This study investigates the colour and standard chemical composition of must and wines produced from the grapes from Vitis vinifera L., ‘Maraština’, harvested from 10 vineyards located in two different viticultural subregions of the Adriatic region of Croatia: Northern Dalmatia and Central and Southern Dalmatia. The aim was to explore the use of NIR spectroscopy combined with chemometrics to determine the characteristics of Maraština wines and to develop calibration models relating NIR spectra and physicochemical/colour data. Differences in the colour parameters (L*, a*, hue) of wines related to the subregions were confirmed. Colour difference (ΔE) of must vs. wine significantly differed for the samples from the Maraština grapes grown in both subregions. Principal component regression was used to construct the calibration models based on NIR spectra and standard physicochemical and colour data showing high prediction ability of the 13 studied parameters of must and/or wine (average R² of 0.98 and RPD value of 6.8). Principal component analysis revealed qualitative differences of must and wines produced from the same grape variety but grown in different subregions.

This study investigated the detailed volatile aroma profile of young white wines of Maraština, Vitis Vinifera L., produced by spontaneous fermentation. The wines were produced from 10 vineyards located in two Dalmatian subregions (Northern Dalmatia and Central and Southern Dalmatia). Volatile compounds from the wine samples were isolated by solid-phase extraction (SPE) and analyzed by an untargeted approach using two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC/TOF-MS) and a targeted approach by gas chromatography–tandem mass spectrometry (GC-MS/MS). A comprehensive two-dimensional GC×GC analysis detailed the total volatile metabolites in the wines due to its excellent separation ability. More than 900 compounds were detected after untargeted profiling; 188 of them were identified or tentatively identified. A total of 56 volatile compounds were identified and quantified using GC-MS/MS analysis. The predominant classes in Maraština wines were acids, esters, and alcohols. The key odorants with odor activity values higher than one were β-damascenone, ethyl caprylate, ethyl isovalerate, ethyl 2-methylbutyrate, ethyl caproate, isopentyl acetate, ethyl butyrate, and phenylacetaldehyde. The metabolomics approach can provide a large amount of information and can help to anticipate variation in wines or change winemaking procedures.

This study aimed to provide novel information on the impact of indigenous non-Saccharomyces yeasts, including Metschnikowia chrysoperlae, Metschnikowia sinensis/shanxiensis, Metschnikowia pulcherrima, Lachancea thermotolerans, Hanseniaspora uvarum, Hanseniaspora guilliermondii, and Pichia kluyveri, on metabolites related to the metabolism of tryptophan, phenylalanine, and tyrosine. The experiment included two fermentation practices: monoculture and sequential fermentation with commercial Saccharomyces cerevisiae, using sterile Maraština grape juice. A targeted approach through ultrahigh-resolution liquid chromatography associated with mass spectrometry was used to quantify 38 metabolites. All the indigenous yeasts demonstrated better consumption of tryptophan in monoculture than in interaction with S. cerevisiae. M. sinensis/shanxiensis was the only producer of indole-3-carboxylic acid, while its ethyl ester was detected in monoculture fermentation with H. guilliermondii. H. guilliermondii consumed the most phenylalanine among the other isolates. 5-hydroxy-L-tryptophan was detected in fermentations with M. pulcherrima and M. sinensis/shanxiensis. M. pulcherrima significantly increased tryptophol content and utilised tyrosine in monoculture fermentations. Sequential fermentation with M. sinensis/shanxiensis and S. cerevisiae produced higher amounts of N-acetyl derivatives of tryptophan and phenylalanine, while H. guilliermondii-S. cerevisiae fermentation resulted in wines with the highest concentrations of L-kynurenine and 3-hydroxyanthranilic acid. P. kluyveri produced the highest concentration of N-acetyl-L-tyrosine in monoculture fermentations. These findings highlight the different yeast metabolic pathways.

This research aimed to analyze the impact of two different non-Saccharomyces yeast species on the aromatic profile of red wines made from the cv. Babić (Vitis vinifera L.) red grape variety. The grapes were obtained from two positions in the Middle and South of Dalmatia. This study compared a control treatment with the Saccharomyces cerevisiae (Sc) strain as a type of sequential inoculation treatment with Lachancea thermotolerans (Lt x Sc) and Torulaspora delbrueckii (Td x Sc). The focus was on the basic wine parameters and volatile aromatic compound concentrations determined using the SPME-Arrow-GC/MS method. The results revealed significant differences in cis-linalool oxide, geraniol, neric acid, and nerol, which contribute to the sensory profile with floral and rose-like aromas; some ethyl esters, such as ethyl furoate, ethyl hexanoate, ethyl lactate, ethyl 2-hydroxy-3-methylbutanoate, ethyl 3-hydroxy butanoate, diethyl glutarate, and diethyl succinate, contribute to the aromatic profile with fruity, buttery, overripe, or aging aromas. A sensory evaluation of wines confirmed that Td x Sc treatments exhibited particularly positive aromatic properties together with a more intense fullness, harmony, aftertaste, and overall impression.

Lipids are a diverse group of organic compounds that serve essential roles due to their biological functions for all prokaryotic and eukaryotic organisms. Despite the fundamental role of lipid class in plants, there is still a relatively low level of knowledge regarding the composition of grape lipids. This research represents the first investigation into the lipids of the Croatian grape variety ‘Maraština’ (Vitis vinifera L.), employing a targeted approach and the UHPLC-MS/MS method to conduct a comprehensive analysis of the lipid profile of grape skins. The study investigated the profile of free fatty acids, glycerolipids, glycerophospholipids, triterpenoids, sphingolipids, and free fatty acid esters in eleven vineyards located along the cultivation area of ‘Maraština’ variety (Dalmatia, Croatia). Grape skins from vineyards that were exposed to more sunlight and higher daily temperature during the vegetation period mainly resulted in a richer profile of free fatty acids. Among lipids, ‘Maraština’ grape skins were characterized mainly by a triterpenoid compound; oleanolic acid (249.49 µg/g of FW), and free fatty acids, especially palmitic acid C16:0 (26.09 µg/g of FW), and lignoceric acid C24:0 (12.40 µg/g of FW). Hierarchical clustering analysis represented valuable insights into the diversity of lipids in ‘Maraština’ grape skin.

This study is the first to investigate the impact of indigenous non-Saccharomyces yeasts, including Hypopichia pseudoburtonii, Metschnikowia sinensis/shanxiensis, Metschnikowia chrysoperlae, Metschnikowia pulcherrima, Lachancea thermotolerans, Hanseniaspora uvarum, Hanseniaspora guilliermondii, Hanseniaspora pseudoguilliermondii, Pichia kluyveri, and Starmerella apicola on the lipid composition of sterile Maraština grape juice and wines using the UHPLC-MS/MS method. Yeasts were tested in monoculture and sequential fermentations alongside commercial Saccharomyces cerevisiae. Indigenous non-Saccharomyces yeasts showed the potential to improve fermentation performance and enable the development of new wine styles through the biosynthesis of an unsaturated fatty acid pathway, which was identified as the most significant pathway. In monoculture fermentations, L. thermotolerans, H. uvarum, H. guilliermondii, H. pseudoguilliermondii, and P. kluyveri significantly reduced lignoceric acid, potentially influencing wine aroma through the formation of esters and higher alcohols. Hyp. pseudoburtonii, M. chrysoperlae, M. pulcherrima, P. kluyveri, and S. apicola increased the demand for lipids, such as stearic acid, which may help preserve membrane permeability by integrating into the membrane in response to ethanol shock. The most significant impact on free fatty esters was observed in fermentations with H. pseudoguilliermondii. Furthermore, L. thermotolerans in sequential fermentations significantly reduced arachidic, stearic, and palmitic acid. P. kluyveri reduced the content of erucic and linoleic acid.