Volatile phenols were analyzed using HS-SPME-GC-MS, and BAs were determined via HPLC–UV following sample derivatization. Basic quality physicochemical parameters were determined using standard methods. LAB and B. bruxellensis populations were estimated through conventional microbiological techniques and flow cytometry. Regarding BA content, histamine was the most abundant (average 21.9 mg/L), followed by putrescine (3.7 mg/L) and cadaverine (1.6 mg/L). No correlation was observed between total LAB counts and BA levels, indicating the need for further analysis of LAB strain composition. For volatile phenols, 4-ethylphenol was found at concentrations below its sensory threshold (600 µg/L), while 4-ethylguaiacol exceeded its threshold (110 µg/L) in three samples. In these, B. bruxellensis was detected using the CyFlow™ BrettCount flow cytometry kit (Sysmex Partec), though no colonies were observed on selective Dekkera/Brettanomyces differential medium (DBDM). Flow cytometry proved to be a rapid and specific method for detecting spoilage yeasts like B. bruxellensis, with strong potential for early intervention and spoilage prevention in winemaking.
Ključne besede: lactic acid bacteria, biogenic amines, Teran
Objavljeno v RUNG: 17.06.2025; Ogledov: 58; Prenosov: 0
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2. Microbiological screening of dried fruits and table grape present on Slovenian marketTatjana Radovanović Vukajlović, Melitta Buzás, Anej Colja, Anuša Skušek, Katarina Mukhina, Laura Smolnikar Štrukelj, Valentina Ratoša, Sara Gregorc, Branka Mozetič Vodopivec, Lorena Butinar, 2025, objavljeni povzetek znanstvenega prispevka na konferenci Opis: Dried fruits are a popular snack due to their high fiber content, but their production may pose microbiological risks, due to the nature of the processing methods, which can allow various microorganisms and their metabolic byproducts to persist. Among these byproducts are mycotoxins—such as ochratoxin A, patulin, and griseofulvin—which are of particular concern due to their potentially harmful effects on human health (Shahidi (2013)). In this study, samples from raisins, dried apricots, and table grapes available on the Slovenian market were analyzed to assess microbial contamination and potential mycotoxin production. Dried fruits and table grape samples were inoculated on MEA, WL, and PDA media and incubated to isolate yeasts and moulds. Morphological identification was performed using CREA and CYA media. For mycotoxin screening, selected mould cultures were extracted and analyzed using Thin Layer Chromatography (TLC), with standards for ochratoxin A, patulin, and griseofulvin. TLC plates were examined under UV light at 254 nm and 365 nm wavelength. DNA from isolates was also extracted and sent for sequencing to confirm species identification. The results showed that Aspergillus spp. were the predominant moulds in raisin samples, while Penicillium spp. were isolated from table grapes and various yeast strains from dried apricots. TLC analysis suggested the presence of griseofulvin in Aspergillus isolates, and possible traces of patulin and ochratoxin A in Penicillium samples. These findings are consistent with literature data ((Narayana (2021), Tournas et al. (2015)) on typical contaminants of dried fruits. Future studies using quantitative methods such as HPLC are needed to confirm and measure mycotoxin concentrations.
Ključne besede: mycotoxins, dried fruits, Slovenian market
Objavljeno v RUNG: 17.06.2025; Ogledov: 50; Prenosov: 0
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3. Exploring innovative approaches in flavored ciders : physicochemical and antioxidative properties of cornelian cherry – apple ciderErika Jež, Marianna Mazur, Tatjana Radovanović Vukajlović, Mitja Martelanc, Bartłomiej Menażyk, Maja Pečarič, Jelena Topić, Melita Sternad Lemut, Guillaume Antalick, Branka Mozetič Vodopivec, Lorena Butinar, 2024, objavljeni povzetek znanstvenega prispevka na konferenci Ključne besede: Cornelian cherry, apple cider, antioxidative properties
Objavljeno v RUNG: 27.11.2024; Ogledov: 1635; Prenosov: 1
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4. Vpliv uporabe različnih hrastovih trsk na aromatične značilnosti vina Rebula : diplomski seminarUroš Kurent, Lorena Butinar, 2024, raz. nal. na višji ali visoki šoli Opis: 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.
Ključne besede: Rebula, hrastovi sodi, hrastovi nadomestki, celokupni vtis vina
Objavljeno v RUNG: 23.10.2024; Ogledov: 1601; Prenosov: 0
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5. The effect of prolonged maceration with spontaneous fermentation on chemical and sensorial characteristics of white wineTara Seničić, 2024, raz. nal. na višji ali visoki šoli Opis: 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.
Ključne besede: white wine, prolonged maceration, spontaneous fermentation, sensorial characteristics
Objavljeno v RUNG: 19.08.2024; Ogledov: 1893; Prenosov: 3
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6. Foods2012 Ključne besede: food sciences and technology, food chemistry and physical properties, food engineering and production, food security and safety, food toxicology, sensory and food quality, food analysis, functional foods, food and health, food psychology, food and environment
Objavljeno v RUNG: 10.05.2024; Ogledov: 2295; Prenosov: 4
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7. Aromatic characterization of Graševina wines from Slavonia and Podunavlje sub-regionsMitja Martelanc, Guillaume Antalick, Tatjana Radovanović Vukajlović, Branka Mozetič Vodopivec, Melita Sternad Lemut, Ahmad Hosseini, Valentina Obradović, Josip Mesić, Lorena Butinar, 2024, izvirni znanstveni članek Opis: 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.
Ključne besede: Graševina–Welschriesling, aromatic profiling, HS-SPME-GCMS, terpenes
Objavljeno v RUNG: 08.04.2024; Ogledov: 2951; Prenosov: 20
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8. Chemical composition of apple cider : a comparative study of Norwegian and French cidersIngunn Ovsthus, Mitja Martelanc, Tatjana Radovanović Vukajlović, Marko Lesica, Lorena Butinar, Branka Mozetič Vodopivec, Guillaume Antalick, 2024, objavljeni znanstveni prispevek na konferenci Opis: Norwegian apple ciders have recently gained attention at the levels of international competitiveness. Accordingly, a comparative study on the chemical composition of selected Norwegian and French apple ciders was conducted to gain knowledge on what ubiquitous chemical parameters make the Norwegian ciders different from ciders from well-established producing regions. A total of 43 ciders, 24 Norwegian and 19 French, in the category of acidic dominant ciders, were included in the study. Ethanol, individual sugars and organic acids, pH, total phenols, aroma compounds including esters, C6-alcohols, volatile phenols and terpenoids, were analysed. Norwegian ciders showed higher contents in ethanol, malic and citric acids, whereas total phenols, pH, glucose, and fructose were higher in French counterparts. Regarding the aromatic profile, no significant differences were observed for C6-alcohols. In contrast, differences were more expressed in the case of esters and volatile phenols. Norwegian ciders were characterised by higher average concentration for all the groups of esters, with the most important differences measured for higher alcohol acetates. Norwegian ciders also displayed higher contents of 4-vinylphenol and 4-vinylguaiacol while French ciders contained substantially higher levels of 4-ethylphenol and 4-ethylguaiacol. These results are in mutual correlation with the empirical observation reporting Norwegian apple ciders as more acidic, alcoholic and with lighter body but fruitier profile. Whereas French ciders are often perceived with more structure and animalistic profile.
Ključne besede: alcohol, acidity, total phenols, aroma-compounds, apple cider
Objavljeno v RUNG: 25.03.2024; Ogledov: 3556; Prenosov: 8
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10. Functional characterization of Saccharomyces yeasts from cider produced in HardangerUrban Česnik, Mitja Martelanc, Ingunn Ovsthus, Tatjana Radovanović Vukajlović, Ahmad Hosseini, Branka Mozetič Vodopivec, Lorena Butinar, 2023, izvirni znanstveni članek Ključne besede: Saccharomyces, Hardanger, characterization, fermentation, cider, non-volatile compounds, volatile organic compounds, partial least squares regression
Objavljeno v RUNG: 18.09.2023; Ogledov: 2704; Prenosov: 10
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