Search Results (19)

Agronomic management directly influences soil and berry quality in vineyards, a crop of global relevance. However, some knowledge gaps regarding the effects of management practices in traditional vineyards of the Itata Valley in Chile remain. This study evaluated the impact of contrasting management systems: non-managed País (PA), conventionally managed País (CPA), organically managed Cinsault (OCI) and organically managed Carmenere (OCA), on soil bioindicators, chemical composition and berry rheological properties. The results showed that organic management, such as OCA, resulted in 96% and 95% higher dehydrogenase and urease activities, respectively, while OCI exceeded CPA by 86% and 173% in arylsulfatase and phosphatase activities, respectively. The CPA treatment exhibited significantly higher available nitrogen compared with PA (231%), OCI (509%) and OCA (236%), as well as greater available phosphorus than OCI (503%) and OCA (413%). Regarding berry rheology, OCA displayed the highest pulp viscosity compared to OCI, although the differences among treatments were not statistically significant. Multivariate analysis associated CPA with higher soil chemical fertility, whereas organic systems (OCI and OCA) were related to greater soil bioactivity and fruit viscosity. Therefore, organic management is recommended to improve soil biological functionality and fruit structural stability, contributing to the long-term sustainability of vineyards in the valley. Full article

In this study, a green hydrothermal synthesis method was employed to produce Mn₃O₄ and Mn₃O₄/β-MnO₂ nanostructures using EET-50, an organic extract obtained from a by-product of Carménère wine production. The biomolecules in EET-50 acted as reducing agents due to their electron-donating functional groups, enabling nanostructure formation without the need for additional chemical reductants. Morphological characterization by SEM revealed that a KMnO₄/EET-50 mass ratio of 3:1 led to the synthesis of nano-octahedra alongside rod-like structures, with shorter reaction times favoring the development of isolated nano-octahedra ranging from 100 nm to 170 nm. Structural analyses by XRD and Raman spectroscopy confirmed the formation of mixed-phase Mn₃O₄/β-MnO₂ and Mn₃O₄ (hausmannite). Electrochemical performance tests demonstrated that Mn₃O₄ nano-octahedra exhibited a superior specific capacitance of 236.27 F/g at 1 mA/g, surpassing the mixed-phase sample by 28.3%, and showed excellent capacitance retention (99.98%) after 100 cycles at 8 mA/g. Additionally, the Mn₃O₄ nano-octahedra exhibited enhanced oxygen evolution reaction performance in alkaline media, with an overpotential of 0.430 V vs. RHE and a Tafel slope of 205 mV/dec. These results underscore the potential of Mn₃O₄ nano-octahedra, synthesized via a green route using grape pomace extract as a reducing agent, offering an environmentally friendly alternative for applications in energy storage and electrocatalysis. Full article

Grape pomace is a major by-product of winemaking and a rich source of phenolic compounds with antioxidant potential. The Carménère variety, emblematic of Chilean viticulture, remains underutilized despite its high anthocyanin and flavanol content. This study aimed to develop a cost-effective method to recover and stabilize bioactive compounds from Carménère grape pomace. Five extracts were obtained using ethanol–water mixtures (0–100%) and characterized by HPLC-DAD and antioxidant assays (DPPH, FRAP, ORAC-FL). The 80% ethanol extract (EET-80) showed the highest antioxidant capacity (FRAP: 2909.3 ± 37.6; ORAC-FL: 1864.3 ± 157.8 µmol TE/g dw) and was selected for microencapsulation via spray drying using maltodextrin. This scalable technique protects thermosensitive compounds and enhances their applicability. The optimized 1:50 extract-to-carrier ratio achieved high encapsulation efficiency (85.7 ± 0.7%). In Caco-2 cells, the microencapsulated extract (5–250 µg/mL) showed no alteration in metabolic activity and significantly reduced intracellular ROS levels (65% inhibition at 250 µg/mL). Solvent polarity selectively influenced polyphenol recovery—50% ethanol favored catechin (581.1 µg/g) and epicatechin (1788.3 µg/g), while 80% ethanol enhanced malvidin-3-O-glucoside (118.0 µg/g). These findings support the valorization of Carménère grape pomace as a sustainable source of antioxidants and highlight the role of microencapsulation in improving extract stability and functionality. Full article

The differentiation of clones within grape cultivars, specifically Vitis vinifera, has significant potential for the wine industry. This differentiation involves associating morphological features or a genetic signature with a particular cultivar clone, which is a challenging task. It has been difficult to experimentally find genetic signatures that differentiate a pair of clones, despite evidence suggesting that genomic differences exist. Are there genetic or genomic differences in a pair of clones? If so, where are the variations in the genome? Are there variations in protein coding genes? We addressed these questions by performing a bioinformatic analysis to identify genetic differences between certified clones of the same cultivar. Utilising genome sequencing data from tissue samples, we identified genomic positions differing between the clones and their cultivar reference genome, meeting the filtering criteria. Applying this approach to the Carménère and Merlot clones resulted in 5718 and 5218 variations, respectively, that differentiated the clones. Visual validation of 50 variations per cultivar revealed that 12% of these variations were located in the Merlot genes, while 32% were found in the Carménère genes. We estimated between 600 and 1000 variations per cultivar that could be validated by visual inspection. Despite the presence of these variations within genes, none was found to have a disruptive effect on protein function. By comparing our results with those of previous studies, we discuss issues pertaining to clone differentiation. In conclusion, there are genomic variations in pairs of clones that allow for their differentiation, though the variations are not directly related to the phenotype. Full article

The recovery of valuable compounds like phenolic compounds and sugars from grape marc extracts implies different steps, including clarification. In this study, a response surface methodology (RSM) was used as a statistical tool to study the effects of operating conditions such as transmembrane pressure (TMP), temperature and feed flow rate on the performance of a microfiltration (MF) monotubular ceramic membrane with a pore size of 0.14 μm in the clarification of grape marc extract from the Carménère variety, as well to optimize the process conditions by implementing the Box–Behnken statistical design. The desirability function approach was applied to analyze the regression model equations in order to maximize the permeate flux and concentration of malvidin-3-O-glucoside, glucose and fructose in the clarified extract. The optimal operating conditions were found to be 1 bar, 29.01 °C and 5.64 L/min. Under these conditions, the permeate flux and concentration of malvidin-3-O-glucoside, glucose and fructose resulted in 65.78 L/m²h, 43.73 mg/L, 305.89 mg/L, and 274.85 mg/L, respectively. Full article

Deep eutectic solvents (DES) are emerging as potent polyphenol extractors under normal atmospheric conditions. Yet, their effectiveness in hot pressurized liquid extraction (HPLE) must be studied more. We explored the ability of various water/DES and water/hydrogen bond donors (HBDs) mixtures in both atmospheric solid liquid extraction (ASLE) and HPLE (50%, 90 °C) for isolating specific polyphenol families from Carménère grape pomace. We assessed extraction yields based on total polyphenols, antioxidant capacity, and recovery of targeted polyphenols. The HBDs ethylene glycol and glycerol outperformed DES in atmospheric and pressurized extractions. Ethylene glycol exhibited a higher affinity for phenolic acids and flavonols, while flavanols preferred glycerol. Quantum chemical computations indicated that a high-water content in DES mixtures led to the formation of new hydrogen bonds, thereby reducing polyphenol-solvent interactions. HPLE was found to be superior to ASLE across all tested solvents. The elevated pressure in HPLE has caused significant improvement in the recovery of flavanols (17–89%), phenolic acids (17–1000%), and flavonols (81–258%). Scanning electron microscopy analysis of post-extraction residues suggested that high pressures collapse the plant matrix, thus easing polyphenol release. Full article

SSR (simple sequence repeat) DNA markers are widely used for genotype DNA identification, QTL mapping, and analyzing genetic biodiversity. However, SSRs in grapes are still in their early stages, with a few primer pairs accessible. With the whole-genome sequencing (WGS) of several grape varieties, characterization of grape SSR changed to be necessary not only to genomics but to also help SSR development and utility. Based on this, we identified the whole-genome SSR of nine grape cultivars (‘PN40024’, ‘Cabernet Sauvignon’, ‘Carménère’, ‘Chardonnay’, ‘Merlot’, ‘Riesling’, ‘Zinfandel’, ‘Shine Muscat’, and ‘Muscat Hamburg’) with whole-genome sequences released publicly and found that there are great differences in the distribution of SSR loci in different varieties. According to the difference in genome size, the number of SSRs ranged from 267,385 (Cabernet Sauvignon) to 627,429 (Carménère), the density of the SSR locus in the genome of nine cultivars was generally 1 per Kb. SSR motif distribution characteristic analysis of these grape cultivars showed that the distribution patterns among grape cultivars were conservative, mainly enriched in A/T. However, there are some differences in motif types (especially tetranucleotides, pentanucleotides, and hexanucleotides), quantity, total length, and average length in different varieties, which might be related to the size of the assembled genome or the specificity of variety domestication. The distribution characteristics of SSRs were revealed by whole-genome analysis of simple repeats of grape varieties. In this study, 32 pairs of primers with lower polymorphism have been screened, which provided an important research foundation for the development of molecular markers of grape variety identification and the construction of linkage maps of important agronomic traits for crop improvement. Full article

Grape pomace (GP) is a by-product resulting from the winemaking process and its potential use as a source of bioactive compounds is well known. The GP bioactive compounds can be retained in the well-known polyvinylpolypyrrolidone (PVPP), industrially used in the clarification and stabilization of wine and other drinks. Thus, the polyphenolic compounds (PC) from the Chilean Carménère, Cabernet Sauvignon, and Merlot GP were extracted, and their compositions and antioxidant capacities (ORAC-FL) were determined. In addition, the retention capacity of the PC on PVPP (PC-PVPP) was evaluated. The bioactivities of GP extracts and PC-PVPP were estimated by the agar plate inhibition assay against pathogenic microorganisms. Results showed a high amount of TPC and antioxidant capacity in the three ethanolic GPs extracts. Anthocyanins, flavan-3-ol, and flavonols were the most abundant compounds in the GP extract, with retentions between 70 and 99% on PVPP. The GP extracts showed inhibition activity against B. cereus and P. syringae pv. actinidiae but the GP-PVPP had no antimicrobial activity. The high affinity of the identified PCs from GPs on PVPP polymer could allow the design of new processes and by-products for the food or cosmeceutical industry, promoting a circular economy by reducing and reusing wastes (GPs and PVPP) and organic solvents. Full article

Absorbed energy in excess of that used by photosynthesis induces photoinhibition, which is common in water deficit conditions, resulting in reductions in stomatal conductance. In grapevines, controlled water deficit is a common field practice, but little is known about the impact of a given water shortage on the energy transduction processes at the leaf level in relation to contrasting stomatal sensitivities to drought. Here, we assessed the effect of a nearly similar water deficit condition on four grapevine varieties: Cabernet Sauvignon (CS) and Sauvignon Blanc (SB), which are stomatal sensitive, and Chardonnay (CH) and Carménère (CM), which are less stomatal sensitive, grown in 20 L pots outdoors. Plants were maintained to nearly 94% of field capacity (WW) and 83% field capacity (WD). We have assessed plant water status, photosynthesis (A_N), photorespiration, A_N vs. PAR, AC_i curves, photochemical (qP) and non-photochemical (qN) fluorescence quenching vs. PAR, the photoprotective effectiveness of NPQ (qPd) and light interception by leaves. Photorespiration is important under WD, but to a different extent between varieties. This is related to stomatal sensitivity, maintaining a safe proportion of PSII reaction centres in an open state. Additionally, the capacity for carboxylation is affected by WD, but to a greater extent in more sensitive varieties. As for qN, in WD it saturates at 750 μmol PAR m⁻²s⁻¹, irrespective of the variety, which coincides with PAR, from which qN photoprotective effectiveness declines, and qP is reduced to risky thresholds. Additionally, that same PAR intensity is intercepted by WD leaves from highly stomatal-sensitive varieties, likely due to a modification of the leaf angle in those plants. Pigments associated with qN, as well as chlorophylls, do not seem to be a relevant physiological target for acclimation. Full article

(1) Background: Currently, some ampelographic methods are developing in order to identify grapevine varieties. For this purpose, morpho-colorimetric parameters in leaves have been analyzed by digital imagen analysis, but some environmental conditions may affect their determinations. (2) Methods: A research study was conducted to characterize leaf morpho-colorimetric parameters in five grapevine varieties growing under different plant water status and to discriminate them under these conditions. Leaves were collected in vines, and twelve leaf morpho-colorimetric and fractal dimension variables were assessed. (3) Results: Merlot presented the highest values of perimeter and area to perimeter ratio in leaves and higher leaf area than Chardonnay in both plant water conditions. Most of the leaf morpho-colorimetric variables allowed discriminating the grapevine varieties under the contrasted hydric conditions. Under non-water stress, Carmenère was not related to any measured parameters. Merlot was positively related to most of the leaf morphometric parameters, whereas Chardonnay presented the opposite behavior. RGB color system variables allowed discriminating the grapevine varieties under water stress conditions, and Sauvignon Blanc was not related to any measured parameter. Chardonnay and Pinot Noir were positively related to green color and negatively related to most of the leaf morphometric parameters, whereas Merlot showed the opposite behavior. (4) Conclusions: Leaf morpho-colorimetric and fractal dimension parameters were affected by plant water stress and more variables should be incorporated into the new ampelographic methods in order to characterize leaf morpho-colorimetric parameters of the different grapevine varieties more clearly. Full article

Wastewaters and by-products generated in the winemaking process are important and inexpensive sources of value-added compounds that can be potentially reused for the development of new products of commercial interest (i.e., functional foods). This research was undertaken in order to evaluate the potential of nanofiltration (NF) membranes in the recovery of anthocyanins and monosaccharides from a clarified Carménère grape marc obtained through a combination of ultrasound-assisted extraction and microfiltration. Three different flat-sheet nanofiltration (NF) membranes, covering the range of molecular weight cut-off (MWCO) from 150 to 800 Da, were evaluated for their productivity as well as for their rejection towards anthocyanins (malvidin-3-O-glucoside, malvidin 3-(acetyl)-glucoside, and malvidin 3-(coumaroyl)-glucoside) and sugars (glucose and fructose) in selected operating conditions. The selected membranes showed differences in their performance in terms of permeate flux and rejection of target compounds. The NFX membrane, with the lowest MWCO (150–300 Da), showed a lower flux decay in comparison to the other investigated membranes. All the membranes showed rejection higher than 99.42% for the quantified anthocyanins. Regarding sugars rejection, the NFX membrane showed the highest rejection for glucose and fructose (100 and 92.60%, respectively), whereas the NFW membrane (MWCO 300–500 Da) was the one with the lowest rejection for these compounds (80.57 and 71.62%, respectively). As a general trend, the tested membranes did not show a preferential rejection of anthocyanins over sugars. Therefore, all tested membranes were suitable for concentration purposes. Full article

Grape pomace polyphenols inhibit Type 2 Diabetes Mellitus (T2DM)-related enzymes, reinforcing their sustainable recovery to be used as an alternative to the synthetic drug acarbose. Protic co-solvents (ethanol 15% and glycerol 15%) were evaluated in the hot pressurized liquid extraction (HPLE) of Carménère pomace at 90, 120, and 150 °C in order to obtain extracts rich in monomers and oligomers of procyanidins with high antioxidant capacities and inhibitory effects on α-amylase and α-glucosidase. The higher the HPLE temperature (from 90 °C to 150 °C) the higher the total polyphenol content (~79%, ~83%, and ~143% for water-ethanol, water-glycerol and pure water, respectively) and antioxidant capacity of the extracts (Oxygen Radical Absorbance Capacity, ORAC), increased by ~26%, 27% and 13%, while the half maximal inhibitory concentration (IC₅₀) decreased by ~65%, 67%, and 59% for water-ethanol, water-glycerol, and pure water extracts, respectively). Water-glycerol HPLE at 150 and 120 °C recovered the highest amounts of monomers (99, 421, and 112 µg/g dw of phenolic acids, flavanols, and flavonols, respectively) and dimers of procyanidins (65 and 87 µg/g dw of B1 and B2, respectively). At 90 °C, the water-ethanol mixture extracted the highest amounts of procyanidin trimers (13 and 49 µg/g dw of C1 and B2, respectively) and procyanidin tetramers of B2 di-O-gallate (13 µg/g dw). Among the Carménère pomace extracts analyzed in this study, 1000 µg/mL of the water-ethanol extract obtained, at 90 °C, reduced differentially the α-amylase (56%) and α-glucosidase (98%) activities. At the same concentration, acarbose inhibited 56% of α-amylase and 73% of α-glucosidase activities; thus, our grape HPLE extracts can be considered a good inhibitor compared to the synthetic drug. Full article

Glycerol is a co-solvent for water extraction that has been shown to be highly effective for obtaining polyphenol extracts under atmospheric conditions. However, its efficacy under subcritical conditions has not yet been studied. We assessed different water-glycerol mixtures (15%, 32.5%, and 50%) in a hot pressurized liquid extraction system (HPLE: 10 MPa) at 90 °C, 120 °C, and 150 °C to obtain extracts of low molecular weight polyphenols from Carménère grape pomace. Under the same extraction conditions, glycerol as a co-solvent achieved significantly higher yields in polyphenols than ethanol. Optimal extraction conditions were 150 °C, with 32.5% glycerol for flavonols and 50% for flavanols, stilbenes, and phenolic acids. Considering gallic acid as a model molecule, computational chemistry calculations were applied to explain some unusual extraction outcomes. Furthermore, glycerol, methanol, ethanol, and ethylene glycol were studied to establish an incipient structure–property relationship. The high extraction yields of gallic acid obtained with water and glycerol solvent mixtures can be explained not only by the additional hydrogen bonds between glycerol and gallic acid as compared with the other alcohols, but also because the third hydroxyl group allows the formation of a three-centered hydrogen bond, which intensifies the strongest glycerol and gallic acid hydrogen bond. The above occurs both in neutral and deprotonated gallic acid. Consequently, glycerol confers to the extraction solvent a higher solvation energy of polyphenols than ethanol. Full article

Sequential extraction and purification stages are required to obtain extracts rich in specific polyphenols. However, both separation processes are often optimized independently and the effect of the integrated process on the global recovery of polyphenols has not been fully elucidated yet. We assessed the impact of hot-pressurized liquid extraction (HPLE) conditions (temperature: 90–150 °C; ethanol concentration: 15%–50%) on the global recovery of specific phenolic acids, flavanols, flavonols and stilbenes from Carménère grape pomace in an integrated HPLE/resin purification (RP) process. HPLE of phenolic acids, flavanols and stilbenes were favored when temperature and ethanol concentration increased, except for chlorogenic acid which showed an increment of its Gibbs free energy of solvation at higher ethanol contents. Ethanol concentration significantly impacted the global yield of the integrated HPLE/RP process. The lower the ethanol content of the HPLE extracts, the higher the recovery of phenolic acids, flavanols and stilbenes after RP, except for flavonols which present more polar functional groups. The best specific recovery conditions were 150 °C and ethanol concentrations of 15%, 32.5% and 50% for phenolic acids, flavanols and stilbenes, and flavonols, respectively. At 150 °C and 32.5% of ethanol, the extracts presented the highest total polyphenol content and antioxidant capacity. The integrated HPLE/RP process allows a selective separation of specific polyphenols and eliminates the interfering compounds, ensuring the safety of the extracts at all evaluated conditions. Full article

A trial was conducted during the 2005–2006 season in order to determine the effects of different leaf-to-fruit ratios on yield components and fruit composition in four Vitis vinifera L. cultivars. The treatments consisted of selecting shoots of four lengths (>1.3 m, 1.3–0.8 m, 0.8–0.4 m, and <0.4 m) with two crop levels (1–2 clusters/shoot), which allowed defining eight ratios. Berry composition and yield components were measured. The treatments affected the accumulation of soluble solids in “Sauvignon blanc”, “Cabernet Sauvignon”, and “Syrah”, delaying it as the ratio decreased. All yield components were affected in “Sauvignon blanc”, while bunch weight and the number of berries per bunch were altered without a clear trend. None of the yield components were affected in “Cabernet Sauvignon”, while the lowest ratio presented the lowest number of berries per bunch in “Syrah”. Total polyphenol index (TPI) was affected in “Carmenère” without a clear trend. A highly significant correlation was found between shoot length and leaf area in all studied cultivars. As the ratio increased, the shoot lignification increased in “Sauvignon blanc”. However, studies must be conducted during more seasons to establish better conclusions about the effects of leaf-to-fruit ratios on yield and fruit composition. Full article