Search Results (132)

This study investigated young white wines produced during the 2021 and 2022 vintages from Pedro Ximénez grapes cultivated in three different terroirs within a high-quality production zone. The general oenological parameters were significantly influenced by vintage and terroir (p ≤ 0.001), with ethanol and reducing sugars specifically affected by the terroir and its interaction with the vintage. Multivariate analysis of major and minor volatile compounds enabled the characterization of terroir-specific volatile profiles. However, principal component analysis (PCA) grouped samples by vintage rather than terroir. Ethyl esters of medium- and long-chain fatty acids and certain acetates of higher alcohols were the most discriminant volatiles and were proposed as key compounds for differentiating wines by terroir and vintage. These findings underscore the influence of the terroir on the volatilome and support its relevance in defining wine typicity and quality. Full article

Wine vinegar and wine are traditional Spanish products, obtained from grape must by alcoholic fermentation (wine) and subsequent acetification (vinegar). Although these are established products, there is great interest in the development of new products, particularly new vinegars, and among these, the possibility of vinegars containing gluconic acid stands out. Gluconic acid in vinegar, mainly produced by acetic acid bacteria (AAB), is positively valued by consumers. Its content depends on the availability of glucose in the base wine; however, this hexose is preferentially consumed by the indigenous yeast population which conducts the previous alcoholic fermentation. For this reason, the use of non-conventional fructophilic yeasts, which consume fructose rather than glucose, is required. In this work, we isolated, screened, and identified osmophilic and fructophilic non-Saccharomyces yeasts from sun-dried grape must and tested them under different fermentation conditions in synthetic and natural grape musts, in order to obtain a base wine with ethanol and glucose content for the development of new vinegars containing gluconic acid. The isolate of the species Starmerella lactis-condensi was found to be an ideal candidate due to its fructophilic and osmophilic features, which allowed for the production of a base wine with high ethanol (11% v/v) and glucose (up to 200 g/L) content from a natural concentrated must. In fresh must, inoculation with Starmerella lactis-condensi resulted in faster and preferential fructose consumption over glucose compared to the control. However, both sugars were completely consumed at the end of the alcoholic fermentation; therefore, new fermentation strategies should be tested in this type of must. Furthermore, this strain could be of interest in oenology due to its high glycerol yield and low volatile acid production during alcoholic fermentation. The use of this strain could allow for the production of new wines with unique metabolic profiles suitable for further vinegar production. Full article

This study evaluated the oenological potential of two non-Saccharomyces yeast strains, Hanseniaspora opuntiae TR-5 and Zygosaccharomyces bailii L-25, isolated from extreme winemaking environments in southern Spain. Out of 156 yeast isolates screened from high-sugar musts and flor yeast biofilms, strains were selected based on their β-glucosidase activity, killer phenotype, and ethanol production, traits associated with aroma release and microbial competition. Fermentation trials on sugar-rich synthetic medium showed that both H. opuntiae and Z. bailii achieved ethanol yields of 10% v/v and residual sugars at 4 g/L. Co-culture and sequential inoculation, with H. opuntiae introduced first and Z. bailii added on day four, resulted in complete alcoholic fermentation and a reduction in undesirable acetoin levels compared to single-strain fermentations. These findings highlight the practical potential of using selected non-Saccharomyces strains in sequential fermentations to improve aroma complexity, fermentation reliability, and sensory quality in wines, even in the absence of Saccharomyces cerevisiae. The application of these strains offers a novel approach for precision oenology and varietal expression in challenging musts. Full article

Yellow passion fruit provides a substrate suitable for alcoholic fermentation and holds valuable sensory and nutritional properties that support its use for producing wine. Among the different interesting aspects to consider in the winemaking process, we highlight the analysis of the proteins of the yeast or yeasts responsible for the process; in addition to providing fundamental knowledge about the biotransformations that take place, they can contribute to understanding basic aspects that affect the sensory properties of the wine obtained. This study aimed to analyze the proteomic profile of the yeast Saccharomyces cerevisiae strain E1 (ATCC: MYC-425) during passion fruit fermentation. The process was conducted in a 5 L Sartorius bioreactor with a diluted fruit puree and sucrose, making a medium with a 10% v/v alcohol potential; after 4 days, ethanol reached 8.5% v/v as sugars decreased. Subsequent LC/MS-MS analysis allowed identifying a total of 938 valid proteins: 454 from the fruit substrate and 484 attributed to yeast. Of the latter, 243 proteins were present throughout the fermentation, with GO term analysis highlighting “binding” (78%) and “catalytic activity” (66%) in molecular function, as well as “cellular” (98%) and “metabolic (90%) processes” in biological process domains. These findings may be a significant step forward in understanding the proteomic dynamics of S. cerevisiae in tropical fruit fermentations. By revealing key proteins and their roles in the unique conditions of passion fruit must, this study offers insights for optimizing the wine elaboration procedures and improving organoleptic properties and quality. Full article

This study investigates nitrogen metabolism during the middle of the second fermentation in stopped bottles of sparkling wine, focusing on two flor Saccharomyces cerevisiae yeast strains (G1 and N62) isolated from the velum of biologically aged wine. Nitrogen compounds, including amino acids, biogenic amines, and ammonium chloride, were quantified, revealing strain-specific differences in nitrogen utilization and production. Proteomic analysis identified 1053 proteins, with 127 showing significant differences between strains. Strain G1 demonstrated enhanced cell wall remodeling and prioritized nitrogen conservation via arginine and lysine biosynthesis, while strain N62 exhibited increased translational activity and alternative carbon utilization pathways. Notably, strain N62 produced higher concentrations of biogenic amines (putrescine and tyramine), likely due to its greater decarboxylation capacity. Principal Component Analysis (PCA) highlighted clear differentiation in the nitrogen compound profiles across the base wine and wines inoculated with the two strains. The proteome of strain N62 showed increased mitochondrial activity and TCA cycle involvement, facilitating faster fermentation (27 days vs. 52 days for G1), growth (46 × 10⁶ cells/mL vs. 21 × 10⁶ cells/mL for G1) and cell viability (4 × 10⁶ cells/mL vs. 0.7 × 10⁶ cells/mL for G1). These findings suggest that yeast strain selection significantly influences nitrogen metabolism and potentially aroma profiles and and fermentation dynamics in sparkling wine production. Understanding these metabolic adaptations provides valuable insights for optimizing yeast performance to enhance wine quality and preserve regional characteristics. Full article

In an increasingly urbanized world, biodiversity, and more specifically, birdlife located in urbanized ecosystems, faces several threats. Among these, noise pollution has proven to be one of the most significant, as it affects the effectiveness and efficiency of acoustic communication. We studied the relationship between noise and the diversity and abundance of birds breeding in urban areas in the central region of the Iberian Peninsula (Spain). We analyzed how species diversity and density varied across three levels of noise pollution (high, medium, and low). Species diversity decreased in areas with high noise pollution as compared to sites with medium and low levels of noise. We analyzed the density of the most frequent species found within each category. We identified eight additional noise-tolerant species whose density had significantly increased in environments with high levels of noise (e.g., Blackbird, Eurasian Tree Sparrow, and the Coal Tit). The ten most sensitive species, such as the Common Linnet, House Sparrow, and the European Greenfinch, had significantly decreased densities when the level of noise increased. Identifying the sensitivity (the effect) of urban bird species to acoustic pollution is vital for effective conservation management measures and for the sustainable planning and management of cities. Full article

The environment is being affected by the great development of human activities, which is why, in recent years, the need to protect the environment has increased, through the carrying out of a Strategic Environmental Assessment (SEA). Within this assessment, environmental geology constitutes an instrument for territorial and urban planning based on the analysis of conservation and the integral analysis of risks, obtaining cartography that can be useful in territorial and regional planning strategies. The methodology carried out in this article consists of applying a multi-criteria analysis in territorial planning, combining vector and raster data. This novel, low-cost, and effective methodology assesses conservation areas and risks, using map algebra and network analysis to identify priority areas and facilitate decision-making in a precise and quantitative manner. This analysis has been carried out in the Arribes del Duero Natural Park, which stands out as a place where numerous environmental values coexist, i.e., geological, geomorphological, and edaphological, forming unique landscapes. With regard to the results obtained, the cartography of conservation quality classifies the territory into four categories according to its degree of conservation: very high, high, low, and very low quality. The integral risk cartography identifies the areas with the greatest geological risks, such as erosion and landslides, and establishes limitations for land use. Also, by integrating both cartographies, it is determined which activities are compatible with each zone, considering both conservation and risks. Finally, it can be concluded that the cartographies obtained are useful for efficient land management, protecting the environment, and allowing human development in a controlled manner. Full article

Bioplastics such as poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) are promising alternatives to conventional plastics. However, the high production cost limits their industrial application. In this study, PHBV production was optimized in Haloferax mediterranei by the homologous overexpression of the key enzyme PHA synthase (PhaEC), resulting in the OEphaEC strain. The growth and PHBV production of OEphaEC compared with the parental strain (HM26) were evaluated in three culture media with different nitrogen sources (KNO₃, NH₄Cl, and casamino acids). The OEphaEC strain exhibited a 20% increase in PHBV production and a 40% increase in 3-hydroxyvalerate monomer (3HV) content in a defined medium with nitrate as a nitrogen source, as determined by GC-MS. Moreover, enzyme activity, measured spectrophotometrically, increased from 2.3 to 3.9 U/mg. Soluble and insoluble protein fractions were analysed to assess the overexpression of PHA synthase. Only PhaE was found in the insoluble protein fraction, where PHBV granules accumulate. Transmission electron microscopy (TEM) images confirmed a higher PHBV content in OEphaEC compared to the parental strain. These results demonstrate that the homologous overexpression of the key enzyme implicated in PHBV biosynthesis can enhance PHBV content, making its production competitive for industrial applications. Full article

The effects of spontaneous fermentation and the inoculation of grape must with a flocculant yeast starter culture, together with the supplementation of must with a commercial organic nitrogen compound (ONC), were analyzed. The microbiome during fermentation was tracked, and volatile compounds in the resulting wines were identified and quantified using gas chromatography and mass spectrometry (GC-MS). Volatile compound concentrations were then subjected to statistical analysis. No significant differences in pH, titratable and volatile acidity, and ethanol and lactic acid were observed among the four wines analyzed. However, the musts supplemented with the ONC slightly increased the fermentation rate of the flocculant yeast, and, also, this additive reduced the volume of lees in the spontaneous fermentation and flocculant yeast by 1.2% and 0.6%, respectively. The concentrations of 11 major and 28 minor volatiles were significantly influenced (p-value ≤ 0.05) by the inoculation strategy, while 8 major and 28 minor volatiles were affected by ONC supplementation. This supplementation significantly decreased the Odor Activity Values and, consequently, the values of the odorant series established in wines from spontaneous fermentation. On the contrary, those from flocculant yeast showed a significant increase in all the odorant series except for the waxy series, leading to a more balanced aroma profile. Additionally, lower scores were recorded for the green, creamy, citrus, chemical, and honey series compared to wines from spontaneous fermentation. Overall, the commercial ONC extract contributed to a content increase in volatiles that provided desirable aromatic notes to the wines made with flocculant yeast, although the organoleptic evaluation showed no significant statistical differences in the attributes evaluated at the 95% confidence level. Full article

The nutrient uptake of a species under cultivated conditions is important for program fertilization. The Jaltomata genus has two semidomesticated species, J. procumbens and J. tlaxcala, used as food and considered with potential for their study in controlled environments. The objective of this research was to determine nutrient uptake curves of these species in a greenhouse and using hydroponics. The research was carried out at the Colegio de Postgraduados, Campus Montecillo, Texcoco, State of Mexico, from August to November 2020. The treatments included the following: two species and three electrical conductivity levels: 1, 2, and 3 dS m⁻¹. Nutrients in leaf and total dry matter (TDM) were determined. Variability between species and phenological stages on the nutrient concentration and accumulation of TDM was observed. For macronutrients, J. procumbens concentrated in descending order more P from the vegetative stage (4.21–2.43 g kg⁻¹ dry matter), and Mg until fructification (4.92–3.26 g kg⁻¹ dry matter), for K it was higher at vegetative (52.29 g kg⁻¹ dry matter) and harvesting stages (26.05 g kg⁻¹ dry matter), and N (23.92 g kg⁻¹ dry matter) at flowering; J. tlaxcala concentrated more Ca from fructification (10.10–13.85 g kg⁻¹ dry matter). For micronutrients, J. tlaxcala concentrated more Fe from the vegetative stage (157.7–207.5 mg kg⁻¹ dry matter), B and Zn at 23.3–38.4 and 26.04–28.45 mg kg⁻¹ dry matter, respectively, from flowering, and Mn (108.4–232.28 mg kg⁻¹ dry matter) from fructification. The main structures of TDM accumulation by vegetative stage in J. procumbens were the leaf and root (vegetative and flowering), root and stem (fructification), and reproductive structures and root (harvesting); in J. tlaxcala, the main structures were the leaf and root (vegetative), root and leaf (flowering and fructification), and root and reproductive structures (harvesting). Due to this variability, specific fertilization programs are required for each species. Full article

Electronic noses (E-noses) have become powerful tools for the rapid and cost-effective differentiation of wines, providing valuable information for the comprehensive evaluation of aroma patterns. However, they need to be trained and validated using classical analytical techniques, such as gas chromatography coupled with mass spectrometry, which accurately identify the volatile compounds in wine. In this study, five low-ethanol wines with distinctive sensory profiles—produced using Saccharomyces and non-Saccharomyces yeasts and tailored to modern consumer preferences—were analyzed to validate the E-nose. A total of 57 volatile compounds were quantified, 27 of which had an Odor Activity Value (OAV) over 0.2. The content in volatiles, grouped into 11 odorant series according to their odor descriptors, along with the data provided by 12 E-nose sensors, underwent advanced statistical treatments to identify relationships between both data matrices. Partial least squares discriminant analysis (PLS-DA) applied to the data from the 12 E-nose sensors revealed well-defined clustering patterns and produced a model that explained approximately 92% of the observed variability. In addition, a principal component regression (PCR) model was developed to assess the ability of the E-nose to non-destructively predict odorant series in wine. The synergy between the volatile compound profiles and the pattern recognition capability of the E-nose, as captured by PLS-DA, enables a detailed characterization of wine aromas. In addition, predictive models that integrate data from gas chromatography, flame ionization detection, and mass spectrometry (GC-FID/GC-MSD) with the electronic nose demonstrating a promising approach for a rapid and accurate odor series prediction, thereby increasing the efficiency of wine aroma analysis. Full article

Over the past quarter-century, the enhanced availability of satellite imagery, characterized by improved temporal, spectral, radiometric, and spatial resolutions, has enabled valuable insights into the spatial soil variability of annual croplands and orchards. This study investigates the impact of spatial resolution on classifying three-year, multi-temporal vegetation indices derived from satellites with coarse (30 m, Landsat 8), medium (10 m, Sentinel-2), and fine spatial resolutions (3.7 m, PlanetScope). The classification was performed using the fuzzy c-means algorithm, with the fuzziness performance index (FPI) and normalized classification entropy (NCE), which were used to determine the optimal number of management zones (MZs). Our results revealed that the Landsat 8-based NDVI images produced the highest number of clusters (nine for annual cropland and six for orchards), while the finer resolutions from PlanetScope reduced this to three clusters for both cultivation types, more accurately capturing the intra-parcel variability. Except for Landsat 8, the NDVI means of MZs generated based on Sentinel-2 and PlanetScope using the fuzzy c-means algorithm showed statistically significant differences from each other, as determined by a one-way and Welch’s ANOVA (p < 0.05). The use of PlanetScope imagery demonstrated its superiority in generating zones that reflect inherent variability, offering farmers actionable insights at a reconnaissance scale. Multi-temporal satellite imagery has proved effective in monitoring plant growth responses to edaphological soil properties. In our study, the PlanetScope satellites, which offer the highest spatial resolution, consistently produced effective zones for orchard areas. These zones have the potential to enhance farmers’ discovery of knowledge at a reconnaissance scale. With the increasing spatial resolution and enhanced spectral resolution of newer satellite sensors, using cluster analysis with insights from soil scientists promise to help farmers better understand and manage the fertility of their fields in a cost-effective manner. Full article

The rejection of chemical preservatives reflects the growing demand for natural and safe products. This concern has spurred scientific interest in yeasts as biocontrol agents, given their antagonistic activity against undesired fungi, which is one of the main problems associated with preservative reduction. Debaryomyces hansenii is a non-conventional yeast that has shown great potential for inhibiting filamentous fungi in the food industry. This study investigated the role of nutrient competition in the biocontrol activity of D. hansenii against unwanted molds. Potentially pathogenic molds from spoiled food were isolated using different media and identified using Sanger sequencing. The inhibitory effects of different autochthonous D. hansenii strains under varying nutrient conditions were assessed against isolated molds using semipermeable membranes. Inhibition activity was measured by assessing mycelial expansion and spore production using image software analysis and classical cell counting using a Neubauer chamber. The results indicated that D. hansenii effectively inhibited mold growth and sporulation, with the autochthonous strains LR2 and SRF1 showing higher inhibitory activity than the control strain CBS767. The effectiveness of inhibition varied with the yeast–mold combination, highlighting the need for a species-specific analysis. Nutrient competition plays a complementary role in D. hansenii biocontrol but does not directly impact overall inhibition. This suggests that other mechanisms, such as direct cell interactions or metabolite production, may be crucial. These findings enhance our understanding of the potential of D. hansenii as a natural preservative and advance biocontrol methods for food safety. Full article

In this research, the differences between two terroirs belonging to the Protected Designation of Origin (PDO) Montilla–Moriles (Spain) were analyzed. Both areas share soil and climate characteristics, grape varieties, viticultural practices, and winemaking processes. Therefore, the objective of this study was to establish differences between both areas based on the microbiome of the must, the oenological parameters, and the majority and minority volatile compounds of the wines, thus determining the identity traits that make the wines from both areas so different. The results obtained are quite revealing, since at the microbiome level qualitative differences were established between the various areas. In the quality area, the predominant species is Torulaspora delbrueckii while in the production area it is Hanseniaspora opuntiae. Regarding the volatilome, it was observed that the aromatic profile of the wines from the production area has more citrus-fruity aromas and the quality area has honey-floral aromas, thus producing unique wines from each of the areas. Full article