Search Results (36)

As compared to red wine technology, where pomace is macerated, the grape juices and musts are obtained by pressing the grapes and removing the pomace, thus removing an important source of antioxidant molecules. The objective of this study was to exploit the bioactive compounds from the black grape pomace and obtain a new food product, namely pasteurized red must with improved health-promoting properties. The study was conducted on four grape varieties for red wines—Fetească Neagră, Cabernet Sauvignon, Blauer Zweigelt, and Arcaș—each coming from a certain recognized Romanian vineyard, as follows: Murfatlar, Dealu Mare, Ștefănești-Argeș, and Iași, respectively. Both the must and the pomace extract used for each product were from the same variety and region. The recovery of polyphenols was achieved by macerating the pomace at ambient temperature, using solutions of ethanol in concentrations of 25%, 50%, and 75%. The results showed that the most efficient method of polyphenol recovery was obtained by using the ethanolic solution of 50%, which was selected for the subsequent stages of the study. The selected hydroalcoholic extract was concentrated by eliminating the solvent by roto evaporation and used as a source of supplementary bioactive compounds for the pasteurized must. The phenolic profiles of the musts enriched with phenolic extracts were determined by liquid chromatography, UHPLS-HRMS, revealing significant increases in the content of individual phenolic acids and other polyphenols. The phenolic extract recovered from the pomace significantly optimized the phenolic quality of the pasteurized must, thus contributing to the improvement of its nutritional value. The new product has a phenolic profile close to that of a red wine, but does not contain alcohol. Also, this technology is a sustainable method to convert grape waste into a safe, antioxidant-rich grape juice with potential health benefits. Full article

Grapes are commonly processed into shelf-stable products such as raisins, wine, juice, and syrup-canned syrup goods. During processing, byproducts like skins and seeds are generated, which contain bioactive compounds including polysaccharides and polyphenols that exhibit diverse biological activities. The objective of this work was to thoroughly evaluate the impact of ultrasound technology on both the extraction efficiency and in vitro hypoglycemic activity of the polysaccharides derived from grape skin. The isolation and purification of the polysaccharides were carried out using chromatographic column techniques, and the monosaccharide components were determined through HPLC. The hypoglycemic activity of the polysaccharides from grape skin in vitro was analyzed in vitro considering their inhibitory effects on α-amylase and α-glucosidase. The polysaccharides from grape skins were extracted via an ultrasound-assisted methodology (under the following conditions: 50 °C, 50 min, 20 mL/g ratio, and 210 W), resulting in an 11.82% extraction yield of GSPs. Monosaccharide constituent analysis revealed that GSP-1-1 consisted of galacturonic acid, arabinose, rhamnose, galactose, glucose, glucuronic acid, mannose, and xylose in a molar ratio of 40.26:26.99:13.58:12.2:2.24:1.97:1.63:1.42. In vitro evaluations indicated that both GSP and GSP-1-1 exhibited notable suppression of α-amylase and α-glucosidase activities, two key enzymes in carbohydrate digestion. This dual inhibitory action positions these compounds as potential therapeutic agents for blood glucose management strategies. This work provides a new direction for addressing the byproducts of the grape canning industry and also offers a theoretical basis for the development of functional grape products. Full article

Background: Wine production generates significant amounts of grape marc, which can serve as a potential source of bioactive compounds, including polyphenols. Objectives: In this study, we aimed to investigate the polyphenol content of skin and seeds separated from grape marc, and test their extracts against two significant bacteria, Listeria monocytogenes (LM) and Staphylococcus aureus (SA). Methods: A comprehensive analysis of the phenolic composition in the skin, seeds, and juice/wine derived from Cabernet Sauvignon grape berries was conducted over an 18-day fermentation period. High-performance liquid chromatography was performed to identify and quantify the main flavan-3-ols, flavonols, anthocyanins, and stilbenes. In addition, the total phenolic content (TPC) was determined by the Folin–Ciocalteu method. Results: The TPC of both seeds and skins significantly decreased over time. In parallel, the TPC in the wine gradually increased, indicating a release of phenolic compounds into the wine. We found that the TPC in seeds was consistently higher than in the skin at all examined time points. The main flavonoids in seeds were flavan-3-ols (catechin and epicatechin), while anthocyanins (delphinidin-, cyanidin-, petunidin-, peonidin-, and malvidin-3-O-glucoside) were the predominant ones in skins. Crude seed and skin extracts enriched in phenolics were prepared, of which only the crude seed extract was proven effective against LM and SA. Following the time-kill assay, our findings revealed that the minimal bactericidal concentration of the crude seed extract against LM was 5.02 mg/mL after 12 h incubation, demonstrating the eradication of the living bacterial cell number by ~6 log. A 24 h exposure time was required for complete inactivation of SA, but a lower concentration was sufficient (2.54 mg/mL). Conclusions: Grape waste remains a valuable source of polyphenols, with grape seeds, in particular, exhibiting significant antimicrobial activity against certain foodborne pathogens. Full article

Polyphenols are essential bioactive compounds that contribute to the nutritional and sensory properties of grape juice and wine. This study investigates the impact of ultrasound-assisted maceration (UAM) compared to traditional maceration (TM) techniques, under both warm and cold conditions, on the polyphenol content, physicochemical properties, and microbial counts of juice from Vitis vinifera L. Ultrasound-assisted maceration significantly enhanced the extraction of polyphenols, including anthocyanins, flavonols, flavan-3-ols, and stilbenes, within a shorter processing time. The total polyphenol content increased up to 689.3 mg/L under UAM, while TM required extended maceration periods to achieve comparable results. In addition to polyphenol enrichment, UAM resulted in improved physicochemical properties, including higher extract content (% Brix) and increased turbidity (NTU), with minimal impact on pH and acidity levels. Microbial counts in juice remained low under UAM, indicating that this method may also have antimicrobial benefits due to the cavitation effects of ultrasound. Conversely, TM under warm conditions led to a reduction in extract content and nitrogen availability due to fermentation processes initiated during prolonged maceration. The findings highlight that UAM is a highly efficient technique for enhancing the polyphenol profile of grape juice while preserving key physicochemical parameters and microbial decontamination. This study provides valuable insights for the beverage industry, suggesting that UAM can be a sustainable and time-efficient alternative to traditional maceration methods for producing high-quality grape-based beverages. Full article

This study investigates the effects of four enzymatic treatments on the yield, physicochemical properties, and bioactive compounds of grape juices from two red (Golubok, Regent) and two white (Muscaris, Aurora) hybrid grape varieties. A total of 20 samples were prepared using four commercial enzyme formulations (Pectinex Ultra, Safizym Clear Plus, Safizym Press, and Rapidase color) applied at a concentration of 0.02% (w/w). The juices were evaluated for yield, total phenolic content, antioxidant capacities (ABTS, DPPH, FRAP), titratable acidity, turbidity, total soluble solids, and phenolic profile. The addition of enzymes significantly improved juice yield by 10% to 20%, with the effect varying depending on the type of enzyme and the variety of grapes. Pectinex Ultra was the most effective enzyme in reducing turbidity, while enzyme treatments had minimal impact on Brix levels and sugar concentration, which were primarily determined by the characteristics of each grape variety. The enzyme addition showed a minor influence on the titratable acidity of the juices, with slight increases observed in Muscaris, but the grape variety played a major role in determining the titratable acidity levels. Color parameters revealed that white grape juices (Muscaris and Aurora) were brighter than red varieties (Golubok and Regent). Additionally, enzyme treatments influenced the color, enhancing the red hues in red grape juices. Enzyme treatments also improved the antioxidant capacity of grape juices, especially in Aurora and Muscaris, although the effect on polyphenol content was more dependent on the variety of grapes, with red varieties showing higher levels of polyphenols than white varieties. These findings highlight the significant role of both enzyme treatments and grape variety in determining the quality and health-promoting properties of grape juice. Full article

The phenolic profile and antioxidant activity of whole grape juices from Vitis labrusca and Brazilian hybrids in two training systems were analyzed. Genotypes of V. labrusca (‘Bordô’ and ‘Isabel’) and Brazilian hybrids (‘IAC 138-22 Máximo’ and ‘BRS Violeta’) were grafted onto the rootstock ‘IAC 766 Campinas’ (106-8 ‘Mgt’ × Vitis caribaea) and trained on low and high trellis. After harvest, the grapes were destemmed and the berries macerated in a roller crusher. Following hot extraction without pressurization of the pomace and gentle pressing of the blend (skins, must, and seeds), the juices were bottled in amber glass bottles and pasteurized. The physicochemical and colorimetric parameters of the juices, as well as the levels of flavonoids, phenolic compounds, total monomeric anthocyanins, antioxidant activity, and polyphenolic profile, were evaluated. The juices were also subjected to sensory analysis (CAAE: 65549817.7.0000.5411). There was broad variation in all assessed characteristics. The results obtained demonstrate that the training system and grape genotype used in juice production are highly related to the presence of sugars, acidity, and bioactive compounds. Juices made from ‘Bordô’, ‘IAC 138-22 Máximo’ and ‘BRS Violeta’ grapes stood out from ‘Isabel’ juices, the main grape variety used in Brazilian juice and wine production. All juices contain bioactive compounds in considerable concentrations, indicating beverages with high antioxidant activity and, consequently, high biological potential, with the use of high trellis in vine cultivation potentially increasing concentrations. Full article

Purple grape juice produces a significant amount of grape pomace (GP) as a by-product, which can be reused as a raw material in producing craft beers with bioactive properties. The objective of this study was to produce craft beers with the addition of GP during the fermentation process to evaluate the incorporation of bioactive compounds, aiming at using a by-product generated in the production of grape juice. Craft beer was produced, incorporating GP at concentrations of 1%, 5%, and 10% (w/w), and the physicochemical, technological, bioactive, and sensory properties were evaluated. The beers with the highest concentrations of GP (10% w/w) exhibited higher bioactive concentrations, including phenolic compounds (308 mg GAE/L), flavonoids (0.05 g of quercetin/L), anthocyanins (754.6 mg cyanidin-3-glucoside/L), and antioxidant capacities, as measured by DPPH (1878.2 µM Trolox/L), ABTS (4294.5 µM Trolox/L), and FRAP (844.7 mg ascorbic acid/L) methods. Adding GP promoted lower brightness (62.2) and intensified the a*, b*, and chroma parameters (18.0, 10.1, and 20.6, respectively), with the pigments of GP contributing to changes in the color parameters. However, increased sedimentation was observed under both conditions analyzed (4 °C and 25 °C), due to the higher presence of particulate matter from GP (3.4% and 3.7%, respectively). In general, for sensory analysis, while the knowledge of beneficial effects did not significantly change emotional responses, there were distinct emotional profiles associated with different beer samples. Utilizing GP for the bioactivation of beer is a positive approach to enhance its overall properties and an effective way to address issues related to the disposal of this by-product. Full article

This study researched the combined effects of heat treatment and varying concentrations of the pectolytic enzyme on the improvement of yield, color, and extraction of sugars, acids, and bioactive compounds of the ‘Merlot Kanthus’ grape juice. Application of low (0.05 IU/mL) and high (0.09 IU/mL) enzyme treatment substantially increased the yield of unpasteurized and pasteurized juice. Color intensity significantly improved in the pasteurized juice with a high enzyme concentration (CIRG 4.4) and the pasteurized juice without enzymes (4.5). No considerable differences in the total sugar concentration between the treatments were observed; however, the concentration of organic acids was improved by 27 and 13% in unpasteurized and pasteurized juice with a high enzyme concentration, respectively. A total of 78 individual phenolic compounds were identified, and the treatment with a high enzyme concentration had the most notable effect on the total anthocyanins, improving their concentration by 33.6% and increasing the concentration of 18 individual compounds. The heat treatment increased flavonol concentration by 41%. Overall, heat and enzyme treatment, mainly the high enzyme concentration, had a very favorable effect on the parameters of the analyzed ‘Merlot Kanthus’ grape juice, with a significant increase in the yield of bioactive components. Full article

Melatonin is commonly found in various fruits, juices, and some fermented beverages. Its concentration in wine is influenced by soil properties, climatic factors, and yeast activity. Even if it is found in fermented beverages in relatively low proportions, melatonin still holds significant nutritional value, giving anti-aging properties, anti-inflammatory actions, and antidepressant effects. In this context, this article focuses on evaluating the impact of different Saccharomyces and non-Saccharomyces yeast species on the formation of melatonin and its contribution to wines’ total antioxidant capacity. Considering that the antioxidant activity of wine is usually related to the content of phenolic compounds, ten such compounds were analyzed. The evaluation of bioactive compounds was performed using high-performance liquid chromatography (HPLC) coupled with mass spectrometry. The total antioxidant capacity of wine samples was evaluated by the ABTS⁺ method. The administration of bâtonnage products increased the efficiency of non-Saccharomyces yeasts. The mixtures of Saccharomyces and non-Saccharomyces yeasts generated higher values for melatonin. The results confirm a significant impact from the grape variety and the specific yeast strains on the melatonin concentration. Also, a strong dependence between antioxidant activity and melatonin levels was observed. Given the limited existing studies on the presence of melatonin in wines, new perspectives are needed for future exploration and understanding. Full article

Food and beverages with healthy and functional properties, especially those that prevent chronic diseases, are receiving considerable interest among consumers and researchers. Among the products with enhanced properties, fermented beverages from non-grape wines have a high potential for growth. Pomegranate (Punica granatum L.) is a super fruit known for its richness in bioactive compounds that have been reported to have several therapeutic properties against non-communicable diseases. Diverse products can be obtained from the valorization of pomegranate fruit, including wines, supplements, dried arils, juices, vinegar, and syrup. There is no literature evidence of the optimization of the fermentation processes of pomegranate juice that explores the relationships between multiple factors and their interactions. This review provides an overview of the composition of pomegranate fruit and the related health benefits for human health. It also discusses the ways in which pomegranate wine fermentation is impacted by pre-fermentation and fermentation factors. Additionally, it highlights the different subjective and objective techniques for analyzing pomegranate wine quality and the advancement of technologies such as sensors to replace traditional methods of sensory evaluation. It provides comprehensive insights into how different fermentation factors interact and can improve the bioprocess, leading to the production of high-quality wine. Full article

In this study, five varieties of hybrid grapes were processed into juice to assess the influence of variety, destemming process and enzyme addition on juice quality, including yield, physicochemical properties and bioactive compounds. The results highlighted that while the processing methods had some impact on juice quality, the inherent grape variety remained the most significant factor. Although similar treatments were applied to all varieties, there were differences in the quality attributes of the juice. In general, red grape juice had a higher polyphenol content and antioxidant capacity than white grape juice. Four phenolic acids, eleven flavonols, five flavan-3-ols and five anthocyanins were identified. While the polyphenolic profile of each sample depended on the treatment and the variety, regardless of the variety, destemming was found to increase the yield by around 10–15%, while the addition of enzyme improved the yield by around 20–30%. Although the addition of enzymes led to a higher polyphenol content, it changed the color profile of the juice as a result of the pigment’s skin extraction. In contrast, the destemming process did not influence the color of the juice, but at the same time, it reduced the health benefits due to the removal of potential bioactive compounds from the stems. Full article

The effect of high hydrostatic pressure (HHP) and the proteolytic fraction P1G10 from papaya latex was studied to find out whether a synergy exists in the growth inhibition of Botrytis cinerea in grape juice, contributing to the improvement of conservation techniques and extending the shelf life and quality of food products. Grape juice (GJ) diluted to 16 °Brix with a water activity (a_w) of 0.980 was prepared from a concentrated GJ and used in this study. Results indicated a 92% growth inhibition of B. cinerea when exposed to 1 mg/mL of P1G10 and 250 MPa/4 min of pressure treatment. The proximate composition and antioxidant compounds present in the GJ were not significantly affected after the treatments. Eight phenolic compounds and two flavonoids in GJ were identified and quantified, with values fluctuating between 12.77 ± 0.51 and 240.40 ± 20.9 mg/L in the control sample (0.1 MPa). The phenolic compounds showed a significant decrease after the applied treatments, with the HHP sample having a content of 65.4 ± 6.9 mg GAE/100 mL GJ. In conclusion, a synergistic effect at moderate HHP of 250 MPa/4 min with the addition of P1G10 was observed, and the successful development of a stable and acceptable GJ product was possible. Full article

Type 2 diabetes mellitus is a major contributor to morbidity and mortality worldwide. This disease often leads to poor health outcomes, such as neuropathy and diabetic foot ulcers, and increased risk for comorbidities such as cardiovascular complications and renal disease. Lifestyle modifications including diet and physical activity interventions are often explored as prevention and management strategies for T2DM. It is well established that fruits are a rich source of fiber and a variety of phytochemicals, vitamins, minerals, and bioactive compounds that can help optimize human health. Unfortunately, many experts associate the consumption of fruit with a moderate to high glycemic index (GI), which leads to a spike in blood glucose and eventually elevated hemoglobin A1c (HbA1c). The purpose of this comprehensive review is to outline the current clinical literature on the relationship between fruit consumption and various indices of glucose metabolism. A variety of fruits have been clinically studied to determine this relationship, namely in the fresh form (e.g., berries, apples, watermelon, cherries, mangoes), dried fruits (raisins and dates), and juices (derived from cranberry, orange, grape, cherry, and pomegranate). Overall, intake of fruits and fruit-derived products is beneficial for healthy subjects and subjects with T2DM regarding their impact on glucose metabolism and other cardiometabolic markers (e.g., inflammatory responses, lipid profiles). Nonetheless, it is more advisable for diabetic patients to consume fresh or dried fruits rather than fruit-derived products. A special consideration needs to be attributed to both the amount of fruit intake with regards to their respective GI and glycemic load (GL), and when these fruits are consumed. Trials with more a comprehensive design and specific outcomes are required to reveal the mechanisms underlying the beneficial effects of fruit consumption on the T2DM population particularly. Full article

To enrich the flavor compounds and retain the content of polyphenolics in grape juice (GJ) under long-term storage, Lactiplantibacillus plantarum, Lactobacillus acidophilus, Lacticaseibacillus casei, and Lacticaseibacillus paracasei, were screened and the optimal fermentation conditions were determined as fermentation temperature of 41.2 °C for 24 h with an initial LAB density of 8.5 × 10⁶ CFU/mL. Surprisingly, the retention rates of TPC still remained at 50% after storage for 45 days at 4 °C. Moreover, 251 different metabolites were identified, include 23 polyphenolics, 11 saccharides, and 9 organic acids. Most importantly, the total content of polyphenolics reserved was 92.65% at the end of fermentation. Among them, ephedrannin A content significantly decreased; however, 2′,6′-Di-O-acetylononin gradually increased with the fermentation time, which resulted in FGJ maintaining excellent bioactivity. Meanwhile, organic acid content (palmitoylethanolamide, tetraacetylethylenediamine) increased with saccharides (linamarin) decreasing, which leads to FGJ having a unique taste. Furthermore, a total of 85 Volatile organic compounds (VOCs) were identified, mainly including esters, aldehydes, and alcohols. Interestingly, key VOCs could be formed by carboxylic acids and derivatives, and fatty acyls via complex metabolic pathways. Full article

The aim of this study was the elaboration of isotonic drinks rich in bioactive compounds and antioxidant activity using organic ingredients and without synthetic additives. Grape juice was used as a natural source of sugars and phenolic compounds, combined with lemon juice and natural flavors from herb and spice extracts. The ingredients were diluted in two types of water with different mineralization, to which three different determined concentrations of salts (sodium chloride and potassium chloride) were added. The beverages had a sugar content ranging from 72.73 ± 0.23 to 78.43 ± 0.06 g/L, total soluble solids between 4.23 ± 0.06 and 4.83 ± 0.29 °Brix, and total acids from 1.75 ± 0.02 to 2.39 ± 0.08 g/L. Generally, antioxidant activity was higher in the beverages flavored with herb and spice extracts, ranging from 3.28 ± 0.01 to 4.27 ± 0.09 µmols Trolox equivalent/mL. Color intensity showed an increase of up to 129.39% in all samples during the storage period, being higher in beverages prepared with high-mineral water and having high pH values. The results of sensory analysis revealed that the flavored beverages had higher values of global perception than the controls. Thus, the functional properties of grape juice have been increased, and these beverages can be alternative natural and healthy products because their formulation is based only on organic and natural ingredients. Full article