Search Results (27)

Wine samples (72) of different types (white, rose and red), dry, originating from different regions of Greece (Northern Greece, Central Greece, Peloponnese, Aegean Islands, and Crete), were analyzed for Ochratoxin A (OTA) presence. Wine samples, originating from Greek (Assyrtiko and Xinomavro) and international (Syrah and Sauvignon blanc) noble grapevine varieties vintaged from 2020 to 2023, were analyzed using a modified QuEChERS extraction protocol followed by HPLC with a fluorescence detector to detect and quantify OTA. Moreover, conventional oenological parameters were measured according to OIV official methods, and climatic conditions of the regions of concern were retrieved. Interestingly, in general, OTA contaminated wines showed low concentrations (<2.0 μg/L). The highest concentrations of OTA were detected in Sauvignon blanc (7.5 μg/L) regarding the white wines and Xinomavro (2.07 μg/L) regarding the red ones. In addition, the highest OTA concentrations were recorded in wines produced in areas either with high mean annual temperatures, like Viotia (24.16 °C) for white and Larissa (23.9 °C) for red wines, or with high rainfall between May and September (Larissa 69.76 mm) for white wines. Consequently, it was observed that concentrations of OTA in wine are relatively higher in the warmer regions of Greece compared to the cooler areas. The effect of climate change on vines and mycotoxin presence in wine needs urgent consideration by well-constructed modelling studies and efficient interpretation of existing data. The evaluation of OTA presence in grape products originating from various cultivars and regions is imperative not only for providing crucial data to predict its fate under climate change, but also to ascertain the potential risk of human exposure to this chemical compound. Full article

This study examined the impact of five grapevine rootstocks (R110, 140Ru, 3309C, 41B, and FERCAL) on must composition, nitrogen status, and sensory attributes of Vitis vinifera L. cv. Assyrtiko wines. Vines were grown under uniform vineyard conditions, and microvinifications were conducted consistently across treatments. Rootstock genotype significantly influenced Baumé, density, titratable acidity, pH, and yeast-assimilable nitrogen (YAN). Musts from R110 contained the highest YAN (226.80 ± 0.99 mg/L) and intermediate Baumé (12.5°), whereas 140Ru exhibited the lowest YAN (132.60 ± 0.46 mg/L) and Baumé (11.7°). Wines from R110 contained the highest tannin concentration (0.375 g/L), while FERCAL produced the highest ethanol content (13.1% vol). Sensory evaluation revealed significant rootstock effects on color intensity, aroma intensity, aroma complexity, balance, and overall quality, with R110 and 3309C receiving the highest scores. The findings demonstrate that rootstock selection may affect the chemical and sensory profile of Assyrtiko wines, providing a practical tool for optimizing wine style and quality across diverse viticultural environments. Further research is needed to confirm these findings and explore extra parameters and novel rootstock–scion interactions. Full article

This study investigates the effects of rising temperatures on photosynthetic efficiency and stress tolerance in major Greek grapevine cultivars by using Sauvignon Blanc and Merlot as references. Muscat and Assyrtiko displayed the most heat-tolerant photosynthetic apparatus among the white cultivars, while Mavrodafni was the most heat-tolerant among the red ones, by effectively managing excess light energy. Sauvignon Blanc, although exhibiting heat susceptibility, maintained high photosystem II (PSII) functionality under heat stress by activating photoprotective mechanisms. Savvatiano and Agiorgitiko were more vulnerable to photo-oxidative stress above 35 °C, while Agiorgitiko maintained a functional photosynthetic apparatus, even at 40 °C, by shifting to a more photoprotective strategy. In contrast, Merlot, despite its resistance to photo-oxidative stress, lacked photoprotective investment, resulting in suppressed PSII under heat stress. Moschofilero was the most susceptible cultivar to photo-oxidative stress. Leaf morphological traits also contributed to heat stress tolerance, with smaller, thicker leaves facilitating thermoregulation. The present results provide important insights into specific responses to heat stress of major Greek grapevine cultivars. This knowledge may aid in selecting heat-tolerant genotypes and optimizing vineyard site selection, thereby enhancing the sustainability and climate resilience of viticulture. Full article

Vitis vinifera L. cultivar, “Assyrtiko”, is a famous grape variety native to Santorini island. Its wine production residues are rich in bioactive polyphenols, making them valuable for extraction and use in cosmetics. The aim of this work was the development and optimization of an extraction process from “Assyrtiko” Wine Production Residue (AWPR), using a Natural Deep Eutectic Solvent (NaDES) as the extraction medium. Four NaDESs were synthesized and screened for the extraction, and the extracts were evaluated for Total Phenolic Content (TPC) and Total Flavonoid Content (TFC). The NaDES comprising betaine and 1,3-propanediol was chosen for further analysis because of its effectiveness as an extraction solvent. The extraction process was optimized using a Box–Behnken experimental design. The NaDES %w/w content in the NaDES/water system was found to play the most statistically significant role in the quality of the extracts, assessed via TPC and TFC values. The quality of the extract obtained from the optimal conditions was practically stable with respect to TPC and TFC after long storage, suggesting that NaDESs have a potential “protective” effect for the extracted phytochemicals and give energy-efficient character to the process. This extract was also directly incorporated into a moisturizing cosmetic formulation, which remained homogeneous and stable after testing, demonstrating the extract’s potential for cosmetic applications. Full article

This study explores the chemical and sensory differentiation of Greek white wines produced from five indigenous grape varieties—Savvatiano, Vidiano, Moschofilero, Assyrtiko, and Malagouzia—across diverse terroirs in Greece. A targeted analytical approach was employed to quantify 12 key volatile aroma compounds derived primarily from amino acid metabolism and lipid degradation, using GC-MS and GC-FID. The selected volatiles, including isoamyl alcohol, phenylethyl alcohol, tyrosol, and hexanoic acid ethyl ester, were chosen for their sensory relevance and their biosynthetic linkage to nitrogenous precursors. Principal Component Analysis (PCA) of wines from the 2019 and 2020 vintages revealed clear varietal clustering, under standardized winemaking conditions. Malagouzia wines were characterized by rich and diverse volatile profiles, particularly long-chain fatty acids and esters, while Vidiano exhibited a consistently restrained aromatic expression. Sensory analysis using sorting and ultra-flash profiling confirmed the chemical clustering, with Moschofilero, Vidiano and Malagouzia wines forming distinct sensory groups. The findings demonstrate that key amino acid-derived volatiles can serve as biochemical markers of varietal typicity and support the use of volatile profiling as a tool for terroir-driven wine classification and quality assessment in Greek white wines. Full article

This study investigates the impact of climate change on key physiological parameters of Greek indigenous grapevine cultivars (Savvatiano, Muscat, Assyrtiko, Mavrodafni, Moschofilero, and Agiorgitiko), using Sauvignon blanc and Merlot as benchmarks. The aim was to identify genotypes with higher photosynthetic dynamics and water use efficiency (WUE) under heat stress and to examine the role of CO₂ enrichment in modulating these responses. Gas exchange measurements showed that short-term exposure to elevated CO₂ (e[CO₂]) (i.e., 700 ppm) enhanced photosynthesis by 37–64%, 77–89%, and 18–68% under control, moderate, and severe heat-stress regimes (23, 35, and 40 °C), respectively. CO₂ enrichment also improved WUE by 61–122%, 96–138%, and 11–63%, with the greatest benefits at 30–33 °C, depending on genotype. Cultivars with strong CO₂-saturated photosynthetic capacity and small stomata, such as Sauvignon blanc and Mavrodafni, showed greater photosynthetic stimulation and WUE improvement from CO₂ elevation. Stomatal traits influenced photosynthesis under ambient CO₂ (a[CO₂]) but not under e[CO₂]. Of the white varieties examined, Sauvignon blanc and Savvatiano showed the best performance under combined e[CO₂] and heat stress, while Assyrtiko and Muscat adapted better to high temperatures at a[CO₂]. Among red cultivars, Mavrodafni showed the highest photosynthetic efficiency at both CO₂ conditions, even under heat stress. The present findings indicate that grapevine varieties exhibit differential responses to elevated temperature and CO₂ levels. A comprehensive understanding of grapevine responses to stress conditions is therefore essential for the selection of cultivars with enhanced adaptation to climate change. Full article

(1) Background: High temperatures and water scarcity, intensified by climate change, present major challenges to Mediterranean viticulture. In this study morphological, anatomical, and physiological responses of leaves at two developmental stages of Vitis vinifera L. cv. Assyrtiko were examined. (2) Methods: Young expanding and fully expanded leaves of two-year-old grapevines grown in pots in a controlled growth chamber, grown in soil in an open-air vineyard, and an adjacent greenhouse on Aegina Island (Greece), were used. The plants were subjected to water deficit (WD), elevated temperature (ET), and combined water deficit and elevated temperature (WD_ET) conditions for four months, and compared with control plants (C). (3) Results: Stress conditions caused contrasting effects on specific leaf area (SLA), which declined in young expanding leaves, except for a significant increase under elevated temperatures, while it increased in fully expanded leaves exposed to stress treatments. Concerning the anatomical traits, the thickness of spongy and palisade parenchyma did not change in young expanding leaves exposed to the three stress treatments, but increased in fully expanded leaves exposed to WD_ET. Metabolic traits (phenolic compounds, soluble sugars, and starch content) further highlighted these differences. (4) Conclusions: The findings reveal distinct stress responses between young expanding and fully expanded leaves of the grapevine Assyrtiko, underscoring the influence of water deficit and elevated temperatures on leaf developmental stage. Full article

The aim of the present study was to assess the qualitative and quantitative characteristics of the grapes and berries of seven different biotypes (A1–A7) of grapevine cultivar Assyrtiko, cultivated in Santorini. All biotypes of grapevine cultivar Assyrtiko are cultivated in the same soil and climatic conditions in the area of Akrotiri. Grapes from the different biotypes were collected during technological maturity. In the must of all samples, the following measurements were carried out: total soluble solids concentration, active acidity (pH), and total titratable acidity. Also, mechanical analyses of the grapes and berries of all the biotypes under study were performed. Moreover, using a spectrophotometer, the content of grape’s skin in total phenolics, condensed tannins, total ortho-diphenols, total flavonoids, total flavanols, total flavonols and flavones, and their antioxidant capacity with the use of FRAP and DPPH methods were quantified, while high-performance liquid chromatography (HPLC) identified the most important individual acids and individual sugars. The same measurements were also carried out for the grape seeds. The results of the present study revealed the effect of the biotype both in the qualitative and the quantitative characteristics of grape cultivar Assyrtiko, with statistically significant differences being observed among the different biotypes. Full article

The objective of this work was to investigate the effect of location on the composition and quality of wines from the viticultural zone PGI Drama. Grapes from two white (Sauvignon blanc, Assyrtiko) and three red varieties (Merlot, Cabernet Sauvignon, Agiorgitiko) were collected from nine locations within the zone during 2022. The vineyards span distances ranging from several hundred meters to 100 km, and their altitudes vary from 90 to nearly 820 m. Vinification was performed following the same protocol according to the type of wine. Wines were analyzed for quality parameters such as pH, total acidity, alcohol, and residual sugar content. In addition, elemental composition, phenolic content, antioxidant capacity, and sensory attributes of the wines were assessed. The obtained results suggested that besides the type of wine and variety, the location significantly affects the quality parameters of the wine. PCA analysis revealed that location is an important factor affecting the wine quality. The areas north and northwest proved more suitable for specific varieties, as they produce wines with more distinct organoleptic characteristics. The results provide insights into the behavior of international and native varieties in the face of global warming and assist in decisions concerning the most suitable plant material. Full article

Besides the other factors, the microclimate (terroir) influences the quality characteristics of wine. The Assyrtiko variety has adapted to the volcanic soil of Santorini but under climate change, finding an ideal location for full grape ripening represents a challenge in preserving the PDO quality of Santorini wines. Thus, this study aims to evaluate the effect of location and harvesting time on the quality of Assyrtiko wine. It assessed the location effect (three distant plots of land in three distant areas of the island) on the composition of grapes (water uptake, pH, sugar, and organic acid accumulation) during the ripening. The grapes were vinified using the same procedure. The aromatic volatile profile of the wines was evaluated with GC-MS. A two-way ANOVA revealed that besides location and harvest time, their interaction is also significant for the parameters studied, except for the interaction effect involving sugar content. The analysis of volatile aromatic compounds revealed that the wine from grapes harvested at a later date had a higher aromatic intensity with notes of citrus, white-fleshed, and tropical fruits. This wine surpasses the levels of 2-phenylethanol, isoamyl acetate, linalool, and 2-phenylethyl ester with 17.8%, 7.7%, 21.1%, and 15.6%, respectively, compared to the immediate next in descending order. Results suggest that the grape variety is better suited to the local climatic conditions when full grape ripeness is reached by the end of the growing season. Full article

Greek wines made from the indigenous grape varieties Assyrtiko, Malagousia, Moschofilero and Roditis are attracting the interest of wine producers and consumers due to their aromatic characteristics. However, there are few studies that focus on the unique wine characteristics of each variety and the relationship between the composition of volatile compounds and sensory properties. Monovarietal white wines (2018 vintage) were analyzed by gas chromatography–mass spectrometry to quantify 34 volatile compounds. Multivariate statistical analyses were used to investigate correlations between volatiles and sensory attributes identified by a trained panel. The results showed that the strongest aroma compounds were a group of terpenes, isoamyl acetate and phenylethyl acetate. Terpenes such as geraniol, α-terpineol, linalool and cis-rose oxide correlated with floral notes, especially in Moschofilero wines. In addition, isoamyl acetate contributed to the aroma of tropical fruits, especially banana, in the Roditis wines, while phenylethyl acetate correlated with rose, vanilla and fruity notes in both the Moschofilero and Roditis samples. The Assyrtiko wines and the Malagousia wines were mainly associated with compounds such as cis-3-hexen-1-ol and cis- and trans-furan linalool oxides, which may enhance fresh fruit and citrus aromas through synergistic effects. The common background aroma of the studied wines was mainly determined by higher alcohols, fatty acids and ethyl esters. This study provides a basis for understanding the typical aroma of white wines from indigenous Greek grape varieties, which will help producers develop targeted wine styles and will be useful for consumer promotion. Full article

The honeydew moth, Cryptoblabes gnidiella Millière (Lepidoptera: Pyralidae), is native to the Mediterranean Basin. However, it has recently been reported as an emerging grapevine pest in southern European Union countries and in the Middle East, North Africa, and South America. This may be attributed to the global warming trends. In this brief communication, we present the first documented cases of honeydew moth infestation of grapevine in Greece, specifically in two organic vineyards in the Regional Unit of Drama in Northeastern Greece in 2024. Notably, the infestations were limited to the late-ripening grape cultivar ‘Xinomavro’, harvested in October, while other cultivars such as ‘Assyrtiko’, ‘Malagousia’, ‘Cabernet sauvignon’, ‘Sauvignon blanc’, ‘Limniona’, ‘Chardonnay’, and ‘Agiorgitiko’, harvested in late August and early September, showed no signs of infestation. This suggests that the actual impact of C. gnidiella in Greece may be underestimated, as previous late summer infestations of lepidopteran larvae in vineyards were likely misattributed to L. botrana. We discuss the potential implications and concerns regarding the occurrence and management of this pest in Greece. Full article

Adaptive laboratory evolution (ALE) is a non-GMO technique utilized for the amelioration of wine yeast strains. Employing two-step ALE strategies, we recently acquired six evolved Saccharomyces cerevisiae populations with improved fermentative abilities compared to their parental strains in synthetic broths. Herein, we evaluated the qualities of the abovementioned evolved populations under real winemaking conditions, using the grape musts Assyrtiko and Roditis. The ethanol-tolerant populations evolved solely with glucose delayed to complete the fermentation due to slow fructose assimilation, albeit showing improved ethanol yields, compared to their parental strains. The volatile compounds of the evolved populations were significantly different from those of parental strains. Statistically significant differences were observed in the organoleptic profiles between the evolved populations’ and parental strains’ wines. Notably, wine from one evolved population (BLR200) was rated higher in overall aroma and quality. This study supports the magnitude of ALE strategies for the generation of novel wine yeasts. Full article

Assyrtiko is a rare ancient grape variety of Greece, which is known to produce Protected Designation of Origin (PDO) Santorini white wines. Besides the famous character of the volcanic terroir, Assyrtiko of Santorini is also marked by a low pH value and sharp acidity. The aim of the present study was to apply a new inoculation procedure that modulates the fermentation process by maintaining the unique sensorial characteristics of Assyrtiko wines based on acidity. For this purpose, the Lachancea thermotolerans species, known for the formation of lactic acid, was tested in sequential fermentation with three different Saccharomyces cerevisiae strains. At the end of the fermentation process, implantation control for S. cerevisiae strains (interdelta sequence profile analysis) was performed, oenological parameters were determined according to the OIV protocols, and the volatile compounds produced were measured by gas chromatography–mass spectrometry (GC/MS). Finally, all produced wines were evaluated by quantitative descriptive analysis by two groups of experts; the Greek team of oenologists from Santorini Island specialized in Assyrtiko wines, and the French team of oenologists specialized in wine from Bordeaux. As expected, the inoculated strain was the one that dominated the fermentation process, but nine S. cerevisiae indigenous strains were also identified in the produced wines. Lachancea thermotolerans produced 1 g/L of lactic and also modulated the volatile profile of the wines independently of the S. cerevisiae strain used. The origin of the panelists played an important role in bringing up sensorial traits, such as acidity. Our results led to a new interesting application of L. thermotolerans for white wine production adapted to climate change claims. Full article

Vitis vinifera, an economically significant grapevine species, is known for wine, juice, and table grape production. The berries of wine grapes host a diverse range of microorganisms influencing both grapevine health and the winemaking process. Indigenous to Greece, the emblematic variety Assyrtiko, renowned for high-quality white wines, originated from Santorini and spread to various Greek regions. Despite existing studies on the microbiota of several varieties, the carposphere microbiota of Assyrtiko grapes remains unexplored. Thus, we conducted a spatiotemporal metagenomic study to identify the epiphytic microbial community composition of Assyrtiko grapes. The study was conducted in two consecutive vintage years (2019 and 2020) across three different and distinct viticulture regions in Greece (Attica, Thessaloniki, Evros). We performed amplicon sequencing, targeting the 16S rRNA gene for bacteria and the ITS region for fungi, with subsequent comprehensive bioinformatic analysis. Our data indicate that the distribution and relative abundance of the epiphytic carposphere microbial communities of the Assyrtiko variety are shaped both by vintage and biogeography. Full article