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Keywords: Cornelian cherry, apple cider, antioxidative properties
Published in RUNG: 27.11.2024; Views: 1064; Downloads: 1
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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: 1357; Downloads: 2
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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: 2392; Downloads: 16
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Keywords: soil, microplastic, viticulture
Published in RUNG: 10.11.2023; Views: 2509; Downloads: 0
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Abstract: The presence of bioactive compounds in food and beverages of plant origin is mainly connected with higher nutritional value and better sensory properties. However, some of them can pose a threat to food product quality and human health. For example, excess biogenic amines (BAs) intake can cause different allergenic responses in individuals who have such intolerances. BAs have been intensively studied in recent years, especially in fermented foods like wine, meat, fish, and cheese. Among fermented beverages is apple cider still rather unexplored from this perspective. Especially since no such data exist for the Norwegian cider. Norwegian cider is becoming more and more popular in Norway in recent years among producers and consumers. Hardanger cider from Western Norway is very different from French, English, or Spanish ciders in terms of sensory characteristics, apple cultivars, and in the fermentation process. In Hardanger, the traditional cider is still produced by spontaneous fermentation of apple juice with naturally occurring yeasts that originate from the fruit or processing equipment surfaces. Lactic acid bacteria are known to be associated with BA formation. However, several studies reported about the BA-producing yeasts in winemaking. Due to the important role of natural yeasts in the production of Hardanger cider, we focused on the ability of BA formation by native yeasts. Thus, in our study, we followed the amounts of BAs in the Hardanger ciders during the fermentation process and characterize isolated yeasts if they have the ability to produce BAs under cidermaking conditions by performing a micro-fermentation experiment. From must/cider samples, taken during the fermentation process at 13 producers in the Hardanger region, we isolated 530 yeast isolates. Based on the sequencing of the D1/D2 domain of the 26S rDNA we identified 25 different yeast species. As expected, yeast diversity was higher at the beginning compared to the middle fermentation stage, when mostly different non-Saccharomyces yeast species prevailed, while at the end of fermentation mainly Saccharomyces species with high ethanol tolerance were present. BAs were analyzed with the HPLC-UV method. In all apple juice/cider samples 4 different BAs (putrescine, cadaverine, histamine, and tyramine) were detected and quantified with external calibration. On average in all cider samples from the producers total BA (summation of all BAs) concentration reached 9,45 mg/L, however in one case even 25 mg/L. Tyramine was the most abundant BA in all fermentation stages. 40 isolated yeast strains were further tested for BA formation in a small-scale experiment by fermenting apple juice. Results show that non-Saccharomyces yeasts mainly form histamine (1,68 mg/L) and tyramine (1,30 mg/L), while Saccharomyces yeasts putrescine (0,48 mg/L) and tyramine (3,53 mg/L). As a general conclusion, the occurrence and distribution of BA concentrations in the small-scale fermentation were lower (2,96 mg/L and 4,01 mg/L) and less variable than in the real ciders (average in final ciders 9,45 mg/L) and with tyramine being the most abundant BA in all samples analyzed.
Keywords: cider, yeast, biogenic amines, Hardanger, biodiversity
Published in RUNG: 23.06.2023; Views: 2663; Downloads: 9
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