Merlot grape pomace hydroalcoholic extract improves the oxidative and inflammatory states of rats with adjuvant-induced arthritis

Grape Pomace Polyphenols Reduce Acute Inflammatory Response Induced by Carrageenan in a Murine Model

Grape pomace (GP), a by-product of wine production, contains bioactive polyphenols with potential health benefits. This study investigates the anti-inflammatory properties of a polyphenolic fraction derived from GP, obtained by ultrasound-microwave hybrid extraction and purified using ion-exchange chromatography. In the inflammation model, mice were divided into six groups: intact, carrageenan, indomethacin, and three GP polyphenols treatment groups. Paw edema was induced by subplantar injection of carrageenan, and the GP polyphenols were administered intraperitoneally at doses of 10, 20, and 40 mg/kg. The anti-inflammatory effect was evaluated by measuring paw volume, and expression of inflammatory markers: cyclooxygenase-2 (COX-2), myeloperoxidase (MPO), and cytokines (IL-1β and IL-6), along with lipid peroxidation levels. The GP polyphenols significantly reduced paw edema and expression levels of COX-2, MPO, and cytokines in a dose-dependent manner effect, with the highest dose showing the greatest reduction. Additionally, lipid peroxidation levels were also decreased by GP polyphenols treatment at doses of 10 and 20 mg/kg. These findings suggest that ultrasound-microwave extraction combined with amberlite purification proved to be effective in obtaining a polyphenolic-rich fraction from GP. Thus, GP polyphenols may serve as a natural anti-inflammatory and antioxidant agent for treating inflammation and oxidative stress-related diseases.

Absorbent bioactive aerogels based on germinated wheat starch and grape skin extract

This study aimed to produce water-absorbent bioactive aerogels using biodegradable raw materials, wheat starch and poly ethylene oxide (PEO), and derived from agro-industrial residues (grape skin) obtained in the wine industry. The aerogels were produced using germinated wheat starch (GWS), with and without PEO, and incorporating grape skin extract (GSE) at concentrations of 5 and 10 % (w/w). The GSE was evaluated for total and individual phenolic compounds, anthocyanins, and antioxidant activity. The starch aerogels were characterized for morphology, density, porosity, functional groups by FT-IR, relative crystallinity and diffraction pattern, water absorption capacity, antioxidant activity, and in vitro release profile of phenolic compounds in food simulant medium. The total phenolic compounds in GSE was 226.25 ± 0.01 mg equivalent of gallic acid/g GSE. The aerogels showed low density and high porosity. All aerogels demonstrated high water absorption capacity (581.4 to 997.5 %). The antioxidant activity of the aerogels increased with increasing GSE concentration and the addition of PEO. The aerogels could release GSE gradually for up to 120 days in the hydrophilic simulant medium and 240 h for the hydrophobic medium. Starch-based aerogels with GSE showed potential to be applied as exudate absorbers with antioxidant activity to develop active food packaging.

Nutraceuticals as Modulators of Immune Function: A Review of Potential Therapeutic Effects

Dietary supplementation with nutraceuticals can promote optimal immune system activation, modulating different pathways that enhance immune defenses. Therefore, the immunity-boosting effects of nutraceuticals encompass not only immunomodulatory but also antioxidant, antitumor, antiviral, antibacterial, and antifungal properties, with therapeutic effects against diverse pathological conditions. However, the complexity of the pathways that regulate the immune system, numerous mechanisms of action, and heterogeneity of the immunodeficiencies, and subjects treated make their application in the clinical field difficult. Some nutraceuticals appear to safely improve immune system function, particularly by preventing viral and bacterial infections in specific groups, such as children, the elderly, and athletes, as well as in frail patients, such as those affected by autoimmune diseases, chronic diseases, or cancer. Several nutraceuticals, such as vitamins, mineral salts, polyunsaturated omega-3 fatty acids, many types of phytocompounds, and probiotic strains, have the most consolidated evidence in humans. In most cases, further large and long-term randomized clinical trials are needed to confirm the available preliminary positive data.

Brazilian berry waste as a source of bioactive compounds: grumixama (Eugenia brasiliensis Lam.) as a case study

Grumixama, Eugenia brasiliensis Lam., is a Brazilian berry little explored commercially and scientifically. However, local small producers market this fruit in the form of frozen pulp, which generates bioresidues, composed of seeds and peels. With the view to propose strategies for valuing grumixama, this study aimed to determine the chemical composition and assess the bioactivities of the hydroethanolic extracts of the whole residue (GR), seed (GS) and peel (GP) fractions of E. brasiliensis. From the results, GP had the highest concentration of organic acids (oxalic, malic, ascorbic and citric acids), total tocopherols, condensed tannins, anthocyanins, and other flavonoids. On the other hand, GS showed the highest content of monounsaturated fatty acids and hydrolysable tannins, whereas GR displayed a mixture of compounds detected in each of its parts. Regarding the bioactivities, low extract concentrations were required in two in vitro antioxidant assays, namely TBARS (EC₅₀ = 0.90-1.34 μg mL^-1) and OxHLIA (IC₅₀ = 21-65 μg mL^-1). Furthermore, GP had the highest inhibition activity of cellular oxidation in the CAA assay (80 ± 0.6%), while GS showed the highest anti-inflammatory activity via nitric oxide production inhibition (EC₅₀ = 98.0 ± 0.5 μg mL^-1). All samples induced cell growth inhibition of the tested tumor cells (GI₅₀ = 14.7-186 μg mL^-1) besides antibacterial and antifungal effects at low concentrations, but all samples were harmful to normal cells at moderate concentrations (GI₅₀ = 145-268 μg mL^-1). Therefore, E. brasiliensis residue could be a good source of bioactive compounds to be used in several areas. However, additional studies are needed to confirm its safety as well as to unravel the mechanisms behind its biological activities.

Valorization of rambutan (Nephelium lappaceum L.) peel: Chemical composition, biological activity, and optimized recovery of anthocyanins

Chemical constituents and bioactive properties of rambutan (Nephelium lappaceum L.) peel were characterized and heat-/ultrasound-assisted extractions (HAE/UAE) of anthocyanins were optimized by response surface methodology. Five organic acids, the α-, γ-, and δ-tocopherol isoforms, and twenty-five fatty acids (36.8 % oleic acid) were identified, as well as a phenolic profile composed of ellagitannin derivatives, geraniin isomers, ellagic acid, and delphinidin-O derivatives. The extract showed antioxidant activity via lipid peroxidation (IC₅₀ = 2.79 ± 0.03 µg/mL) and oxidative hemolysis (IC₅₀ = 72 ± 2 µg/mL) inhibition, and displayed antibacterial and antifungal properties (MIC ≤ 1 mg/mL). On the other hand, no cytotoxicity was observed in tumor and non-tumor cell lines up to 400 µg/mL. The recovery of anthocyanins was more effective using HAE than UAE, allowing greater yields (16.2 mg/g extract) in just 3 min and using lower ethanol proportions. Overall, rambutan peel could be upcycled into bioactive ingredients and natural colorants for industrial applications.

Insights into the Chemical Composition and In Vitro Bioactive Properties of Mangosteen (Garcinia mangostana L.) Pericarp

The industrial processing of mangosteen (Garcinia mangostana L.) generates high amounts of waste, as ~60% of the fruit is formed by an inedible pericarp. However, its pericarp has been explored as a source of xanthones; nevertheless, studies addressing the recovery of other chemical compounds from such biomass are still scarce. Hence, this study intended to elucidate the chemical composition of the mangosteen pericarp, including fat-soluble (tocopherols and fatty acids) and water-soluble (organic acids and phenolic compound non-xanthones) compounds present in the following extracts: hydroethanolic (MT80), ethanolic (MTE), and aqueous (MTW). In addition, the antioxidant, anti-inflammatory, antiproliferative and antibacterial potentials of the extracts were assessed. The mangosteen pericarp showed a composition with seven organic acids, three tocopherol isomers, four fatty acids and fifteen phenolic compounds. Regarding the extraction of phenolics, the MT80 was the most efficient (54 mg/g extract), followed by MTE (19.79 mg/g extract) and MTW (4.011 mg/g extract). All extracts showed antioxidant and antibacterial activities; however, MT80 and MTE extracts were more efficient than MTW. Only MTW did not show anti-inflammatory properties, whereas MTE and MT80 showed inhibitory activities towards tumor cell lines. Notwithstanding, MTE showed cytotoxicity towards normal cells. Our findings support the idea that the ripe mangosteen pericarp is a source of bioactive compounds, although their recovery is dependent on the extraction solvent.

Phytochemicals Recovery from Grape Pomace: Extraction Improvement and Chemometric Study

In the last 20 years, an increased interest has been shown in the application of different types and combinations of enzymes to obtain phenolic extracts from grape pomace in order to maximize its valorization. Within this framework, the present study aims at improving the recovery of phenolic compounds from Merlot and Garganega pomace and at contributing to the scientific background of enzyme-assisted extraction. Five commercial cellulolytic enzymes were tested in different conditions. Phenolic compound extraction yields were analyzed via a Design of Experiments (DoE) methodology and a second extraction step with acetone was sequentially added. According to DoE, 2% w/w enzyme/substrate ratio was more effective than 1%, allowing a higher total phenol recovery, while the effect of incubation time (2 or 4 h) variation was more enzyme-dependent. Extracts were characterized via spectrophotometric and HPLC-DAD analyses. The results proved that enzymatic and acetone Merlot and Garganega pomace extracts were complex mixtures of compounds. The use of different cellulolytic enzymes led to different extract compositions, as demonstrated using PCA models. The enzyme effects were observed both in water enzymatic and in the subsequent acetone extracts, probably due to their specific grape cell wall degradation and leading to the recovery of different molecule arrays.

Purple tea: chemical characterization and evaluation as inhibitor of pancreatic lipase and fat digestion in mice

A variety of the classic green tea plant, Camellia sinensis, was developed and is exclusive to Kenya. Due to high content of anthocyanin polyphenols in its leaves, the beverage obtained from this variety is purple in color and is the origin of the name purple tea. This work had two main purposes. The first one was to identify and quantify the major anthocyanin polyphenols in a hot water aqueous extract of the purple tea leaves. The second one was to test the hypothesis if this extract is capable of inhibiting triglyceride absorption considering that anthocyanin polyphenolics have been frequently associated to antilipidemic effects. Parallel experiments were always done with a similar green tea extract for comparison purposes. The antioxidant, anti-inflammatory, and cytotoxic activities of both tea varieties are similar. The purple tea extract, however, was strongly inhibitory toward the pancreatic lipase (minimal IC₅₀ = 67.4 μg mL^-1), whereas the green tea preparation was a weak inhibitor. Triglyceride digestion in mice was inhibited by the purple tea extract starting at 100 mg kg^-1 dose and with a well-defined dose dependence. Green tea had no effect on triglyceride digestion at doses up to 500 mg kg^-1. The latter effect is probably caused by several components in the purple tea extract including non-anthocyanin and anthocyanin polyphenols, the first ones acting solely via the inhibition of the pancreatic lipase and the latter by inhibiting both the lipase and the transport of free fatty acids from the intestinal lumen into the circulating blood. The results suggest that the regular consumption of Kenyan purple tea can be useful in the control of obesity.

Phytochemicals Derived from Agricultural Residues and Their Valuable Properties and Applications

Billions of tons of agro-industrial residues are produced worldwide. This is associated with the risk of pollution as well as management and economic problems. Simultaneously, non-edible portions of many crops are rich in bioactive compounds with valuable properties. For this reason, developing various methods for utilizing agro-industrial residues as a source of high-value by-products is very important. The main objective of the paper is a review of the newest studies on biologically active compounds included in non-edible parts of crops with the highest amount of waste generated annually in the world. The review also provides the newest data on the chemical and biological properties, as well as the potential application of phytochemicals from such waste. The review shows that, in 2020, there were above 6 billion tonnes of residues only from the most popular crops. The greatest amount is generated during sugar, oil, and flour production. All described residues contain valuable phytochemicals that exhibit antioxidant, antimicrobial and very often anti-cancer activity. Many studies show interesting applications, mainly in pharmaceuticals and food production, but also in agriculture and wastewater remediation, as well as metal and steel industries.

The α-Amylase and α-Glucosidase Inhibition Capacity of Grape Pomace: A Review

The concept of functional foods is gaining more importance due to its role in maintaining a healthy status and preventing some metabolic diseases. The control of diabetes, in particular type-2 (T2DM), could be considered a big challenge since it involves other factors such as eating habits. From the pharmacological point of view, inhibiting digestive enzymes, such as α-amylase and α-glucosidase, is one of the mechanisms mainly used by synthetic drugs to control this disease; however, several side effects are described. For that reason, using bioactive compounds may appear as an alternative without presenting the complications synthetic drugs available on the market have. The winemaking industry generates tons of waste annually, and grape pomace (GP) is the most important. GP is recognized for its nutritional value and as a source of bioactive compounds that are helpful for human health. This review highlights the importance of GP as a possible source of α-amylase and α-glucosidase inhibitors. Also, it is emphasized the components involved in this bioactivity and the possible interactions among them. Especially, some phenolic compounds and fiber of GP are the main ones responsible for interfering with the human digestive enzymes. Preliminary studies in vitro confirmed this bioactivity; however, further information is required to allow the specific use of GP as a functional ingredient inside the market of products recommended for people with diabetes.

Graphical abstract

A Critical Appraisal of the Most Recent Investigations on the Hepatoprotective Action of Brazilian Plants

Conventional treatments for liver diseases are often burdened by side effects caused by chemicals. For minimizing this problem, the search for medicines based on natural products has increased. The objective of this review was to collect data on the potential hepatoprotective activity of plants of the Brazilian native flora. Special attention was given to the modes of extraction, activity indicators, and identification of the active compounds. The databases were Science direct, Pubmed, and Google Academic. Inclusion criteria were: (a) plants native to Brazil; (b) studies carried out during the last 15 years; (c) high-quality research. A fair number of communications met these criteria. Various parts of plants can be used, e.g., fruit peels, seeds, stem barks, and leaves. An outstanding characteristic of the active extracts is that they were mostly obtained from plant parts with low commercial potential, i.e., by-products or bio-residues. The hepatoprotective activities are exerted by constituents such as flavonoids, phenolic acids, vitamin C, phytosterols, and fructose poly- and oligosaccharides. Several Brazilian plants present excellent perspectives for the obtainment of hepatoprotective formulations. Very important is the economical perspective for the rural producers which may eventually increase their revenue by selling increasingly valued raw materials which otherwise would be wasted.

Pineapple by-products as a source of bioactive compounds with potential for industrial food application

Pineapple is a tropical fruit consumed fresh or processed into various food products. However, the peel and crown of this fruit are not industrially exploited, thus generating tons of by-products that represent an economic and environmental concern. In order to promote the upcycling of these by-products, this work aimed to characterize the phenolic profile of its hydroethanolic extracts obtained from pineapple peel and crown leaves and to evaluate their in vitro bioactivity. The HPLC-DAD-ESI/MS analysis allowed the identification of 25 phenolic compounds, including phenolic acids and flavonoids. The antioxidant, cytotoxic, and antimicrobial activity assays highlighted the peel extract as the most promising and, therefore, it was incorporated into a traditional Portuguese pastry cake as a functional ingredient. The nutritional parameters of the developed food were not affected by the incorporation of the extract, but it promoted the antioxidant activity during its shelf-life. Overall, pineapple peel and crown appeared as promising by-products to be exploited by the food industry, which can be achieved through a circular economy approach.

Food Industry Byproducts as Starting Material for Innovative, Green Feed Formulation: A Sustainable Alternative for Poultry Feeding

Rising global populations and enhanced standards of living in so-called developing countries have led to an increased demand of food, in particular meat, worldwide. While increasing the production of broiler meat could be a potential solution to this problem, broiler meat is plagued by health concerns, such as the development of antimicrobial resistance and lower meat quality. For this reason, the supplementation of poultry feed with vitamins and antioxidant compounds, such as polyphenols, has become an attractive prospect for research in this sector. Such supplements could be obtained by extraction of agricultural byproducts (in particular, grape pomaces and artichoke leaves and bracts), thus contributing to reductions in the total amount of waste biomass produced by the agricultural industry. In this review, the effects of poultry feed supplementation with bioactive extracts from grape pomace (skins and/or seeds), as well as extracts from artichoke leaves and bracts, were explored. Moreover, the various methods that have been employed to obtain extracts from these and other agricultural byproducts were listed and described, with a particular focus on novel, eco-friendly extraction methods (using, for example, innovative and biocompatible solvents like Deep Eutectic Solvents (DESs)) that could reduce the costs and energy consumption of these procedures, with similar or higher yields compared to standard methods.

White Grape Pomace Valorization for Remediating Purposes

The present investigation focuses on a possible alternative to reduce grape pomace’s negative impact on the environment by exploiting its capacities for wastewater remediation. Therefore, three directions are followed: (1) the characterization of white grape byproducts’ antioxidant and antiradical properties; (2) the determination of organophosphorus compound concentration that might be present in the samples; and (3) the evaluation of the possible use for wastewater remediation. The grape pomace was used for obtaining different extracts considering different extraction conditions. The hydroalcoholic extracts have an increased amount of total phenolic content. The lyophilized hydroalcoholic extract showed high total phenolic content (159.52 mg/100 g) and low organophosphorus content (0.257 ± 0.015 nmol). The lowest DPPH antiradical-scavenging activities were obtained for the extracts in ethanol obtained from refrigerated pomace (0.055) and for dried pomace (0.045).

Pharmacological actions and underlying mechanisms of Catechin: A review

BACKGROUND

Catechin is a phytochemical and is a major component of our daily use beverages, which has shown great potential in improving general health and fighting against several medical conditions. Clinical studies have confirmed its effectiveness in conditions ranging from acute upper respiratory tract infection, neuroprotection, to cardio-protection effects. Though most studies relate their potential to anti-oxidative action and radical scavenging action, still the mechanism of action is not clearly understood.

OBJECTIVE

The present review article is focused on addressing various pharmacological actions and underlying mechanisms of catechin. Additionally, we will try to figure out the major adverse effect and success in trials with catechin and lead to a conclusion for its effectiveness.

METHODS

This review article is based on the recent/ most cited papers of PubMed and Scopus databases.

DESCRIPTION

Catechin can regulate Nrf2 and NFkB pathways in ways that impact oxidative stress and inflammation by influencing gene expression. Other pathways like MAPKs and COMT and receptor tyrosine kinase are also affected by catechin and EGCG that alter their action and barge the cellular activity. This review article explored the structural aspect of catechin and its different isomers and analogs. It also evaluated its various therapeutic and pharmacological arrays .

CONCLUSION

Catechin and its stereo-isomers have shown their effectiveness as anti-inflammatory, anti-diabetic, anti-cancer, anti-neuroprotective, bactericidal, memory enhancer, anti-arthritis, and hepato-protective mainly through its activity to alter the pathway by NF-κB, Nrf-2, TLR4/NF-κB, COMT, and MAPKs.

Study on the Potential Application of Impatiens balsamina L. Flowers Extract as a Natural Colouring Ingredient in a Pastry Product

Flowers of the genus Impatiens are classified as edible; however, their inclusion in the human diet is not yet a common practice. Its attractive colours have stirred great interest by the food industry. In this sense, rose (BP) and orange (BO) I. balsamina flowers were nutritionally studied, followed by an in-depth chemical study profile. The non-anthocyanin and anthocyanin profiles of extracts of both flower varieties were also determined by high-performance liquid chromatography coupled to a diode array and mass spectrometry detector (HPLC-DAD-ESI/MS). The results demonstrated that both varieties presented significant amounts of phenolic compounds, having identified nine non-anthocyanin compounds and 14 anthocyanin compounds. BP extract stood out in its bioactive properties (antioxidant and antimicrobial potential) and was selected for incorporation in "bombocas" filling. Its performance as a colouring ingredient was compared with the control formulations (white filling) and with E163 (anthocyanins) colorant. The incorporation of the natural ingredient did not cause changes in the chemical and nutritional composition of the product; and although the colour conferred was lighter than presented by the formulation with E163 (suggesting a more natural aspect), the higher antioxidant activity could meet the expectations of the current high-demand consumer.

Anthocyanins from Rubus fruticosus L. and Morus nigra L. Applied as Food Colorants: A Natural Alternative

Given the importance of colour in the general acceptance or rejection of a product, the use of colorants is a widespread practice, particularly in the food industry. At the same time, with the increasing consumers' awareness of the health effects that some artificial colorants can exert, there is a growing tendency to prioritize foodstuffs containing natural additives. In this work, Morus nigra L. and Rubus fruticosus L. fruit juices were characterized in terms of anthocyanins, organic acids, free sugars, and tocopherols, as also regarding their bioactive properties. Given their richness in anthocyanins, this study also aimed to prepare different solid colouring formulations by the spray-drying technique, using as stabilizers maltodextrin and arabic gum. Six free sugars and two organic acids were detected in the fruit juices, as well as the four tocopherol isoforms. Two cyanidin derivatives were found in M. nigra (cyanidin-3-O-glucoside and cyanidin-O-rhamnoside) and other four in R. fruticosus (cyanidin-O-hexoside, cyanidin-3-O-glucoside, cyanidin-O-pentoside, and cyanidin-3-O-dioxaloilglucoside). The developed colouring formulations revealed a good stability over time, in terms of anthocyanin concentration and colour parameters, and revealed to be safe for consumption, either concerning their low microbial load and lack of cytotoxicity. Thus, they represent a promising natural alternative to the massively used artificial colorants.

Valorization of Sicanaodorifera (Vell.) Naudin Epicarp as a Source of Bioactive Compounds: Chemical Characterization and Evaluation of Its Bioactive Properties

Fruit bio-residues can be interesting for the recovery of bioactive molecules, such as phenolic compounds, tocopherols, vitamins, among others. These compounds can be targeted at the food industry and used for the development of functional foods or as food additives. In some cases, fruit epicarps are converted into by-products with non-commercial value, and generally, these fruit parts have a higher content in bioactive compounds than the fruit pulp. From this perspective, S. odorifera, a Brazilian fruit, has an inedible epicarp that could be explored to obtain biological compounds. Therefore, the aims of this study were to evaluate the chemical composition and the antioxidant, anti-proliferative, anti-inflammatory, and antimicrobial bioactivities of this by-product. S. odorifera epicarp showed a total of four organic acids, four phenolic compounds, highlighting the high concentration of anthocyanins (24 ± 1 mg/g dry weight (dw)) and high content of tocopherols (366 ± 2 mg/100 g dw). The hydroethanolic extract showed considerable antioxidant activity (EC₅₀ values of 48.2 ± 0.5 and 27 ± 1 µg/mL for TBARS and OxHLIA assays, respectively), as also antibacterial and antifungal activities (minimal inhibitory concentrations (MICs) ≤ 2.2 mg/mL). The results obtained in this study suggest that Sicana odorifera epicarp represents a reliable option for the development of novel natural-based colorants with functional/bioactive proprieties.

Immunomodulatory Effects of Dietary Polyphenols

Functional and nutraceutical foods provide an alternative way to improve immune function to aid in the management of various diseases. Traditionally, many medicinal products have been derived from natural compounds with healing properties. With the development of research into nutraceuticals, it is becoming apparent that many of the beneficial properties of these compounds are at least partly due to the presence of polyphenols. There is evidence that dietary polyphenols can influence dendritic cells, have an immunomodulatory effect on macrophages, increase proliferation of B cells, T cells and suppress Type 1 T helper (Th1), Th2, Th17 and Th9 cells. Polyphenols reduce inflammation by suppressing the pro-inflammatory cytokines in inflammatory bowel disease by inducing Treg cells in the intestine, inhibition of tumor necrosis factor-alpha (TNF-α) and induction of apoptosis, decreasing DNA damage. Polyphenols have a potential role in prevention/treatment of auto-immune diseases like type 1 diabetes, rheumatoid arthritis and multiple sclerosis by regulating signaling pathways, suppressing inflammation and limiting demyelination. In addition, polyphenols cause immunomodulatory effects against allergic reaction and autoimmune disease by inhibition of autoimmune T cell proliferation and downregulation of pro-inflammatory cytokines (interleukin-6 (IL-6), IL-1, interferon-γ (IFN-γ)). Herein, we summarize the immunomodulatory effects of polyphenols and the underlying mechanisms involved in the stimulation of immune responses.

Extracts from Vaccinium myrtillus L. fruits as a source of natural colorants: chemical characterization and incorporation in yogurts

The food industry is always seeking innovative approaches to maintain consumers' interest and increase their awareness towards the healthiness of diets. Therefore, much interest has been given to natural food additives, namely colourants. In this work, a bilberry extract was primarily characterized in terms of anthocyanin compounds by UPLC-DAD-ESI/MSn, and its colouring capacity was further compared with a synthetic anthocyanin colourant (E163) in different yogurt formulations. The prepared samples were evaluated in different periods (0 and 7 days) for nutritional profile, individual fatty acids, soluble sugars and external colour to determine the effects of each additive. Overall, the major anthocyanin compounds in bilberry were malvidin glycoside and delphinidin glycoside derivatives. With regard to the prepared yogurts, all samples maintained the nutritional profile, individual fatty acids and soluble sugars, independent of storage time. Nonetheless, bilberry extracts showed lower colouring capacity when compared to that of E163, despite the higher stability of bilberry extract throughout the storage time, when compared to that of E163. Furthermore, another advantage of this natural extract is that it has potential bioactive properties that can be conferred to foods, due to their high content of bioactive compounds, such as anthocyanins.

Actions of multiple doses of resveratrol on oxidative and inflammatory markers in plasma and brain of healthy and arthritic rats

The actions of resveratrol in brain and plasma of rats with adjuvant-induced arthritis were investigated. Resveratrol was administered orally during a period of 23 days. A major concern of the present work was to explore an ample range of daily doses (10-200 mg/kg). Several oxidative and inflammatory markers were measured. Important effects of resveratrol treatment were the normalization of the plasma myeloperoxidase activity (inflammatory marker), the normalization of the brain xanthine oxidase activity (reactive oxygen species source) and the near-normalization of the catalase activity in the brain (antioxidant defence). These effects presented obvious dose dependencies in the range up to 200 mg/kg. Resveratrol also reduced protein and lipid damage within the lowest dose ranges investigated, and its action as a free radical scavenger activity was enhanced in brain mitochondria of arthritic rats. Resveratrol failed in restoring the diminished albumin levels and plasma protein thiols in arthritic rats. The latter, however, were substantially increased in healthy rats at low doses (up to 50 mg/kg), a sign of antioxidant action. This increase was reversed at higher doses, a sign of pro-oxidant action. The observations agree with the notion that low doses of resveratrol might be useful as an adjuvant to the conventional antirheumatic drugs.

Extraction of Anthocyanins from Red Raspberry for Natural Food Colorants Development: Processes Optimization and In Vitro Bioactivity

Heat (HAE)- and ultrasound (UAE)-assisted extraction methods were implemented to recover anthocyanins from red raspberry. Processing time, ethanol concentration, and temperature or ultrasonic power were the independent variables combined in five-level rotatable central composite designs coupled with response surface methodology (RSM) for processes optimization. The extraction yield and levels of cyanidin-3-O-sophoroside (C3S) and cyanidin-3-O-glucoside (C3G) were monitored by gravimetric and HPLC-DAD-ESI/MSn methods, respectively, and used as response criteria. The constructed theoretical models were successfully fitted to the experimental data and used to determine the optimal extraction conditions. When maximizing all responses simultaneously, HAE originated slightly higher response values (61% extract weight and 8.7 mg anthocyanins/g extract) but needed 76 min processing at 38 °C, with 21% ethanol (v/v), while the UAE process required 16 min sonication at 466 W, using 38% ethanol (v/v). The predictive models were experimentally validated, and the purple-red extracts obtained under optimal condition showed antioxidant activity through lipid peroxidation and oxidative hemolysis inhibition, and antibacterial effects against food-related microorganisms, such as Escherichia coli and Enterococcus faecalis. These results highlight the potential of red raspberry extracts as natural food colorants with bioactive effects and could be exploited by industries interested in the production of anthocyanin-based products.

In Vitro Bioaccessibility of Extractable Compounds from Tannat Grape Skin Possessing Health Promoting Properties with Potential to Reduce the Risk of Diabetes

Diabetes pathogenesis encompasses oxidative stress, inflammation, insulin malfunctioning and partial or total insulin secretion impairment, which leads to a constant hyperglycemia. Polyphenols are known to possess bioactive properties, being Tannat grape skin a natural and sustainable source of these compounds. The present study aimed to find out the bioaccessibility of health-promoting molecules composing a multifunctional extract from Tannat grape skin obtained under hydro-alcoholic-acid conditions. The identification of phenolic compounds in the samples was performed by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Subsequently, the samples were in vitro digested mimicking the human oral gastrointestinal conditions and the bioactivity of the digest (antioxidant, anti-inflammatory and modulation of glucose metabolism) was assessed. Effect on glucose metabolism was estimated by measuring carbohydrases activity and the functionality of glucose transporters of small intestine cells in presence and absence of the digested extract. Flavonoids, phenolic acids and phenolic alcohols were the major phenol compounds detected in the extract. The bioaccessible compounds protected the intestinal cells and macrophages against the induced formation of reactive oxygen species (ROS) and nitric oxide (NO). In addition, glucose transporters were inhibited by the digested extract. In conclusion, the bioaccessible compounds of the extract, including phenols, modulated key biochemical events involved in the pathogenesis of diabetes such as oxidative stress, inflammation and glucose absorption. The extract was effective under prevention with co-administration conditions supporting its potential for either reducing the risk or treating this disease.

Compositional Features of the "Kweli" Red Raspberry and Its Antioxidant and Antimicrobial Activities

Red raspberries (Rubus idaeus L.) are increasingly popular foods in contemporary diets due to their freshness, nutritional value and health claims. Among the existing cultivars, "Kweli" is one of the most productive and widely cultivated. In this study, the nutritional value and chemical composition of "Kweli" red raspberry were characterized by the official method of food analysis and chromatographic techniques, and its antioxidant and antimicrobial activities were tested against biological/biochemical oxidizable substrates and foodborne bacteria and fungi strains, respectively. Carbohydrates (including fructose and glucose, 14.3 and 12.6 g/100 g dw, respectively), proteins (6.8 g/100 g dw), and ashes (3.90 g/100 g dw) were major constituents. The fat content was quite low and constituted mainly by unsaturated fatty acids (58.3%), with a predominance of oleic acid. Fresh red raspberry also contained high levels of citric (2.7 g/100 g) and ascorbic (17 mg/100 g) acids. The anthocyanins (4.51 mg/g extract) cyanidin-O-hexoside and mostly cyanidin-O-sophoroside were identified in the red raspberry hydroethanolic extract, which was able to inhibit thiobarbituric acid reactive substances (TBARS) formation (EC50 of 122 µg/mL), oxidative hemolysis (IC50 of 298 µg/mL), and β-carotene bleaching (EC50 of 18.7 µg/mL). In turn, the extract was more effective than the food additive E224 against Bacillus cereus. All these results highlighted the nutritional quality of "Kweli" red raspberry and showed some compositional differences in relation to other cultivars. Therefore, its inclusion in a daily diet can be helpful to obtain nutrients and antioxidants and bring health benefits.

Potential anti-diabetic properties of Merlot grape pomace extract: An in vitro, in silico and in vivo study of α-amylase and α-glucosidase inhibition

A practical approach to control glycemia in diabetes is to use plant natural products that delay hydrolysis of complex sugars and promote the diminution of the release of glucosyl units into the blood plasma. Polyphenolics have been described as being effective in inhibiting amylases and α-glucosidases. Grape pomace is an important sub product of the wine industry, still rich in many compounds such as polyphenolics. In this context, the purpose of this study was to search for possible effects of a grape pomace extract on salivary and pancreatic α-amylases and α-glucosidase, as well as on intestinal glucose absorption. The Merlot grape pomace extract (MGPE) was prepared using a hydroalcoholic mixture (40% ethanol + 60% water). In vitro inhibition was quantified using potato starch (for amylases) and maltose (for α-glucosidase) as substrates. In vivo inhibition was evaluated by running starch and maltose tolerance tests in rats with or without administration of MGPE. Ranking of the extract compounds for its affinity to the α-amylases was accomplished by computer simulations using three different programs. Both α-amylases, pancreatic and salivary, were inhibited by the MGPE. No inhibition on α-glucosidase, however, was detected. The IC₅₀ values were 90 ± 10 μg/mL and 143 ± 15 μg/mL for salivary and pancreatic amylases, respectively. Kinetically this inhibition showed a complex pattern, with multiple binding of the extract constituents to the enzymes. Furthermore, the in silico docking simulations indicated that several phenolic substances, e.g., peonidin-3-O-acetylglucoside, quercetin-3-O-glucuronide and isorhamnetin-3-O-glucoside, besides catechin, were the most likely polyphenols responsible for the α-amylase inhibition caused by MGPE. The hyperglycemic burst, an usual phenomenon that follows starch administration, was substantially inhibited by the MGPE. Our results suggest that the MGPE can be adequate for maintaining normal blood levels after food ingestion.

Vasorelaxant Effects Induced by Red Wine and Pomace Extracts of Magliocco Dolce cv

Several epidemiological studies demonstrate that moderate (red) wine consumption may afford protection against cardiovascular diseases. Protection is ascribed to the biological activity of wine components, many of which, however, are discarded during winemaking. In vitro rat thoracic aorta rings contracted with phenylephrine or KCl were used to assess the vasorelaxant activity of extracts from wine pomaces (seeds and skins) of the Calabrian autochthonous grape variety Magliocco dolce (Arvino). NMR spectroscopy was used to ascertain their chemical composition. Data demonstrate that seed and skin, but not must, extracts are capable of relaxing vascular preparations in an endothelium-dependent manner, similarly to the red wine extract, due to the presence of comparable amounts of bioactive constituents. In rings pre-contracted with 20–30 mM KCl, only seed extracts showed a moderate relaxation. The most efficacious vasodilating extract (wine) showed a good antioxidant profile in both [(2,2-diphenyl-1-picrylhydrazyl)acid] radical (DPPH) and [2,2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid)] radical (ABTS) assays. In conclusion, winemaking from Magliocco dolce grape can provide potentially health-promoting by-products useful in cardiovascular disease management.

Characterization and Application of Pomegranate Epicarp Extracts as Functional Ingredients in a Typical Brazilian Pastry Product

Currently, there is a clear tendency to incorporate natural ingredients into food and pharmaceutical formulations. Besides being well-accepted by consumers, these ingredients have less adverse side effects than their artificial counterparts. The pomegranate processing industry produces large quantities of by-products that are discarded as bio-residues, despite containing bioactive compounds. Accordingly, the epicarp of two pomegranate varieties (Mollar de Elche and Purple Queen) was tested as a potential source of bioactive compounds with food application. The phenolic profile was identified by HPLC–DAD–ESI/MS, revealing fourteen phenolic compounds in both varieties (Purple Queen showed also three anthocyanins), with punicalagin isomers as the major compounds. Nonetheless, Mollar de Elche presented greater antioxidant and antibacterial activities. Despite this result, Purple Queen was selected to be tested as a new natural colouring and functionalizing ingredient in a Brazilian pastry product. The incorporation of the selected extract maintained the nutritional profile and provided a higher antioxidant activity compared to the traditional product. In this way, this work confirmed the possible use of pomegranate epicarp as a natural ingredient in the food industry, conferring dyeing and functionalizing effects, and anticipating a possible valorisation of this bio-residue.

Anthocyanin-rich extract of jabuticaba epicarp as a natural colorant: Optimization of heat- and ultrasound-assisted extractions and application in a bakery product

Heat- and ultrasound-assisted extractions of anthocyanins from jabuticaba epicarp were optimized and the colouring potential of the developed extract was tested on macarons. The independent variables time (t), solvent concentration (S), and temperature (T) or power (P) were combined in a five-level central composite design coupled with response surface methodology. The delphinidin-3-O-glucoside and cyanidin-3-O-glucoside levels monitored by HPLC-DAD-ESI/MS were used as response criteria. The developed models were successfully fitted to the experimental data and used to determine optimal extraction conditions. HAE was the most efficient method yielding 81 ± 2 mg/g extract under optimal conditions (t = 21.8 min, T = 47.1 °C and S = 9.1% ethanol, v/v). Macarons were then produced using the optimized anthocyanin-rich colouring extract and their colour parameters and nutritional profile were monitored during shelf-life. The obtained results provided useful information for the development of anthocyanin-rich extracts from a bio-waste with potential use as natural food colorants.

By-Products of Camu-Camu [Myrciaria dubia (Kunth) McVaugh] as Promising Sources of Bioactive High Added-Value Food Ingredients: Functionalization of Yogurts

Camu-camu (Myrciaria dubia (Kunth) McVaugh) is a fruit economically relevant to the Amazon region, mostly consumed in the form of processed pulp. Our aim was to perform an unprecedented comparative study on the chemical composition and bioactivities of the camu-camu pulp and industrial bio-residues (peel and seed), and then the most promising fruit part was further explored as a functionalized ingredient in yogurt. A total of twenty-three phenolic compounds were identified, with myricetin-O-pentoside and cyanindin-3-O-glucoside being the main compounds in peels, followed by p-coumaroyl hexoside in the pulp, and ellagic acid in the seeds. The peel displayed the richest phenolic profile among samples, as well as the most significant antibacterial (MICs = 0.625–10 mg/mL) and anti-proliferative (GI₅₀ = 180 µg/mL against HeLa cells) activities. For this reason, it was selected to be introduced in a food system (yogurt). Taken together, our results suggest the possibility of using the camu-camu peel as a source of food additives.

Ocimum basilicum var. purpurascens leaves (red rubin basil): a source of bioactive compounds and natural pigments for the food industry

Ocimum basilicum var. purpurascens (red rubin basil) is a basil variety rich in anthocyanin compounds, commonly used in the food industry as an aromatic plant. In this study, the nutritional and chemical compositions of red rubin basil leaves were analysed, as well as, the antimicrobial activity and hepatotoxicity of their hydroethanolic extract. Carbohydrates were the main macronutrients present, with glucose being the major free sugar. Quinic acid was the most abundant organic acid, while γ-tocopherol was the highest tocopherol isoform found. α-Linolenic acid was the major fatty acid of the twenty identified compounds. Regarding polyphenols, twenty-six molecules were identified (thirteen non-anthocyanin and thirteen anthocyanin compounds), with rosmarinic acid being the main non-anthocyanin molecule and cyanidin-3-(6,6'-di-p-coumaroyl)-sophoroside-5-glcucoside the most abundant anthocyanin. These compounds could be related to the antimicrobial activity observed in this study. Thus, this variety could be considered a good source of value added molecules for the food industry.

Chemical composition and bioactive properties of byproducts from two different kiwi varieties

Kiwis are an example of fruits with excellent bioactive properties worldwide appreciated and consumed generating tons of waste. Thus, the objective of this work was to compare two varieties of kiwi: Actinidia deliciosa cv. "Hayward" (green) and Actinidia spp. (red) regarding the nutritional value of their pulps, chemical composition and bioactivities of each pulp and peel. The results revealed that pulps have a high water content and low amount of other macronutrients. Both parts of red kiwi presented the highest tocopherols content and red kiwi pulp presented the highest content in ascorbic acid. In general, the peels exhibited the highest antioxidant activity and green kiwi peels showed cytotoxicity and anti-inflammatory activity, which could be related to its higher content in phenolic compounds, especially B-type (epi)catechin dimer. Therefore, kiwi components currently underutilized may be indicated as a source of natural functionalizing ingredients with several benefits for human health.

Promising Antioxidant and Antimicrobial Food Colourants from Lonicera caerulea L. var. Kamtschatica

Lonicera caerulea L. (haskap) berries are widely known for their richness in anthocyanins. In this study, such fruits were assessed for their nutritional and chemical composition, but also as sources of anthocyanins with great colouring properties to be applied in foodstuff. Haskap presented high levels of water, four free sugars (mainly fructose and glucose), five organic acids (mainly citric, malic, and quinic), α- and γ-tocopherol, twenty fatty acids (with prevalence of linoleic acid), and eight phenolic compounds, among which six were anthocyanins (mainly cyanidin-3-O-glucoside). The extract presented great antioxidant properties, evaluated through TBARS and OxHLIA assays, as well as antimicrobial capacity against six bacteria and six fungi. Two colourants were obtained by spray-drying haskap juice with maltodextrin and a mixture of maltodextrin and arabic gum. These formulations were stable over 12 weeks of storage at room and refrigerated temperature, without significant variations in colour parameters and in anthocyanins concentration. They were considered safe for consumption once neither microbial contamination nor cytotoxicity in non-tumour cells were detected. The results obtained allow for the consideration of haskap as a promising source of colourants to be applied not only in the food industry, but also in other fields that rely on artificial colourants.

Viola cornuta and Viola x wittrockiana: Phenolic compounds, antioxidant and neuroprotective activities on Caenorhabditis elegans

Different Viola species are known for their traditional use as analgesic, antitussive, febrifuge, hipnotic, analgesic and anti-inflammatory medicinal agents. Additionally, they are considered edible flowers in certain cultures. Thus, the aim of this work was to characterize the phenolic composition and to assess the neuroprotective properties of Viola cornuta and Viola x wittrockiana using in vitro and in vivo methodologies with Caenorhabditis elegans as model. The identification of the phenolic compounds was carried out with a LC-DAD-ESI/MSn. The antioxidant activity of the extracts was determined in vitro using Folin-Ciocalteu, DPPH and FRAP assays and in vivo with a juglone-induced oxidative stress in C. elegans. The neuroprotective properties were evaluated measuring the ability to inhibit CNS enzymes (MAO A, AChE), and the capability to avoid paralyzing the C. elegans CL4176, an Alzheimer disease model. The phenolic content was higher in V. x wittrockiana, being quercetin-3-O-(6-O-rhamnosylglucoside)-7-O-rhamnoside the predominant compound in the extract, which also exhibited a stronger antioxidant capacity in vitro and a higher response to lethal oxidative stress on C. elegans than V. cornuta. Only V. x wittrockiana showed inhibitory effect on CNS enzymes, such as acetylcholinesterase and monoamine oxidase A, but both had protective effect against the paralysis of C. elegans. These findings suggest that the studied V. cornuta and V. x wittrockiana could be interesting candidates for age related neurodegenerative disorder associated with oxidative stress.

Optimization of the Extraction Process to Obtain a Colorant Ingredient from Leaves of Ocimum basilicum var. purpurascens

Heat-Assisted Extraction (HAE) was used for the optimized production of an extract rich in anthocyanin compounds from Ocimum basilicum var. purpurascens leaves. The optimization was performed using the response surface methodology employing a central composite experimental design with five-levels for each of the assessed variables. The independent variables studied were the extraction time (t, 20–120 min), temperature (T, 25–85 °C), and solvent (S, 0–100% of ethanol, v/v). Anthocyanin compounds were analysed by HPLC-DAD-ESI/MS and the extraction yields were used as response variables. Theoretical models were developed for the obtained experimental data, then the models were validated by a selected number of statistical tests, and finally, those models were used in the prediction and optimization steps. The optimal HAE conditions for the extraction of anthocyanin compounds were: t = 65.37 ± 3.62 min, T = 85.00 ± 1.17 °C and S = 62.50 ± 4.24%, and originated 114.74 ± 0.58 TA mg/g of extract. This study highlighted the red rubin basil leaves as a promising natural matrix to extract pigmented compounds, using green solvents and reduced extraction times. The extract rich in anthocyanins also showed antimicrobial and anti-proliferative properties against four human tumor cell lines, without any toxicity on a primary porcine liver cell line.

Ultrasound as a Rapid and Low-Cost Extraction Procedure to Obtain Anthocyanin-Based Colorants from Prunus spinosa L. Fruit Epicarp: Comparative Study with Conventional Heat-Based Extraction

An ultrasound rapid and low-cost procedure for anthocyanin-based colorants from Prunus spinosa L. fruit epicarp was developed, and the advantages were compared with conventional heat-based extraction. To obtain the conditions that maximize anthocyanins' extraction, a response surface methodology was applied using the variables of time, temperature, and ethanol content, in the case of heat extraction, whereas for ultrasound assisted extraction, temperature was replaced by ultrasound power. Two anthocyanin compounds were identified by HPLC-DAD-ESI/MS-namely, cyanidin 3-rutinoside and peonidin 3-rutinoside. The responses used were the extraction yield and the content of the identified anthocyanins. Ultrasound extraction was the most effective method at 5.00 ± 0.15 min, 400.00 ± 32.00 W, and 47.98% ± 2.88% of ethanol obtaining 68.60% ± 2.06% of extracted residue, with an anthocyanin content of 18.17 mg/g (extract-basis) and 11.76 mg/g (epicarp-basis). Overall, a viable green process was achieved that could be used to support pilot-scale studies for industrial production of anthocyanin-based colorants from P. spinosa fruit epicarp.

Rubus ulmifolius Schott fruits: A detailed study of its nutritional, chemical and bioactive properties

There is a growing interest in wild edible species that represent a source of several health-promoting compounds, providing a potential strategy to diversify and enrich the daily diet. The aim of the present work was to characterize the nutritional and chemical composition of Rubus ulmifolius Schott fruits. Furthermore, their antimicrobial activity, non-anthocyanin and anthocyanin phenolic profile were also determined. According to the obtained results, R. ulmifolius fruits exhibited a high concentration in carbohydrates and a low fat content, in comparison with the other nutrients and non-nutrients detected in this sample. The colour parameters demonstrated differences in a* and b* parameters after lyophilisation process. Glucose and fructose were the most abundant free sugars detected and quinic acid showed the highest content compared to the other five organic acids identified. The fatty acids profile revealed 25 compounds, being mostly represented by polyunsaturated fatty acids and evidencing linolenic and α-linolenic acid as the most abundant. All tocopherol isoforms were detected, revealing γ-tocopherol with highest amount. Cyanidin-3-O-glucoside, ellagic acid pentoside, ellagic acid glucuronide and sanguiin H-10 were the main phenolic compounds present, which could be related to the antimicrobial activity (MIC values ranging between 5 and 20 mg/mL) revealed by R. ulmifolius fruits. These results showed that this fruit is a good source of nutrients as also non-nutrient compounds, with human health benefits.

Grape pomace as a source of phenolic compounds and diverse bioactive properties

The bio-residues resulting from the wine industry (grape pomace made up of skins, seeds and stems) are often undervalued but constitute a potential source of bioactive phenolic compounds that can be applied in several industries. In this context, the aim of the present study was to evaluate the phenolic profile of Vitis vinifera L. grape pomace (skins, seeds and their mixture), and correlate them with its antioxidant, cytotoxic and antibacterial activities. The seeds showed the highest amount of phenolic compounds and also the highest antioxidant, cytotoxic and antibacterial activities. The skins revealed the highest levels of anthocyanins and p-coumaric acid hexoside. Strong correlations were observed between the presence of phenolic compounds and all the bioactivities studied. These by-products are good sources of phenolic compounds with high antioxidant and antibacterial activity, and also presenting a moderate cytotoxicity activity. These added-value by-products have great applicability in food, pharmaceutical and cosmetic industries.

Recovery of bioactive anthocyanin pigments from Ficus carica L. peel by heat, microwave, and ultrasound based extraction techniques

Due to its coloration, the fig (Ficus carica L.) peel, a by-product of fruit processing and/or consumption, is a potential source of anthocyanin compounds. In the present study different extraction techniques (heat, ultrasound, and microwave) were compared aiming to recover the anthocyanin pigments and optimize its extraction conditions. A response surface methodology tool with three factors and five levels for each factor was used according to a circumscribed central composite design. The variables tested for the heat and microwave extraction methods were time, temperature, and solvent proportion (ethanol/water ratio), meanwhile, for the ultrasound method, the variables tested were the ultrasonic power, time, and solvent proportion. The anthocyanin composition of the extract was determined by HPLC-DAD-ESI/MS, and the used criteria responses were: i) quantification of cyanidin 3-rutinoside (C) in the extracted residue (mg C/g R) and in the dried peel (mg C/g P dw), and the extraction yield of the obtained residue (g R/g P dw). Ultrasound extraction was the most effective method, yielding 3.82 mg C/g R at the optimal global extraction conditions (21 min, 310 W, and 100% of ethanol). Additionally, the solid-to-liquid ratio effect was studied at the optimal conditions, using a dose-response format, in view of its plausible transference to industrial level. For the ultrasound method, an increased non-linear relationship was observed for concentrations in the range 5 to 200 g/L, being the optimal solution close to 150 g/L. In brief, the obtained results show the potential of fig peels as a source of anthocyanin pigments, with potential uses in various industrial fields, such as food, pharmaceutical, and cosmetic.

Correlações entre compostos fenólicos e atividade antioxidante em casca e polpa de variedades de uva de mesa

Resumo Uvas são consideradas excelentes fontes de compostos fenólicos, quando comparadas a outros vegetais; porém, a grande diversidade entre as cultivares resulta em frutos com diferentes características, tanto de sabor quanto de coloração, o que, certamente, está associado com o conteúdo e o perfil de compostos polifenólicos. Cascas e polpas de amostras de uva no ponto de consumo − tipos “Itália”, “Brasil”, “Rubi”, “Thompson” e “Niágara Rosada” − da região de Campinas e Jundiaí, Estado de São Paulo, foram estudadas com o objetivo de avaliar a atividade antioxidante, a atividade enzimática da peroxidase e da polifenoloxidase e os teores de compostos fenólicos e de ácido ascórbico. A fim de verificar as correlações entre as cascas e polpas das variedades e as características, utilizou-se a Correlação de Pearson, a distância generalizada de Mahalanobis (D2) e, por fim, o agrupamento das diferentes respostas através da análise multivariada. Verificou-se que as cascas das uvas analisadas apresentaram correlação positiva com o conteúdo de compostos fenólicos, a atividade da enzima polifenoloxidase e com o teor de ácido ascórbico, exceto a cultivar “Niágara Rosada”, a qual mostrou maiores valores para estas avaliações. Não houve correlação entre o índice de atividade antioxidante com as demais análises realizadas. As cascas se mostraram uma ótima fonte para estes compostos.