Complexity and dynamics of the winemaking bacterial communities in berries, musts, and wines from apulian grape cultivars through time and space

Currently, there is very little information available regarding the microbiome associated with the wine production chain. Here, we used an amplicon sequencing approach based on high-throughput sequencing (HTS) to obtain a comprehensive assessment of the bacterial community associated with the production of three Apulian red wines, from grape to final product. The relationships among grape variety, the microbial community, and fermentation was investigated. Moreover, the winery microbiota was evaluated compared to the autochthonous species in vineyards that persist until the end of the winemaking process. The analysis highlighted the remarkable dynamics within the microbial communities during fermentation. A common microbial core shared among the examined wine varieties was observed, and the unique taxonomic signature of each wine appellation was revealed. New species belonging to the genus Halomonas were also reported. This study demonstrates the potential of this metagenomic approach, supported by optimized protocols, for identifying the biodiversity of the wine supply chain. The developed experimental pipeline offers new prospects for other research fields in which a comprehensive view of microbial community complexity and dynamics is desirable.Peer ReviewedPostprint (published version

Traubenwachstum und biochemische Eigenschaften der Tafeltraubensorte ‘Trakya Ilkeren’ (V. vinifera L.) nach Vorernte-Behandlungen mit verschiedenen Konzentrationen von Wasserstoffperoxid und Phenylalanin

Uneven grape ripening, leading to decreases economic valued of grapes is one of the main problems faced by grape growers in early table grape growing. In recent years, there has been increasing concern about improving of fruit quality in fruit crops. Among the various quality improvement methods, different types of foliar compounds are used for this purpose and hydrogen peroxide (H2O2) and phenylalanine (Phe) can be given as examples to some of these chemicals. This research was carried out during the 2015 growing season by using early ripening table grape cv. Trakya Ilkeren. In the study, it was assessed that how different doses of hydrogen peroxide (0, 10, 20 and 40mM) and phenylalanine (0, 1, 2 and 4mM) affected physical and biochemical properties of cv. Trakya Ilkeren. In terms of physical properties, doses of hydrogen peroxide and phenylalanine had only significant effects on grape firmness and cluster length. The best results were obtained from 4mM Phe application (6.76N) in grape firmness and were obtained from applications of 10, 20 and 40mM H2O2 (23.66, 23.86 and 23.99cm) and applications of 1, 2, and 4mM Phe (23.95, 24.46 and 24.88cm) in cluster length. However, most of biochemical properties were considerably affected by doses of hydrogen peroxide and phenylalanine except for juice pH and p-value. It was recorded that the highest total phenolic compounds contents varied from 3571.28 (10mM H2O2) to 3871.22mg GAE kg(-1) fw (40mM H2O2) compared to 0mM application (2591.48mg GAE kg(-1) fw). In terms of total anthocyanin content, the highest mean was recorded for 4mM Phe application (330.56mg GAE kg(-1) fw) than 0mM application (168.79mg GAE kg(-1) fw). As aresult, 4mM Phe application particularly improved the most of biochemical properties in cv. Trakya Ilkeren

Phenolic composition of monovarietal red wines regarding volatile phenols and its precursors

The aim of this study was to characterise and compare wines from different grape varieties focusing on the volatile phenols and on the respective precursor compounds, both on the free form (p-coumaric, ferulic and caffeic acids) and as tartaric esters of hydroxycinnamic acids (caftaric, coutaric and fertaric acids). Fifty-eight commercial monovarietal red wines from eight selected grape varieties were used: Cabernet Sauvignon, Syrah, Aragonez, Castelão, Touriga Franca, Touriga Nacional, Trincadeira and Vinhão (Sousão). It was found that volatile phenol precursors exist mostly as esters of tartaric acid, with caftaric acid as the most abundant cinnamate (17–111 mg/L), followed by coutaric and fertaric acids. The predominant hydroxycinnamic acid was p-coumaric acid, the highest concentrations being found in Syrah and Touriga Franca (6–7 mg/L) and the lowest in Touriga Nacional and Trincadeira (2–3 mg/L). Touriga Nacional exhibits the highest difference between bound and free forms. Malvidin-3-O-(6-p-coumaroyl)-glucoside, a potential source of p-coumaric acid, was found in most of the wines with average values varying between 1 and 5 mg/L. Twenty-two percent of the wines analysed presented levels of volatile phenols above the perception threshold. Ethylphenols were the highest in Vinhão and Trincadeira, showing an average value well above the perception threshold. The concentrations found in Cabernet Sauvignon and Syrah wines were around ten times lower than those reported in previous works. The results show relevant differences among grape varieties but the availability of the precursors in meaningful amounts may not be the only factor explaining the formation of volatile phenols in wines.info:eu-repo/semantics/publishedVersio

HPLC-DAD-MS analysis of anthocyanins in rose wine made from cv. okuzgiozu grapes, and effect of maceration time on anthocyanin content

WOS: 000249232900010The anthocyanin composition of rose wine made from cv. Okuzgozu, a variety of grape native to Turkey, and the effect of maceration time (3, 6, 12, 18, or 24 k) on the anthocyanin content of the wine have been investigated. High-performance liquid chromatography with diode-array detection (HPLC-DAD) and mass spectrometry (MS) were used for anthocyanin analysis. Thirteen different anthocyanins, including live glucosides, five acetyl glucosides, and three cournaroyl glucosides were identified and quantified. It was found that an important ckaracteristic of Okuzgozu rose wine was the presence of a large amount of malvidin-3-glucoside and its acylated esters. The total antkocyanin content of the wine increased with increasing maceration time. On the basis of sensory analysis, the most preferred wine was that produced with 3-h maceration, because of its better color and general flavor attributes