Blessings in disguise: Bio-functional benefits of grape seed extracts

Application of Modified Seed Oils of Selected Fruits in the Synthesis of Polyurethane Thermal Insulating Materials

The use of alternative raw material sources in polyurethane chemistry is necessary given the limited supply of fossil fuels, their rising prices and the concern for sustainability. The production of biopolyols from edible vegetable oils such as rapeseed oil, soybean oil or sunflower oil is often proposed. In order to avoid conflict with the global food economy, non-edible or waste oils are hoped to find application in chemical synthesis. The possibility of using oils from selected fruit seeds to obtain biopolyols is analyzed in this manuscript. Five biopolyols were obtained from watermelon, cherry, black currant, grape and pomegranate fruit seeds using the transesterification reaction of the oils with triethanolamine. Thermal insulating polyurethane foams were then obtained by replacing 75% of petrochemical polyol with the biopolyols in polyurethane systems. Based on an analysis of the foaming process, it was found that the incorporation of triethanolamine molecules into the biopolyols causes a catalytic effect. The use of such biopolyols allows eliminating the catalyst from a polyurethane foam formulation. The polyurethane biofoams obtained with the pomegranate-seed-based biopolyol were characterized by the highest content of closed cells (45 vol.%). The lowest content was found for the foams containing the currant-seed-based biopolyol (9%). The foams were characterized by thermal conductivity coefficients between 32 and 35 kW/m·K and densities of approximately 40 kg/m3. Good dimensional stability and compressive strength between 100 and 250 kPa make them suitable for use in construction.

Applications of Plant Bioactive Compounds as Replacers of Synthetic Additives in the Food Industry

According to the Codex Alimentarius, a food additive is any substance that is incorporated into a food solely for technological or organoleptic purposes during the production of that food. Food additives can be of synthetic or natural origin. Several scientific evidence (in vitro studies and epidemiological studies like the controversial Southampton study published in 2007) have pointed out that several synthetic additives may lead to health issues for consumers. In that sense, the actual consumer searches for "Clean Label" foods with ingredient lists clean of coded additives, which are rejected by the actual consumer, highlighting the need to distinguish synthetic and natural codded additives from the ingredient lists. However, this natural approach must focus on an integrated vision of the replacement of chemical substances from the food ingredients, food contact materials (packaging), and their application on the final product. Hence, natural plant alternatives are hereby presented, analyzing their potential success in replacing common synthetic emulsifiers, colorants, flavorings, inhibitors of quality-degrading enzymes, antimicrobials, and antioxidants. In addition, the need for a complete absence of chemical additive migration to the food is approached through the use of plant-origin bioactive compounds (e.g., plant essential oils) incorporated in active packaging.

Effects of diets containing grape pomace on the growth, nutrition indices, and the quality traits of common carp (Cyprinus carpio)

The fish diet is one of the essential factors in the development of aquaculture. The purpose of present study was to evaluate using grape pomace as a main feed ingredient on growth performance, body chemical composition, survival rate, and morphological indices of the carp (Cyprinus carpio). 200 fish with an average weight of 7 ± 0.4 g were randomly distributed in four tanks for total of 56 days. The fish were fed with a diet containing 5%, 10%, and 15% grape pomace in different feeding groups designated as G1, G2, and G3. The average daily weight gain (g), weights gain (g), and specific growth rate (%) were significantly higher (p < .05) in G3 as compared to G1 and G2 groups. The lowest feed conversion ratio was recorded in G3 group. The morphological indices, condition factors, viscerosomatic index, and hepatosomatic index were significantly higher in G3 group as compared to other treatments. The protein, fat, moisture, and ash contents in the C. carpio fillets were significantly influenced by feeding rate. The results showed that grape pomace had a positive effect on growth, survival, and nutritional indices in the carp fish. According to the obtained results, grape pomace (150 g/kg food) can be considered as the diet component for the carp fish.

The natural tannins oligomeric proanthocyanidins and punicalagin are potent inhibitors of infection by SARS-CoV-2

The Coronavirus Disease 2019 (COVID-19) pandemic continues to infect people worldwide. While the vaccinated population has been increasing, the rising breakthrough infection persists in the vaccinated population. For living with the virus, the dietary guidelines to prevent virus infection are worthy of and timely to develop further. Tannic acid has been demonstrated to be an effective inhibitor of coronavirus and is under clinical trial. Here we found that two other members of the tannins family, oligomeric proanthocyanidins (OPCs) and punicalagin, are also potent inhibitors against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with different mechanisms. OPCs and punicalagin showed inhibitory activity against omicron variants of SARS-CoV-2 infection. The water extractant of the grape seed was rich in OPCs and also exhibited the strongest inhibitory activities for viral entry of wild-type and other variants in vitro. Moreover, we evaluated the inhibitory activity of grape seed extractants (GSE) supplementation against SARS-CoV-2 viral entry in vivo and observed that serum samples from the healthy human subjects had suppressive activity against different variants of SARS-CoV-2 Vpp infection after taking GSE capsules. Our results suggest that natural tannins acted as potent inhibitors against SARS-CoV-2 infection, and GSE supplementation could serve as healthy food for infection prevention.

Comparing the Effects of Concord Grape (Vitis labrusca L.) Puree, Juice, and Pomace on Intestinal Morphology, Functionality, and Bacterial Populations In Vivo (Gallus gallus)

This is a preliminary study evaluating the effect of different fractions of Concord grapes (Vitis labrusca L.) on the brush border membrane (BBM) morphology, duodenal gene expression, and specific gut bacterial populations. For this study, we utilized a unique intraamniotic approach, wherein, the test substances are administered into the amnion of the Gallus gallus egg (on day 17). The embryo orally consumes the amniotic fluid along with the injected test substance before the hatch. We randomly divided ~50 fertilized eggs into 5 groups including 6% grape (juice, puree, and pomace) along with controls (no injection and diluent—H2O). The grape juice was prepared by crushing the grapes; the grape residues were used as pomace. The grape puree included the grape skin, endocarp, mesocarp, and juice but not the seeds. On day 21, the hatch day, the blood, pectoral muscle, liver, duodenum, and large intestine were harvested. Our results showed no significant differences in blood glucose, pectoral glycogen level, or body weight. However, significant (p < 0.05) differences in duodenal and liver gene expression were observed between the treatment groups. The grape puree treatment resulted in higher Clostridium numbers and lower Bifidobacterium numbers when compared to all other groups. In summary, the dietary consumption of grape polyphenols has the potential to beneficially modulate aspects of intestinal health provided their concentration is limited.

Enzymatic pre-treatment of grape seeds for an oil with higher antioxidant activity

The paper investigates the effect of the enzymatic pre-treatment of grape seeds from six Romanian cultivars on the oil extracted. The grape seeds of some white and red Romanian grape varieties were separated from winery waste, washed, dried and ground, with the oil then obtained by extraction with petroleum ether. The extraction was performed directly or after a preliminary treatment with a commercial pectin lyase. The enzymatic procedure applied was more cost effective compared to other treatments previously described in which a cocktail of enzymes was used. The quantity of the extracted oil was measured in both types of processing, with an increase being observed for pre-treated samples. The fatty acid profiles (FAPs) of the oils resulted for the treated and untreated seeds were determined. No change in the composition was noticed. The reductive power of these oils was also investigated. Compared to the untreated samples for the same variety, the enzyme pre-treatment resulted in a superior antioxidant capacity.

The effect of grape seed extract supplementation on oxidative stress and inflammation: A systematic review and meta-analysis of controlled trials

BACKGROUND

Grape seed extract (GSE) seems to have antioxidant and anti-inflammatory properties due to its high polyphenolic content. Nevertheless, the scientific literature in this field is controversial and inconclusive. Therefore, we aimed to conduct a systematic review and meta-analysis of controlled trials to evaluate the effect of supplementation with GSE on biomarkers of oxidative stress and inflammation.

METHODS

Medline, Scopus, Cochrane Library, Google Scholar and Web of Science databases were searched up to 10 September 2020 using appropriate keywords without restrictions. In the systematic review phase, all biomarkers of oxidative stress and inflammation were considered as outcomes. In the meta-analysis phase, six biomarkers were selected as outcomes, and weighted mean difference (WMD) or standardised mean difference (SMD) with 95% confidence interval (CI) was calculated for them using a random-effects model.

RESULTS

Twenty-three studies were included in the systematic review, and 19 studies were included in the meta-analysis. GSE supplementation caused a significant decrease in malondialdehyde (SMD: -1.04, 95% CI: -1.65, -0.42), oxidised low-density lipoprotein (SMD: -0.44, 95% CI: -0.75, -0.13) and high-sensitivity C-reactive protein (WMD: -0.48 mg/L, 95% CI: -0.94, -0.03) and a marginally significant increase in total antioxidant capacity (SMD: 0.49, 95% CI: -0.05, 1.04) but did not significantly influence C-reactive protein (WMD: -0.36 mg/L, 95% CI: -1.02, 0.30) and white blood cell count (WMD: 0.12 × 10⁹ /L, 95% CI: -0.25, 0.48).

CONCLUSION

It appears that GSE supplementation can remarkably modulate the body's redox system, particularly through the inhibition of lipid peroxidation, but has neutral or mildly beneficial effects on inflammatory responses.

Antioxidant and polyphenol content of different Vitis vinifera seed cultivars and two facilities of production of a functional bakery product

This study aimed to examine the differences between the antioxidant capacity, and the total polyphenol content of the seed of eight different grape varieties. We also attempt to create a functional loaf enriched with grape seed meal. To achieve this goal, 3, 6, and 9% of the grape seed meal were added to the loaves made of bread flour and gluten-free flour mixture, and then the changes in their antioxidant and polyphenol content were examined. Based on the results, there were significant differences between the polyphenol and antioxidant content of grape seed varieties. The antioxidant content of the grape seeds varied between 228.50 mg AAE/g (94.80 mg TE/g) and 438.33 mg AAE/g (181.86 mg TE/g) in case of fatty samples, and between 176.29 mg AAE/g (41.24 mg TE/g) and 424.91 mg AAE/g (99.40 mg TE/g) in case of defatted samples. The total polyphenol content of the fatty samples changed between 91.16 and 221.81 mg GAE/g; in case of defatted samples, it ranged from 46.01 to 207.68 mg GAE/g. Rhine Riesling contained the greatest amount of these compounds. The functionality of loafs was confirmed by spectrophotometric analysis. Total polyphenol content ranged from 0.91 to 3.16 mg GAE/g in case of wheat loafs, and from 1.39 to 5.92 mg GAE/g in case of gluten-free loafs, while the total antioxidant content changed between 0.70 and 6.44 mg AAE/g in case of wheat loafs, and ranged from 2.55 to 9.75 in case of gluten-free loafs.

GRAPHIC ABSTRACT

Changes in rainbow trout (Oncorhynchus mykiss) growth and mucosal immune parameters after dietary administration of grape (Vitis vinifera) seed extract

The effect of dietary grape (Vitis vinifera) seed extract (GSE) on growth performance and mucosal immune parameters in rainbow trout (Oncorhynchus mykiss) fry was studied. Fish (1.3 g mean weight) were randomly distributed in nine tanks (15 fish per tank) and fed diets containing GSE at 0 (control), 100, and 200 mg kg^-1for 60 days. The results showed that growth parameters were enhanced in both treatment groups compared to the control group. Histological examination of fish skin showed higher epidermis thickness, goblet cell density, and volume density in the GSE groups compared to the values of the control group. Furthermore, the villus height, goblet cell density, and intraepithelial lymphocytes were increased in the fish intestine in those fish fed GSE, with respect to control fish. Feeding fish with low dose of GSE (100 mg kg^-1) up-regulated the expression of some immune-relevant genes, including complement component 3 (C3), lysozyme (Lys), omDB-3, interferon gamma (IFN-γ), and tumor necrosis factor-α (TNF-α) in different mucosal tissues. However, feeding fish the high dose of GSE (200 mg kg^-1) mostly enhanced expression of these genes in the skin. Besides, skin mucus of fish fed GSE showed bactericidal activity against Yersinia ruckeri. It was concluded that GSE, especially at 100 mg kg^-1, modulates the growth performance and mucosal immunity of rainbow trout.

Extract of grape seed enhances the growth performance, humoral and mucosal immunity, and resistance of common carp (Cyprinus carpio) against Aeromonas hydrophila

This study evaluated the effects of grape seed extract (GSE) on the growth performance, immune response, and disease resistance of common carp (Cyprinus carpio). Fish were distributed in four groups and fed diets with varying levels of GSE at 0, 10, 20, and 30 g/kg for 56 days. The final length in fish fed with 20 and 30 g GSE/kg diet significantly increased in comparison with the control group (P<0.05). The final weight and weight gain of fish fed with GSE were statistically higher than for the control diet, while the feed conversion ratio was lower in GSE groups than the control. Hematological parameters did not statistically improve with GSE supplemented diets (P>0.05). However, fish fed with 30 g GSE/kg diet displayed a significantly higher WBC count than the other group (P<0.05). The serum total protein and globulin in fish fed with 20 g GSE/kg diet significantly increased compared to the control (P<0.05). A similar pattern was noticed in results for serum and mucus lysozyme activity with a significant increase in fish fed with 20 and 30 g GSE/kg diet compared to the control (P<0.05). Total antibody levels in serum and mucus samples were also increased in fish by dietary GSE with maximum levels by 20 and 30 g GSE/kg diet. Besides, mucus protease activity was higher in fish that received 20 and 30 g GSE/kg diet with maximum level shown in fish fed with 30 g GSE/kg diet compared to the control group (P<0.05). Meanwhile, all groups showed higher mucus antibacterial activity against Aeromonas hydrophila with the highest activity in 30 g GSE/kg diet in comparison with the control group. The cumulative mortality was 36.67% when fish were fed with 30 g GSE/kg diet and challenged with A. hydrophila. However, the mortality rate was 40% and 53.33% in fish fed 20 and 30 g GSE/kg diet, respectively. This study suggests that supplementation of GSE could significantly enhance the growth performance, immune responses, and disease resistance against A. hydrophila in common carp.

Air frying combined with grape seed extract inhibits Nε-carboxymethyllysine and Nε-carboxyethyllysine by controlling oxidation and glycosylation

Advanced glycation end products (AGE), compounds formed in meat at the advanced stage of Maillard reaction, are easily exposed to thermal processing. Improving cooking condition and adding antioxidants are 2 common ways for AGE reduction. The present work compared the inhibition of grape seed extract (GSE) on levels of free and protein-bound N^ε-carboxymethyllysine (CML) and N^ε-carboxyethyllysine (CEL) in chicken breast under deep-frying and air-frying conditions. Efficiency of 5 concentrations of GSE (0.0, 0.2, 0.5, 0.8, and 1.0 g/kg) in retarding oxidation, glyoxal (GO), methylglyoxal (MGO), lysine (Lys), Maillard reaction degree (A₂₉₄, A₄₂₀), and Shiff's base were tested. Results showed that 0.5 g/kg GSE before heating significantly (P < 0.05) reduced AGE in fried breast chicken, whereas excessive supplementation of GSE (0.8 and 1 g/kg) was reverse. Air frying was found significantly (P < 0.05) better than deep frying to reduce the precursor substances (GO, MGO, and Lys) of AGE. In conclusion, GSE-derived polyphenols exhibited different inhibitory effects on oxidation and glycosylation at different concentrations. We found that 0.5 g/kg of GSE combined with air frying was the best recommendation for inhibiting CML and CEL.

Administration of grape (Vitis vinifera) seed extract to rainbow trout (Oncorhynchus mykiss) modulates growth performance, some biochemical parameters, and antioxidant-relevant gene expression

Grape seed, as a main source of polyphenols, has many nutritional and medicinal properties in humans. In the current study, the effects of dietary ethanolic grape seed extract (GSE) on the growth performance, antioxidant activity, and some biochemical parameters in rainbow trout were investigated. Ninety fish (initial weight 78.47 g) were randomly distributed among nine cement tanks (1.8 m × 0.22 m × 0.35 m) with 10 fish per tank. Three experimental diets containing either 0, 10, or 50 g kg^-1 GSE were prepared and each diet was randomly assigned to three tanks of fish for 60 days. Results showed that feeding GSE enhanced some growth parameters including the specific growth rate and condition factor in comparison with the control group. Among different serum metabolites, the glucose levels in treatment groups significantly decreased compared to the control group. The total product of lipid peroxidation indicated as malondialdehyde significantly decreased in both the GSE-added treatment groups. The gene expression related to the antioxidant enzymes, catalase, glutathione peroxidase 1, and glutathione S-transferase A, were upregulated in the intestine of fish that received a low dose of GSE. The results of the current study suggest that GSE, especially at 10 g kg^-1, diet had the potential to improve (1) specific growth rate and condition factor, (2) biochemical parameters including glucose and lipid peroxidation product, and (3) upregulated the expression of antioxidant genes including catalase, glutathione peroxidase 1, and glutathione S-transferase A in rainbow trout.

Fruits By-Products - A Source of Valuable Active Principles. A Short Review

The growing demand for more sustainable, alternative processes leading to production of plant-derived preparations imposes the use of plants waste generated mainly by agri-food and pharmaceutical industries. These mostly unexploited but large quantities of plants waste also increase the interest in developing alternative approaches for sustainable production of therapeutic molecules. In order to reduce the amount of plant waste by further processing, different novel extraction techniques can be applied. Fruits and their industrial by-products are rich sources of different classes of compounds with therapeutic properties. The processed fruits waste can be reused and lead to novel pharmaceuticals, food supplements or functional foods. This review intends to briefly summarize recent aspects regarding the production of different active compounds from fruit by-products, and their therapeutic properties. The potential use of fruits by-products in different industries will be also discussed.

Effect of natural extracts obtained from food industry by-products on nutritional quality and shelf life of chicken nuggets enriched with organic Zn and Se provided in broiler diet

This study investigated the influence of an organic mineral-supplemented broiler diet on the quality of nuggets. The resulting chicken nuggets were enriched with inorganic and organic forms of Zn and Se. The nuggets were processed by incorporating extracts from food industry by-products (rosemary [R_H and R_L], hydroxytyrosol [HYT], pomegranate [P], grape [GS], and Harpagophytum [H]). The physiochemical, microbiological, and sensory characteristics of the chicken nuggets were evaluated over a 12-month period of frozen storage. The addition of natural extracts did not affect the pH, proximate composition, or color (CIELab) of the nuggets among samples. However, significative differences were found between month of analysis (range from pH 6.16 to 6.63; luminosity from 62.51 to 84.74; redness from 0.16 to 7.14; and yellowness from 10.80 to 33.77). In addition, the combination of phenolic compounds with Zn and Se retarded microbial growth and reduced protein and lipid oxidation, thus maintaining the sensory quality and extending the shelf life of this product. For instance, the combination of R_L + GS reduced in 75% the microbiological growth regarding the control sample (C), while samples that incorporated R_H + P or HYT + P + H presented 50% less than C. In addition, upon only incorporating organic minerals Zn and Se, microbiological deterioration is reduced in 15%. This mix was significantly effective at reducing the oxidative reactions of lipids and proteins by 40% and 50%, as measured after 9 and 12 mo of frozen storage, respectively. The addition of the natural extracts and Zn and Se did not adversely affect the acceptability of the meat product.

Molecular hybridization of grape seed extract: Synthesis, structural characterization and anti-proliferative activity in vitro

The grape seed extract (GSE) hybridized with medium-chain saturated fatty acids (decanoic acid) exhibited higher lipophilicity, antioxidant activity, and anti-proliferative activity than its parents. The chemical structures of individual hybridized GSE derivatives were identified as 3'-O-decanoyl catechin, 3'-O-decanoyl epicatechin, 3', 5'-2-O-decanoyl epigallocatechin, and 3', 4', 3″, 5″-4-O-decanoyl epicatechin gallate by HPLC-MS² and ¹H and ¹³C NMR. For growth inhibitory effect on HepG2 cells, hybridized GSE derivatives (EC₅₀ = 44.38 μg/mL) were significantly (p < 0.01) stronger than natural GSE (EC₅₀ = 60.83 μg/mL) due to increased lipophilicity. The effects of GSE derivatives on apoptosis and cell cycle in HepG2 cells were further evaluated by flow cytometry. The results showed that the percentage of apoptotic cells increased markedly in the presence of hybridized GSE derivatives. Moreover, hybridized GSE derivatives were capable of inducing cell cycle arrest in G1 phase. This research suggests that hybridized GSE derivatives are effective lipophilic antioxidants and show the potential as adjuvant therapy for cancer.

Preparation and Characterisation of Polyphenol-HP-β-Cyclodextrin Inclusion Complex that Protects Lamb Tripe Protein against Oxidation

Grape seed extract (GSE) displays strong antioxidant activity, but its instability creates barriers to its applications. Herein, three HP-β-CD/GSE inclusion complexes with host-guest ratios of 1:0.5, 1:1, and 1:2 were successfully prepared by co-precipitation method to improve stability. Successful embedding of GSE in the HP-β-CD cavity was confirmed by fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) analyses. The Autodock Tools 1.5.6 was used to simulate the three-dimensional supramolecular structure of the inclusion complex of 2-hydroxypropyl-β-cyclodextrin and grape seed extract (HP-β-CD/GSE) by molecular docking. The MALDI-TOF-MS technology and chemical database Pubchem, and structural database PDB were combined to reconstitute the three-dimensional structure of target protein. The binding mode of the HP-β-CD/GSE inclusion complex to target protein was studied at the molecular level, and the antioxidant ability of the resulting HP-β-CD/GSE inclusion complexes was investigated by measuring 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging. The effects of HP-β-CD/GSE on myofibrillar protein from lamb tripe were also investigated under oxidative conditions. The positions and interactions of the binding sites of HP-β-CD/GSE inclusion complexes and target protein receptors were simulated by molecular docking. The results showed that HP-β-CD/GSE inclusion complexes were successfully prepared, optimally at a molar ratio of 1:2. At low (5 μmol/g) to medium (105 μmol/g) concentrations, HP-β-CD/GSE inclusion complexes decreased the carbonyl content, hydrophobicity, and protein aggregation of myofibrillar protein from lamb tripe, and increased the sulphydryl content. Furthermore, high concentration (155 μmol/g) of HP-β-CD/GSE inclusion complexes promoted protein oxidation.

Valorization of underutilized North American pawpaw (Asimina triloba): investigation as a lipid oxidation inhibitor in turkey homogenate model system

BACKGROUND

The objective of this study was to characterize the ability of extracts from nine varieties of pawpaw pulp standardized to the phenolics level of 0.1% grape seed extract (GSE) on inhibition of the formation of thiobarbituric reactive substances (TBARS) in a turkey model system. The antioxidant activity of the extracts was also determined using four common assays.

RESULTS

Over the 240 min sampling time, the standardized pawpaw extracts from all nine varieties were as effective as GSE in inhibiting TBARS formation in turkey muscle homogenate compared to the untreated control. Extracts from all pawpaw varieties and GSE began to inhibit TBARS formation at 60 min of incubation, and by 240 min TBARS were reduced from 35 μmol malondialdehyde kg^-1 tissue in the homogenate to which no antioxidant was added to 4-18 μmol malondialdehyde kg^-1 tissue in the antioxidant-enriched extracts. There does not appear to be a clear relationship between inhibition of TBARS and any of the antioxidant capacity measurements (ORAC, DPPH inhibition, reducing potential as measured by FRAP assay, or pyrogallol red bleaching).

CONCLUSION

The results of this research indicate that there is potential to add value to pawpaw as a functional food source of natural antioxidants, particularly in meat products. © 2017 Society of Chemical Industry.