Grape Extract Research Articles

EFFECT OF BLACK GRAPE EXTRACT ON CD4+ and CD8+ EXPRESSION IN MICE INFECTED WITH Salmonella typhimurium

Salmonelosis is a disease caused by the Salmonella sp. that causes a decrease in CD4+ expression. Black grape can boost the immune system through CD4+/CD8+ proliferation. The purpose of this study was to evaluate the activity of black grape extract to CD4+ and CD8+ expression in mice infected with Salmonella typhimurium. Research method is extract of black grapes, Salmonella typhimurium 108 infection, bacterial evaluation, extract therapy, flowcytometery examination, and 95% Anova test. The results of Anova test showed that the expression of CD4+ and CD8+ is not different. Biologically, an increase in CD4+ and CD8+ expression at doses of 100 mg/KgBB. A decrease in CD4+ and CD8+ expression at doses of 200 mg/KgBB and 400 mg/KgBB. Conclusion, biologically, black grape extract can increase the expression of CD4+ and CD8+ at low doses, as well as may decrease the expression of CD4+ and CD8+ at moderate to high doses.

Antifungal Activity Test of Ethanol Extracts and Ethyl Acetate and N-Hexane Fraction of Sea Grapes (Caulerpa Racemosa) on the Growth of the Fungi Trichophyton mentagrophytes

BACKGROUND: Sea grape (Caulerpa racemosa) is one of the marine plants that produce active compounds that can be used as medicinal ingredients with antifungal properties to inhibit fungal growth. AIM: The purpose of this study was to determine whether the ethanolic extract of the ethyl acetate fraction and n-Hexane of sea grapes taken from Kampung Terih, Riau Islands could inhibit the growth of the fungus Trichophyton mentagrophytes. METHODS: The antifungal activity was tested using the paper disk diffusion method with variant concentrations of ethanol extract, namely, 25%, 50%, 75%, and 100%, ethyl acetate and n-hexane fractions were 20,000 ppm, 30,000 ppm, 40,000 ppm, and 50,000 ppm. RESULTS: The results showed that the ethanolic extract of sea grapes could inhibit the growth of T. mentagrophytes fungus with the formation of an average diameter at each concentration of 0 mm; 3.4 mm; 5.4 mm; and 8.4 mm. The ethyl acetate fraction of Sea grapes formed an average diameter at each concentration of 9.7 mm; 11.51 mm; 13.5 mm; 15.8 mm. CONCLUSION: Based on the results of the study, it was concluded that the ethanol extract and the ethyl acetate fraction of sea grapes could inhibit the fungus T. mentagrophytes with moderate inhibition, while the n-hexane fraction of sea grapes could not inhibit the fungus T. mentagrophytes.

Effects of Almond Porridge, Grape Extract, and Pea Syrup on Fatigue Severity of Patients with COVID-19

Effects of Almond Porridge, Grape Extract, and Pea Syrup on Fatigue Severity of Patients with COVID-19

Aqueous extract of grapes stems for mild steel protection in 0.5 M NaCl

Mild steel (MS) is consumed on high scale in engineering applications due to its good operational properties and cost effectiveness. However, chloride attack on MS can damage its properties and affect its service performance. In present work, the water extract of grapes stems (WEGS) is used to inhibit corrosion of MS in 0.5 M NaCl. WEGS is investigated through Fourier transform infrared spectroscopy (FTIR) and WEGS is found to contain numerous functional groups. The corrosion investigation is done by electrochemical impedance spectroscopy (EIS), open circuit potential (OCP), Tafel polarization curves (TPC), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDX). The corrosion results favoured the fact that WEGS is inhibiting MS corrosion. This fact is also supported by FESEM and EDX analysis. The reason of corrosion inhibition is proposed as covering of MS surface by WEGS molecules.

Antitumor effects of table grape extracts

Grape (Vitis vinifera L.) is a fruit rich in polyphenols, bioactive compounds able to prevent cancer, reduce tumorigenesis, and influence critical cancer-related pathways. This research shows the main results obtained in our previous works: 1) the characterization of the polyphenolic content and antioxidant activity of two table grape skin extracts (GSEs), Autumn Royal, and Egnatia; 2) the GSEs effects on Caco2 colon cancer cell; 3) the effects of GSEs on the lipid composition and the fluidity of the cell membrane. These in vitro studies suggested that Autumn Royal and Egnatia contain high levels of polyphenols, possess antiproliferative activity on the Caco2 human colon carcinoma cell line and inhibit cell migration by acting on membrane fatty acids composition. Moreover, these results highlighted that the new grape variety Egnatia is an exciting source of phenolic compounds that could interest the food and pharmaceutical industries.

OPTIMIZATION OF THE COMPOSITION OF THE EXTRACTANT MIXTURE FOR THE EXTRACTION OF NATURAL ORGANIC COMPOUNDS FROM PROCESSING PRODUCTS OF VEGETABLE RAW MATERIALS AND THEIR FURTHER USE IN THE PRACTICE OF ANTI-CORROSION PROTECTION

Purpose. To theoretically substantiate and experimentally confirm the conceptual approach to the use of the i-PrOH-EtOH-H2O extractant system for obtaining plant extracts of grape, apricot, peach and tomato pomace with multifunctional anti-corrosion purposes. Methodology. The optimization of the three-component composition of the extractant system was carried out by the Scheffe simplex grid planning method with the construction of concentration triangles, the quantitative content of the sum of phenolic compounds, the total content of flavonoids, and the sum of volatile compounds was used as a response function, and the “composition-anticorrosion efficiency” dependence was established in neutral water and air environments. Scientific novelty. Use of the i-PrOH-EtOH-H2O extractant system in the ratio of propanol - 50 ÷ 40 %; ethanol – 25 ÷ 30 %; water – 15 ÷ 25 % with a polarity index ~ 5.9 ÷ 6.3, is a criterion parameter for the extraction of substances that belong to different groups of natural organic compounds: plants secondary metabolism terpene and polyphenolic compounds. Conclusions. It was established that the optimal use of the i-PrOH-EtOH-H2O extractant system with a percentage ratio of solvents in the range of 50-40 %; 25 ÷ 30 %; 15 ÷ 25 %, respectively. The calculated polarity index is in the range of ~ 5.87 ÷ 6.37 and is a criterion parameter for the system of extractants relative to the studied raw materials. By comparing the areas of optima with the construction of simplex lattice plans where the inhibitory effect is selected as the response function, it was established that the criterion parameters of the component composition of the extracts for their use as multifunctional inhibitors are the total content of phenolic compounds at the level of ~90 ÷ ≥150 mg of the extract, flavonoids ~ 22 ÷ ≥56 mg of extract and 70 ÷≥ 96 mg of terpene compounds per 100 g of extract.

Effect of commercial plant extracts on the oxidative stability of mechanically deboned poultry meat during chilled storage

The effect of commercial plant extracts (grape, rosemary, pomegranate, green tea, and mate) at 0.125, 0.25, 0.50, and 1 % w/w concentrations as a natural antioxidant in mechanically deboned poultry meat (MDPM) was evaluated. The extracts were characterized for the content of phenolic compounds, total flavonoids, and antioxidant activity. Lipid oxidation (TBARS), instrumental color (L*, a*, and b* values), and pH of MDPM were evaluated on days 0, 2, 4, 6, 8, and 10 of chilled storage (2 °C). All commercial extracts showed antioxidant activity in the following order: grape > green tea > mate > rosemary > pomegranate, the latter addition promoted the highest TBARS values in MDPM during storage. The levels of 0.5, 0.25, and 0.125 % of grape, green tea, mate, and rosemary extracts showed the same positive effect in decelerating lipid oxidation in MDPM. The pH values of the MDPM decreased with increasing the extract concentrations. The commercial extracts led to a decrease in L* and b* values, and the grape extract provided the highest a* values in MDPM during chilled storage. The addition of commercial plant-derived extracts has proven to be an effective natural antioxidant to extend the shelf life of MDPM and consequently healthier and quality meat products can be produced.

Comparative Efficacy of Aqueous Extracts of Lime (Citrus aurantifolia) and Grape (Citrus paradisi) Peel in the Control of Callosobruchus maculatus (F.)

A laboratory study was conducted in the Department of Crop Protection, University of Ilorin, to evaluate the single and mixed insecticidal action of aqueous extracts of grape (Citrus paradisi) and lime (Citrus aurantifolia) peel in the control of cowpea beetle, Callosobruchus maculatus. The experiment was laid out in a completely randomized design. There were four treatments with three replicates per treatment. The treatments were applied at the following rates, 0.5ml, 1.0ml, and 1.5ml per 100g of cowpea seeds. The following parameters were used to assess the efficacy of the treatments; adult mortality, oviposition, number of larvae, number of pupae and F1 progeny emergence. The findings of this experiment showed that 1.0 ml of aqueous peel extract of grape + lime had significantly higher female mortality compared to control at 3rd and 5th DAT. Aqueous peel extract of lime caused a significantly lower (70.67 + 4,3) oviposition rate compared to control (141.33+ 7.4) at 2 DAT with 1.5 ml being the most effective rate of application at 4 DAT. Aqueous peel extracts of lime was most effective in significantly reducing larval emergence (1.33 + 0.3) compared to control (8.33 + 0.5). The trend was similar for pupal emergence. Aqueous peel extracts of grape was most effective in reducing male F1 progeny emergence while lime was most effective in reducing female F1 progeny of C maculatus. Aqueous peel extract of lime could be included in control measures used by local farmers in storage of their grains for two months.

Molecular Fingerprinting and Microbiological Characterisation of Selected Vitis vinifera L. Varieties.

The aim of the study was to analyse selected aspects of the natural variability of selected varieties of Vitis vinifera. Grapevine is one of the most popular and desirable crops in the world due to the great tradition of wine production, but grape extracts also have a wide range of pharmaceutical effects on the human body. It is important to identify different varieties for the conservation of genetic resources, but also for commercial and cultivation purposes. The variability of conserved DNA-derived polymorphism profiles, as well as microbial characteristics, were analysed in this study. Six different varieties of Vitis vinifera L. were used in the study: Cabernet Savignon, Chardonney, Welschriesling, Weisser Riesling, Gewurztramines and Gruner Veltliner. Genetic polymorphism was analysed by CDDP markers for WRKY genes. Polymorphic amplicon profiles were generated by all primer combinations used in the study. Gruner Veltliner and Welschriesling were the most similar, with a similarity value at 0.778. Microbiological quality of grape and antimicrobial activity against Gram-positive and Gram-negative bacteria and yeasts were analysed further. The plate diluting method for microbial quality and the disc diffusion method for antimicrobial activity were evaluated. The number of total count of bacteria ranged between 3.12 in Cabernet Sauvignon to 3.62 log cfu/g in Grűner Veltliner. The best antimicrobial activity showed Gewurztramines against Salmonella enterica, Yersinia enterocolitica, Pseudomonas aeroginosa, Staphylococcus aureus, Listeria monocytogenes, Candida albicans, Candida krusei, and Candida tropicalis. The best antimicrobial activity was found against Enterococcus faecalis in variety Weisser Riesling.

Microencapsulated phenolic-rich extract from juice processing grape pomace (Vitis labrusca. Isabella Var): Effects on oxidative stability of raw and pre-cooked bovine burger

Grape processing generates residues rich in bioactive compounds with potential application in the meat industry. However, these substances are unstable and needs to be treated to allow their action during the processing and storage of meat products. In this sense, a phenolic-rich extract from grape pomace was microencapsulated and evaluated for its potential to inhibit the oxidative process in raw and precooked beef burgers during cold storage. Three hamburger formulations containing lyophilized extract (LEB), microencapsulated extract (MEB) and synthetic antioxidant sodium erythorbate (SEB) were prepared, pre-cooked, and evaluated for lipid and protein oxidation. The microencapsulation, with 95.0% efficiency, provided a material with a crystalline structure, rich in phenolics and with high antioxidant potential, showing 377.4 ± 0.01, 1768.1 ± 0.07 and 1185.0 ± 0.20 μmol TEAC.100 g−1 for DPPH, ABTS and FRAP, respectively. Lower values of malonaldehyde were found in LEB and MEB (2.9 ± 0.3 and 1.4 ± 0.5 mg MDA.kg−1, respectively) at the end of storage, with emphasis on for the hamburgers that received the microencapsulated extract. Similar behavior was observed for the analysis of carbonyl compounds, with values of 11.1 ± 1.1, 8.7 ± 1.4 and 6.8 ± 1.0 nM carbonyl.mg−1 in SEB, LEB and MEB, respectively. Thus, the freeze-dried and microencapsulated grape extracts showed superior results when compared to the synthetic antioxidant, increasing the oxidative stability of hamburgers, and avoiding significant color changes during the cold storage. The results indicate the high potential of the microencapsulated material to be used as a natural antioxidant in the meat industry.

Accurate varietal classification and quantification of key quality compounds of grape extracts using the absorbance-transmittance fluorescence excitation emission matrix (A-TEEM) method and machine learning

Rapid and accurate quantification of grape berry phenolics, anthocyanins and tannins and identification of grape varieties are both important for effective quality control of harvesting and initial processing for winemaking. Current reference technologies, including High-Performance Liquid Chromatography (HPLC), can be rate-limiting and too complex and expensive for effective field operations. In this paper, we analyse robotically prepared grape extracts from several key varieties (n = Calibration/n = Prediction samples), including Cabernet-Sauvignon (64/10), Grenache (16/4), Malbec (14/4), Merlot (56/10), Petite Sirah (52/10), Pinot noir (54/8), Syrah (20/2), Teroldego (14/2) and Zinfandel (62/12). Key phenolic and anthocyanin parameters measured by HPLC included Catechin, Epicatechin, Quercetin Glycosides, Malvidin 3-glucoside, Total Anthocyanins and Polymeric Tannins. Split samples diluted 50-fold in 50 % EtOH pH 2 were analysed in parallel using the A-TEEM method following Multi-block Data Fusion of the absorbance and unfolded EEM data. A-TEEM chemical data were calibrated (n = 390) using Extreme Gradient Boosting (XGB) Regression and evaluated based on the Root Mean Square Error of the Prediction (RMSEP), the Relative Error of Prediction (REP) and Coefficient of Variation (R2P) of the Prediction data (n = 62). The regression results yielded an average Relative Error of Prediction (REP) of 5.89 ± 2.47 % and an R2P of 0.941 ± 0.025. While we consider the REP values to be in the acceptable range at significantly < 10 %, we acknowledge that both the grape extraction method repeatability and HPLC reference method sample repeatability (5-8 % RSD) likely constituted the major sources of variation compared to the A-TEEM instrumental sample repeatability (< 2 % RSD). The varietal classification was analysed using Agglomerative Hierarchical Cluster Analysis (HCA) and XGB discrimination analysis of the multi-block data. The classification results yielded 100 % True Positive and True Negative responses for the Calibration and Prediction Data for all tested varieties. We conclude that the A-TEEM method requires a minimum of sample preparation and rapid acquisition times (< 1 min) and can serve as an accurate secondary method for both grape varietal identification and phenolic quantification. Importantly, the software application of the regression and classification models can be effectively automated for operators.

Ethanolic Extracts of Grape and Guava Seeds Ameliorate Gentamicin Induced Acute Renal Injury in Rats

Ethanolic Extracts of Grape and Guava Seeds Ameliorate Gentamicin Induced Acute Renal Injury in Rats

Microencapsulation of Phenolic Extract from Sea Grape (Coccoloba uvifera L.) with Antimutagenic Activity.

This study aimed to microencapsulate the sea grape ethanolic extract by the spray drying process, characterizing the obtained powder, and evaluating its antimutagenicity activity. Microparticles showed a mean size of 6.28 μm and a spherical shape with a smooth surface. The powder had a low moisture content (4.02±0.92 %) and water activity (0.27±0.01), and high solubility (76±3.60 %). Moreover, hygroscopicity (14.75±2.63 g/100 g of powder) and bulk density (0.63±0.03 g/cm3 ) values suggested that this powder can be easily handled at a pilot or industrial scale. In addition, microencapsulation protected the extract against oxidation by ultraviolet light, improved its thermal stability, and its antimutagenicity activity was similar to fresh sea grape extract. In conclusion, the microencapsulation with maltodextrin by spray drying technique is an alternative to protect bioactive compounds from sea grapes against environmental conditions, maintaining their antimutagenic activity.

Grape polyphenols decrease circulating branched chain amino acids in overfed adults.

Dietary polyphenols have long been associated with health benefits, including the prevention of obesity and related chronic diseases. Overfeeding was shown to rapidly induce weight gain and fat mass, associated with mild insulin resistance in humans, and thus represents a suitable model of the metabolic complications resulting from obesity. We studied the effects of a polyphenol-rich grape extract supplementation on the plasma metabolome during an overfeeding intervention in adults, in two randomized parallel controlled clinical trials. Blood plasma samples from 40 normal weight to overweight male adults, submitted to a 31-day overfeeding (additional 50% of energy requirement by a high calorie-high fructose diet), given either 2 g/day grape polyphenol extract or a placebo at 0, 15, 21, and 31 days were analyzed (Lyon study). Samples from a similarly designed trial on females (20 subjects) were collected in parallel (Lausanne study). Nuclear magnetic resonance (NMR)-based metabolomics was conducted to characterize metabolome changes induced by overfeeding and associated effects from polyphenol supplementation. The clinical trials are registered under the numbers NCT02145780 and NCT02225457 at ClinicalTrials.gov. Changes in plasma levels of many metabolic markers, including branched chain amino acids (BCAA), ketone bodies and glucose in both placebo as well as upon polyphenol intervention were identified in the Lyon study. Polyphenol supplementation counterbalanced levels of BCAA found to be induced by overfeeding. These results were further corroborated in the Lausanne female study. Administration of grape polyphenol-rich extract over 1 month period was associated with a protective metabolic effect against overfeeding in adults.

Recovery of antioxidant enzymes by red grape extract due to Nicotine induced changes in the liver tissue of male albino rats with reference to the aging

Recovery of antioxidant enzymes by red grape extract due to Nicotine induced changes in the liver tissue of male albino rats with reference to the aging

Evolution of the Crown Procyanidins’ Tetramer during Winemaking and Aging of Red Wine

Condensed tannins play a major role in the quality of red wine. After grape extraction, they quickly evolve thanks to different oxidation mechanisms. Recently, NMR identified a new sub class of condensed tannins, named crown procyanidins, in red wine. The crown procyanidins’ tetramer exhibits a macrocyclic structure composed of four (-)-epicatechin with an unusual cavity in the center of the molecule. These new tannins exposed a higher polarity than the linear tannins. In this work, the evolution kinetics of these crown procyanidins during the winemaking process and after aging of red wine in bottles were studied. Samples’ quantification was analyzed by UPLC-UV-Q-TOF. The concentration of cyclic and non-cyclic procyanidins was compared. During the winemaking process, crown procyanidins are mainly extracted at the beginning of the alcoholic fermentation and they remain stable until the end of the winemaking process. The high polarity and solubility of this new molecule in water was confirmed. During the aging of red wine in bottles, crown procyanidins’ concentrations are stable, whereas the non-cyclic tannins decrease dramatically. Finally, a strong oxygenation experiment confirmed the crown procyanidins’ resistance to oxidation and unique skills.

Amelioration of obesity-related metabolic disorders via supplementation of Caulerpa lentillifera in rats fed with a high-fat and high-cholesterol diet.

Dietary modification, including functional foods, could reduce comorbidities due to obesity. An increase in serum glucose and lipids is often seen in obesity. Furthermore, obesity is also characterized by a decrease in antioxidant capacity (i.e., decrease in superoxide dismutase/SOD) and downregulation of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α). It has been well established that PGC-1α is important to regulate mitochondrial biogenesis. Sea grapes (Caulerpa lentillifera) are known as a traditional food in many Asia-Pacific countries. Recent evidence suggests that sea grapes have many beneficial properties as functional foods and may have potential therapeutic functions. We investigated the effect of sea grapes (C. lentillifera) on serum glucose, lipids, PGC-1α, and protein levels of SOD in the liver of Rattus norvegicus, which is induced with a high-fat and high-cholesterol diet. A total of four groups were made, each containing ten male Rattus norvegicus; group A received a standard dry pellet diet as control, group B received cholesterol- and fat-enriched diets (CFED), groups C and D received CFED and 150 and 450 mg/kg body weight (BW) of sea grape extract, respectively, for 4 weeks. Serum glucose and cholesterol were assessed using a blood auto-analyzer. Serum PGC-1α was measured using ELISA. SOD levels were calculated using the superoxide dismutase assay kit by Sigma-Aldrich with blood taken from liver tissue. In this study, sea grape extracts improved total cholesterol levels better than the CFED and normal groups. The efficacy of total cholesterol improvement was similar between the two doses of sea grape extract. Furthermore, sea grape extract increased PCG-1α levels, especially with the dose of 150 mg/kg BW. Blood glucose was also lower in the groups of sea grape extract. Interestingly, the groups treated with sea grapes extract exhibited higher levels of liver SOD compared to the normal and CFED groups. To conclude, sea grapes (C. lentillifera) have promising potential for anti-hyperglycemia and anti-hypercholesterolemia, and for reducing oxidative stress, and providing various health benefits for metabolic disorders.

Sea Grapes Paper Towel Enriched with Activated Carbon: A Practical Innovation to Reduce Acrylamide in Fried Food

Background: One of the possible carcinogenic substances found in foods is Acrylamide (AA). This study aims to combine and innovate sea grapes (Caulerpa racemosa) extract with activated carbon into paper towels that can absorb AA levels in fried foods.
 Methods: The paper towel was created with composition of activated carbon:sea grapes extract:paper pulp using following formula: F0=0:0:100; F1=5:5:100; F2=10:5:100; F3=20:5:100. The optimal paper towel formulation was chosen based on AA reduction, fat absorption, and organoleptic properties. Data were statistically analyzed by SPSS 26.
 Results: Wrapping a fried potato using the sea grapes paper towel enriched with activated carbon for a min decreased significantly the levels of AA and oil. Although, it significantly reduced the levels of AA and percent of oil in the fried potato, but it did not change the taste and texture (p=0.566 and p=0.330). The best formulation of paper towels with composition of activated carbon, sea grapes extract, and paper pulp of 20:5:100 had the best AA level reduction, oil absorption properties, and a good taste score.
 Conclusion: This study is the first to successfully combine and innovate sea grapes extract with activated carbon as a food tissue that can reduce AA in fried foods.

Alterations in bacterial metabolites, cytokines, and mucosal integrity in the caecum of broilers caused by feed additives and host-related factors.

A total of 2,880 one-day-old male and female broiler chicks from two breeds, Ross308 and Cobb500 were randomly assigned to 72 pens. Broilers were offered three diets: a wheat-soybean diet without (CO), or with either a probiotic (probiotic; 2.4 x 109 CFU/kg diet of Bacillus subtilis DSM32324 and DSM32325 and B. amyloliquefaciens DSM25840) or a phytobiotic (phytobiotic; grape extract with 165 ppm procyanidin and 585 ppm polyphenol) product. The trial was conducted with a 3 × 2 × 2 factorial arrangement of diet, breed and sex in a completely randomized design and consisted of 6 replicate-pens per treatment (40 birds per pen). At day 7, 21, and 35, one chicken per pen was slaughtered for caecal sampling to quantify bacterial metabolites (digesta) as well as evaluate mRNA abundance and histomorphology (tissue). Data were subjected to ANOVA using GLM procedure to evaluate age, diet, breed and sex and their interactions. Spearman’s correlation (r) was analyzed between metabolite concentration and mRNA abundance. Overall, the concentration of short chain fatty acids increased with age, while lactate decreased from day 7 to 21 (p < 0.05). The mRNA abundance of IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-17α, IL-18, IFN-γ and TGF-β2 increased with age but IL-1β and TNF-α increased in abundance from day 7 to 21 and then decreased (p < 0.05). Abundance of MUC2 and CLDN5 increased after day 21 (p < 0.05). Caecal crypt depth increased with age (p < 0.05). Acidic goblet cell (GC) number peaked at day 21 (p < 0.05), while mixed GC number was not affected by age. A few impacts of breed, diet and interactions on the investigated variables showed no meaningful biological pattern. Propionate positively correlated with all cytokines investigated (r = 0.150–0.548), except TNF-α. Lactate negatively correlated with pro-inflammatory cytokines like IL-1β (r = −0.324). Aging affected caecal histomorphology, bacterial activity and genes responsible for barrier integrity and inflammatory response. This effect could be attributed to the interaction between gut microbiota and immune system as well as the direct effect of metabolites on gut histomorphology and cytokine mRNA abundance.

Preparation, physical properties, and evaluation of antioxidant capacity of aqueous grape extract loaded in chitosan-TPP nanoparticles.

Grape extract is reportedly rich in phenolic compounds that possess strong antioxidant activities. Encapsulation of such extracts in nanoparticles (NPs) is an effective way to preserve various food products. In the present study, grapes were first extracted, and the amount of total phenolic content and different types of phenolic acids was determined. The extracts at different chitosan/extract weight ratios (1:0.25, 1:0.5, 1:0.75, and 1:1) were then encapsulated in chitosan nanoparticles (NPs) using the ionic gelation method. The extract‐loaded chitosan nanoparticles were characterized by their physicochemical properties using the dynamic light scattering (DLS) technique, chemical properties using Fourier‐transform infrared (FTIR) spectroscopy, and X‐ray powder diffraction technique (XRD), the morphological properties using scanning electron microscopy (SEM), and the antioxidant activity using the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) test. The encapsulation efficiency (EE) and loading capacity (LC) were also assessed. Our findings showed that the free radical inhibition effect of NPs significantly increased with an increase in extract concentration. Chitosan NPs presented acceptable encapsulation efficiency and loading capacity (LC), and the encapsulation process enhanced the antioxidant activity of the free grape extracts. At the weight ratio of 1:0.5, the particle size and zeta potential of the NPs were 177.5 ± 2.12 nm and 32.95 ± 0.49 mV, respectively. FTIR and XRD analyses verified the credibility of the encapsulated grape extract in chitosan NPs. These NPs can be an efficient way to increase the shelf‐life of food products.