Low molecular weight phenolics of grape juice and winemaking byproducts: antioxidant activities and inhibition of oxidation of human low-density lipoprotein cholesterol and DNA strand breakage

Phenolic composition and encapsulation of Brazilian grape seed extracts: evaluating color stabilizing capacity in grape juices

The color of grape juice is an important acceptance attribute by consumers, but it suffers losses during storage. The use of commercial antioxidants has limitations because the concept of a "100% natural drink" of Brazilian legislation. This work characterized Brazilian grape seeds, and the cultivar extract with the greatest potential was encapsulated in arabic-gum (encapsulated extract-EE) to evaluate the color stabilizing capacity. The EE used in the grape juice was compared with the commercial antioxidants sulphite and enological tannin during storage (150 days). The BRS Magna and BRS Violeta grape seeds had the highest phenolic content, and the EE showed high catechin (4108 mg/kg), epicatechin (1161 mg/kg) and procyanidin-B2 (905 mg/kg) values. Sulfite was found to be the best color stabilizer. The use of EE (0.5 g/L) in grape juice improved color stability and anthocyanin stability. It was demonstrated that encapsulated grape seed extract has color stabilizing potential and that Brazilian grape seeds are a raw material of high technological value.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-024-05956-8.

Polyphenol Composition by HPLC-DAD-(ESI-)MS/MS and Bioactivities of Extracts from Grape Agri-Food Wastes

BACKGROUND

Grape agri-food wastes, such as skin, seeds, and other discarded by-products, contain phytochemical compounds that offer potential health benefits.

METHODS

This study aimed to investigate the polyphenol composition and bioactivities of different extracts obtained from grape marc and seeds, with the goal of exploring their potential for application as natural food additives.

RESULTS

Regardless of the extraction method used (dynamic maceration, ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE)), all extracts exhibited relatively high concentrations of phenolic compounds. The chemical characterization of the extracts revealed the presence of specific compounds and chemical groups associated with each extraction methodology. Moreover, the extracts displayed satisfactory antioxidant activities, especially in inhibiting lipoperoxidation as assessed by the TBARS assay. Additionally, the extracts demonstrated effective inhibition against different strains of bacteria and fungi known as food contaminants. Taken together, these findings indicate that those extracts have the potential to be tested as natural antioxidants and preservatives with sustainable origins in food and beverage systems. Among the extraction methods evaluated, traditional maceration and UAE provided extracts with the highest antioxidant and antimicrobial activities.

CONCLUSIONS

Our results suggest the opportunity to explore grape marc and seeds discarded by the winery industry in Portugal as natural sources of bioactive compounds, which could be employed as functional food ingredients or technological additives. The valorization of grape biowastes offers a promising strategy to reduce waste and harness their potential health benefits.

Phenolic Profile and the Antioxidant, Anti-Inflammatory, and Antimicrobial Properties of Açaí (Euterpe oleracea) Meal: A Prospective Study

The mechanical extraction of oils from Brazilian açaí (Euterpe oleracea Mart) produces significant amounts of a byproduct known as "meal", which is frequently discarded in the environment as waste material. Nevertheless, plant byproducts, especially those from oil extraction, may contain residual polyphenols in their composition and be a rich source of natural bioactive compounds. In this study, the phenolic composition and in vitro biological properties of a hydroethanolic açaí meal extract were elucidated. The major compounds tentatively identified in the extract by high-resolution mass spectrometry were anthocyanins, flavones, and flavonoids. Furthermore, rhamnocitrin is reported in an açaí byproduct for the first time. The extract showed reducing power and was effective in scavenging the ABTS radical cation (820.0 µmol Trolox equivalent∙g^-1) and peroxyl radical (975.7 µmol Trolox equivalent∙g^-1). NF-κB activation was inhibited at 10 or 100 µg∙mL^-1 and TNF-α levels were reduced at 100 µg∙mL^-1. However, the antibacterial effects against ESKAPE pathogens was not promising due to the high concentration needed (1250 or 2500 µg∙mL^-1). These findings can be related to the diverse polyphenol-rich extract composition. To conclude, the polyphenol-rich extract obtained from açaí meal showed relevant biological activities that may have great applicability in the food and nutraceutical industries.

Potential implications of polyphenolic compounds in neurodegenerative diseases

Neurodegenerative diseases are common chronic diseases related to progressive damage to the nervous system. Current neurodegenerative diseases present difficulties and despite extensive research efforts to develop new disease-modifying therapies, there is still no effective treatment for halting the neurodegenerative process. Polyphenols are biologically active organic compounds abundantly found in various plants. It has been reported that plant-derived dietary polyphenols may improve some disease states and promote health. Emerging pieces of evidence indicate that polyphenols are associated with neurodegenerative diseases. This review aims to overview the potential neuroprotective roles of polyphenols in most common neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, epilepsy, and ischemic stroke.

Autofluorescence-Based Investigation of Spatial Distribution of Phenolic Compounds in Soybeans Using Confocal Laser Microscopy and a High-Resolution Mass Spectrometric Approach

In this research, we present a detailed comparative analysis of the bioactive substances of soybean varieties k-11538 (Russia), k-11559 (Russia), k-569 (China), k-5367 (China), k-5373 (China), k-5586 (Sweden), and Primorskaya-86 (Russia) using an LSM 800 confocal laser microscope and an amaZon ion trap SL mass spectrometer. Laser microscopy made it possible to clarify in detail the spatial arrangement of the polyphenolic content of soybeans. Our results revealed that the phenolics of soybean are spatially located mainly in the seed coat and the outer layer of the cotyledon. High-performance liquid chromatography (HPLC) was used in combination with an amaZon SL BRUKER DALTONIKS ion trap (tandem mass spectrometry) to identify target analytes in soybean extracts. The results of initial studies revealed the presence of 63 compounds, and 45 of the target analytes were identified as polyphenolic compounds.

Therapeutic and Nutraceutical Effects of Polyphenolics from Natural Sources

The prevalence of cardiovascular disease, oxidative stress-related complications, and chronic age-related illnesses is gradually increasing worldwide. Several causes include the ineffectiveness of medicinal treatment therapies, their toxicity, their inability to provide radical solutions in some diseases, and the necessity of multiple drug therapy in certain chronic diseases. It is therefore necessary for alternative treatment methods to be sought. In this review, polyphenols were identified and classified according to their chemical structure, and the sources of these polyphenol molecules are indicated. The cardioprotective, ROS scavenging, anti-aging, anticancer properties of polyphenolic compounds have been demonstrated by the results of many studies, and these natural antioxidant molecules are potential alternative therapeutic agents.

Exploring potential antidiabetic and anti-inflammatory flavonoids from Euphorbia humifusa with an integrated strategy

E. humifusa Willd, a monoecious annual plant, native to Eastern Asia, has been traditionally attributed to the treatment and prevention of miscellaneous diseases, including diabetes mellitus and its associated complications. Earlier studies have supported this species’ pharmacological efficacies including its antibacterial, antidiabetic, and anti-inflammatory properties. Even so, the underlying bioactive components with their mechanisms of action associated with its antidiabetic and anti-inflammatory effects remain elusive. The preamble in vitro assessments of the crude extract and its different fractions revealed that the n-butanol fraction (EHNB) exhibited the best activity, which was subsequently subjected to a rapid screening of candidate ligands through bio-affinity ultrafiltration with the two enzyme targets: α-glucosidase (α-Glu) and cycloxygenase-2 (COX-2) combined with UPLC/QTOF-MS. As a result, 7 compounds were identified from EHNB, among them, vitexin and astragalin were screened out as the most active ligand compounds. Vitexin showed great specific binding (SB) affinity values of 1.26 toward α-Glu and 1.32 toward COX-2, while astragalin showed 1.32 and 1.36, respectively. The docking simulation results exhibited strong interactions of vitexin and astragalin with the key residues of the enzyme targets, suggesting their possible mechanisms of action. The in vitro antidiabetic validation revealed noticeable half-maximal inhibitory effects (IC₅₀) of 36.38 ± 3.06 µM for vitexin and 42.47 ± 4.13 µM for astragalin, much better than that of the positive drug acarbose (109.54 ± 14.23 µM). Similarly, these two compounds showed the inhibitory activity against COX-2 with the half-maximal inhibitory effects (IC₅₀) at 27.91 ± 1.74 µM and 49.05 ± 1.49 µM, respectively. Therefore, these two flavonoid compounds (vitexin and astragalin) were speculated as potential antidiabetic and anti-inflammatory compounds from E. humifusa. Taken together, the integrated strategy applied to E. humifusa led to the fast identification of two potential double-acting flavonoids and enlightened its antidiabetic and anti-inflammatory uses. Besides these findings, the integrated strategy in this study could also be used to facilitate the rapid discovery and development of active candidates from other traditional herbal medicines against multi-drug targets and to aid in revealing their mechanisms of action for their traditional uses.

Steam explosion enhances phenolic profiles and antioxidant activity in mung beans

Steam explosion (SE), as a physicochemical pretreatment process, has the dual effect of high temperature and high pressure. In this study, SE was applied to pretreat mung beans to increase phenolic extraction and their antioxidant activity. It can make the material loose and porous, which is beneficial to the release of phenolic compounds from mung beans. Insoluble‐bound phenolics (IBPs) were the dominating fraction, followed by glycosidic phenolics (GPs) and esterified phenolics (EPs), and free phenolics (FPs) were the lowest in mung beans. After SE, the maximum contents of FPs, EPs, GPs, IBPs, and total phenolics were detected at 0.75 MPa for 30 s, which were 1.47‐, 1.87‐, 1.73‐, 1.48‐, and 1.58‐fold compared with the untreated samples, respectively. On the whole, the effect of SE on phenolics in mung beans first increased and then decreased. SE increased the contents of protocatechuic acid, p‐coumaric acid, ferulic acid, catechin, and epicatechin; but there was a decrease in caffeic acid. Compared with the untreated samples, the antioxidant activity of FPs, GPAs, EPs, and IBPs was also improved by SE. The relationship between the phenolic content and antioxidant activity was very high with coefficients of 2,2′‐azinobis (3‐ethylbenzothiazoline‐6‐ sulfonic acid) > 2,2′‐diphenyl‐1‐picrylhydrazyl > ferric reducing antioxidant power. In conclusion, an appropriate SE can lead to a more efficient extraction of phenolics and improvement of antioxidant activity in mung beans.

Honeybee Pollen From Southern Chile: Phenolic Profile, Antioxidant Capacity, Bioaccessibility, and Inhibition of DNA Damage

Honeybee pollen (HBP) chemical composition is highly variable conforming to the floral and geographical origin of the pollen grains. The beneficial effects and functional properties of the HBP are well-known and have been mainly attributed to their high content of antioxidant polyphenols. In this work, twelve HBPs samples from the Southern region of Chile (X Región de Los Lagos) were characterized for the first time according to their botanical origin, phenolic composition, and antioxidant activity. The in vitro gastrointestinal digestion assay was done to simulate the human upper digestive tract. Selected honeybee pollen extracts (HBPEs) were assessed as bioaccessible fractions during an in vitro gastrointestinal digestion. Contents of phenolic compounds, antioxidant capacity, and recovery index of quercetin, myricetin, and cinnamic acid were monitored in different steps of gastrointestinal digestion. Furthermore, the protective effect of in vitro digested HBP towards DNA damage induced by peroxyl radicals was evaluated. The introduced species Brassica rapa L. (Brassicaceae), Lotus pedunculatus Cav. (Fabaceae), and Ulex europaeus L. (Fabaceae) predominated in all the HBPs analyzed, while the native species Buddleja globosa Hope (Scrophulariaceae), Luma apiculata (DC.) Burret (Myrtaceae), Embothrium coccineum J.R. Forst. & G. Forst. (Proteaceae) and Eucryphia cordifolia Cav. (Cunoniaceae) appeared less frequently. The content of polyphenols and antioxidant capacity in HBPEs achieved full bioaccessibility at the end of the intestinal digestion step. However, results obtained by a state-of-the-art technique (i.e. HPLC-DAD) demonstrated relatively low values of bioaccessible quercetin and cinnamic acid after the digestion process. In contrast, myricetin showed a high bioaccessibility in the intestinal digestion steps. The protective effect of in vitro digested HBP towards DNA damage induced by peroxyl radicals showed promising results (up to 91.2% protection). In conclusion, HBPs from the X Region de Los Lagos are rich sources of phenolic antioxidants that protect DNA from strand breakage. Therefore, the potential of HBPEs in preventing gastric and/or intestinal cancer should be further considered.

Characterization of Berry Pomace Powders as Dietary Fiber-Rich Food Ingredients with Functional Properties

This study aimed to evaluate and compare the dried pomace powder of cranberries, lingonberries, sea buckthorns, and black currants as potential food ingredients with functional properties. The composition and several physicochemical and adsorption properties associated with their functionality were investigated. Tested berry pomace powders were rich in dietary soluble fiber (4.92–12.74 g/100 g DM) and insoluble fiber (40.95–65.36 g/100 g DM). The highest level of total phenolics was observed in the black currant pomace (11.09 GAE/g DM), whereas the sea buckthorn pomace revealed the highest protein concentration (21.09 g/100 g DM). All the berry pomace powders that were tested exhibited good water-holding capacity (2.78–4.24 g/g) and swelling capacity (4.99–9.98 mL/g), and poor oil-binding capacity (1.09–1.57 g/g). The strongest hypoglycemic properties were observed for the lingonberry and black currant pomace powders. The berry pomace powders presented effective in vitro hypolipidemic properties. The cholesterol-binding capacities ranged from 21.11 to 23.13 mg/g. The black currant and cranberry pomace powders demonstrated higher sodium-cholate-binding capacity than those of the lingonberry and sea buckthorn pomace powders. This study shows promising results that the powders of tested berry pomace could be used for further application in foods.

Fruit Wastes as a Valuable Source of Value-Added Compounds: A Collaborative Perspective

The by-products/wastes from agro-food and in particular the fruit industry represents from one side an issue since they cannot be disposed as such for their impact on the environment but they need to be treated as a waste. However, on the other side, they are a source of bioactive healthy useful compounds which can be recovered and be the starting material for other products in the view of sustainability and a circular economy addressing the global goal of "zero waste" in the environment. An updated view of the state of art of the research on fruit wastes is here given under this perspective. The topic is defined as follows: (i) literature quantitative analysis of fruit waste/by-products, with particular regards to linkage with health; (ii) an updated view of conventional and innovative extraction procedures; (iii) high-value added compounds obtained from fruit waste and associated biological properties; (iv) fruit wastes presence and relevance in updated databases. Nowadays, the investigation of the main components and related bioactivities of fruit wastes is being continuously explored throughout integrated and multidisciplinary approaches towards the exploitation of emerging fields of application which may allow to create economic, environmental, and social value in the design of an eco-friendly approach of the fruit wastes.

Evaluation of some in vitro bioactivities of sunflower phenolic compounds

Phenolic compounds in crude extracts were obtained from defatted sunflower seed flour using sodium bisulfite and ethanol solutions as extracting agents. The antioxidant, antimicrobial, anti-proliferative, and DNA protective activities of the phenolic compounds in crude extract were analyzed. The phenolic compound contents were determined as chlorogenic acid (CGA) equivalent, presenting 11.57 and 15.44 g CGA eq/100g regarding the sodium bisulfite extract and ethanolic extract, respectively. The ORAC, DPPH, and ABTS methods were used to evaluate antioxidant activity. Both extracts presented antioxidant properties, considering that the ethanolic extract demonstrated higher values (EC₅₀ 0.36 g extract/g DPPH•). The antimicrobial action was analyzed as to the minimal inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC) of 4 kinds of bacteria (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis). The ethanolic extract was effective against all of these microorganisms, out of which E. coli was the most sensitive, with a MIC of 11.6 mg CGA/mL. The ethanolic extract presented DNA protective activity without cytotoxic activity concerning in vitro anti-proliferative assay. These findings can be considered as initial evidence of the potential use of phenolic compounds obtained from sunflower seed flour as natural additives in the food industry.

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Sunflower flour processing provides a phenolic extract as a byproduct.

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Sunflower phenolic extract exhibited antioxidant and antibacterial activity.

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Ethanolic sunflower phenolic extract exhibited DNA protection.

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Phenolic compounds extracts from sunflower has a potential as a food additive.

Ex Vivo Study on the Antioxidant Activity of a Winemaking By-Product Polyphenolic Extract (Taurisolo®) on Human Neutrophils

Oxidative stress (OxS) has been linked to several chronic diseases and is recognized to have both major causes and consequences. The use of antioxidant-based nutraceuticals has been licensed as an optimal tool for management of OxS-related diseases. Currently, great interest is focused on the valorization of agri-food by-products as a source of bioactive compounds, including polyphenols. In this sense, we evaluated the efficacy of a novel nutraceutical formulation based on polyphenolic extract from Aglianico cultivar grape pomace (registered as Taurisolo^®). In particular, we tested both native and in vitro gastrointestinal digested forms. The two extracts have been used to treat ex vivo neutrophils from subjects with metabolic syndrome, reporting a marked antioxidant activity of Taurisolo^®, as shown by its ability to significantly reduce both the levels of reactive oxygen species (ROS) and the activities of catalase and myeloperoxidase in the cell medium after stimulation of neutrophils with phorbol 12-myristate 13-acetate (PMA). Interestingly, we observed an increase in intracellular enzymatic activities in PMA-treated cells, suggesting that Taurisolo^® polyphenols might be able to activate nuclear factors, up-regulating the expression of this target antioxidant gene. In addition, Taurisolo^® reversed the increase in malondialdehyde induced by PMA; reduced the expression of pro-inflammatory genes such as cyclooxygenase 2 (COX-2), tumor necrosis factor alpha (TNFα) and myeloperoxidase (MPO); and induced the expression of the anti-inflammatory cytokine IL-10. Overall, these results suggest the efficacy of Taurisolo^® in contrasting the OxS at blood level, providing evidence for its therapeutic potential in the management of OxS-related pathological conditions in humans.

Hydrogel with silver nanoparticles synthesized by Mimosa tenuiflora for second-degree burns treatment

In this work we use Mimosa tenuiflora (MtE) extracts as reducing agents to synthesize silver nanoparticles (AgMt NPs) which were characterized by DPPH and Total Polyphenols Assays, UV-visible, X-ray diffractometer (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and Thermogravimetric analysis (TGA). AgMt NPs possess average sizes of 21 nm and fcc crystalline structure, it was also confirmed that the MtE is present in the AgMt NPs even after the cleaning protocol applied. Subsequently, carbopol hydrogels were made and the MtE and the synthesized AgMt NPs were dispersed in different gels (MtE-G and AgMt NPs-G, respectively) at 100 µg/g concentration. The gels were characterized by UV-Vis, IR, and rheology. Antimicrobial tests were performed using Staphylococcus aureus and Escherichia coli. Burn wound healing was evaluated in a second-degree burn injury on a Wistar rats model for 14 days and additional skin biopsies were examined with histopathological analysis. Gel with commercial silver nanoparticles (Ag NPs) was prepared and employed as a control on the biological assays. Hydrogel system containing silver nanoparticles synthesized with Mimosa tenuiflora (AgMt NPs-G) is a promising therapeutic strategy for burn wound healing, this due to bactericidal and anti-inflammatory effects, which promotes a more effective recovery (in percentage terms) by damaged area.

New trends in the use of enzymes for the recovery of polyphenols in grape byproducts

Residues from wine and juice processing still contain about 70% of the phenolic compounds in grapes. These compounds are valued for having several bioactive properties that are explored in the pharmaceutical and food sectors. This paper aims to summarize the most recent advances in the use of enzymatic techniques for the recovery of bioactive compounds from GP for industrial application. For this, we analyzed scientific articles and patent applications from the last 20 years in the main indexed and patent databases. Among the most used enzymes in the recovery of bioactive compounds in wastes, cellulases, pectinases, tannases, glucoamylases, and proteases such as trypsin and chymotrypsin, are the most important. As a result, extracts are obtained with greater retrieval of compounds such as anthocyanins, gallic acid, catechins, epicatechins, and trans-resveratrol and the improvement of coloring, anti-inflammatory, antioxidant and vasoprotective properties. Although the use of enzymes for the recovery of phenolics is an old strategy, the number of studies focusing on the functional characteristics and industrial applicability of the extracts obtained has been recently growing. PRACTICAL APPLICATIONS: Phenolic compounds have acted as anti-inflammatories, antioxidants, anticarcinogens, and antimicrobials, being additives or relevant ingredients for various products in the food and pharmaceutical industry. Although there are several techniques for extracting/recovering phenolics from grape pomace, there is still no agreement on which method is ideal. In recent years, several extractions methods have been applied in seeking optimized conditions to recover phenolics from grape residues. Among them, the use of enzymes has been gaining attention for being considered a green and promising technology. The present study aims to carry out a review that would bring a new perspective to the recovery of bioactive compounds from grape residues by enzymatic techniques, with a view to industrial purpose.

Do Flavonoids from Durum Wheat Contribute to Its Bioactive Properties? A Prospective Study

A clear gap with respect to the potential biological properties of wheat flavonoids exists in the available literature. This information is crucial for breeding programs aiming to produce new varieties presenting improved health benefits. Accordingly, advanced breeding lines of whole durum wheat were evaluated in this contribution. The highest recovery of phenolics was achieved using aqueous acetone (50:50, v/v), as verified by multi-response optimization, thus showing that phenolics could be largely underestimated by employing an inappropriate extraction. The concentration of derivatives of apigenin, the main phenolics present, ranged from 63.5 to 80.7%, as evaluated by LC-ESI-QTOF-MS. Phenolics from the breeding line 98 exhibited the highest ability in scavenging peroxyl radicals, reducing power as well as in terms of inhibition of pancreatic lipase activity, a key enzyme regulating the absorption of triacylglycerols. In contrast, none of the samples exhibited a significant anti-diabetic potential. Despite their high concentration compared to that of phenolic acids, results of this work do not support a significant antioxidant and pancreatic lipase inhibitory effect of durum wheat flavonoids. Therefore, breeding programs and animal and/or human trials related to the effect of durum wheat flavonoids on oxidative stress and absorption of triacylglycerols are discouraged at this point.

Effect of Caesalpinia bonduc Polyphenol Extract on Alloxan-Induced Diabetic Rats in Attenuating Hyperglycemia by Upregulating Insulin Secretion and Inhibiting JNK Signaling Pathway

Caesalpinia bonduc has been used in herbal medicines for the treatment of a wide range of diseases from decades. The present study has explored the remedial potential and underlying mechanism of polyphenol extract of Caesalpinia bonduc in alloxanized diabetic rats. HPLC/MS analysis confirmed the presence of phenolics in considerable concentrations in Caesalpinia bonduc extract. Administration of different doses (250 and 500 mg/kg) of CPP extract to hyperglycemic rats for 8 weeks restored blood and serum glucose, insulin, glycosylated hemoglobin, leptin, amylin, and carbohydrate metabolizing enzymes level towards normal compared to alloxanized diabetic group. The effect of CPP extract on various genes such as Pdx-1, Ins-1, ngn-3, GLUT-4, and IRS-1 in insulin signaling pathway and Traf-4, Traf-6, and Mapk-8 in MAPK downstream JNK cascade was examined through qRT-PCR to access the core molecular mechanism involved in CPP-induced recovery of diabetes. Results have revealed that CPP extract reduced oxidative stress in pancreatic β cells by restoring free radical scavenging potential, reducing the mRNA expression of Mapk-8, Traf-4, and Traf-6, and increasing the Pdx-1, Ins-1, ngn-3, GLUT-4, and IRS-1 expression ensuing regeneration of β cells and subsequent insulin release from pancreas. The results obtained in this study recommend that CPP extract may be a promising therapeutic restorative agent in the treatment of diabetes mellitus.

Protective effects of beet (Beta vulgaris) leaves extract against oxidative stress in endothelial cells in vitro

Beetroot is an herb used worldwide as a food product, raw material for food industry, ethanol production and source of food coloring. Beet leaves are an unconventional food with antioxidant properties, which might neutralize reactive oxygen species (ROS) induced by oxidized Low-Density Lipoprotein (LDL) present in dyslipidemias. This study aimed to elucidate the effects of beet leaves on the suppression of LDL oxidative processes. Beet leaves extract was produced, characterized, and tested for its antioxidant capacity using endothelial cells in vitro. A model of human umbilical vein endothelial cells was used in various tests, including viability assay, molecular analysis of antioxidant genes, ROS labeling, and macrophage adhesion assay. The extract improved the antioxidative protection of endothelial cells against different agents including oxidized LDL-cholesterol and H₂ O₂ . It acted on ROS directly due to its high content of natural antioxidants, but also due to the activation and improvement of cellular defenses such as Superoxide dismutase 1, Superoxide dismutase 2, and catalase. The inhibition of LDL-mediated oxidative effects on endothelial cells may turn this unconventional food a functional food with great potential for phytotherapy of atherosclerosis as an adjuvant for medicinal treatments.

Mainly Dimers and Trimers of Chinese Bayberry Leaves Proanthocyanidins (BLPs) are Utilized by Gut Microbiota: In Vitro Digestion and Fermentation Coupled with Caco-2 Transportation

Chinese bayberry leaf proanthocyanidins (BLPs) are Epigallocatechin gallate (EGCG) oligomers or polymers, which have a lot of health-promoting activity. The activity is closely related to their behavior during in vitro digestion, which remains unknown and hinders further investigations. To clarify the changes of BLPs during gastrointestinal digestion, further research is required. For in vitro digestion, including gastric-intestinal digestion, colon fermentation was applied. Caco-2 monolayer transportation was also applied to investigate the behavior of different BLPs with different degrees of polymerization. The trimers and the tetramers were significantly decreased during in vitro gastric-intestinal digestion resulting in a significant increase in the content of dimers. The dimers and trimers were the main compounds utilized by gut microbiota and they were assumed not to degrade through cleavage of the inflavan bond. The monomers and dimers were able to transport through the Caco-2 monolayer at a rate of 10.45% and 6.4%, respectively.

Combination of Lactobacillus plantarum and Saccharomyces cerevisiae DV10 as Starter Culture to Produce Mango Slurry: Microbiological, Chemical Parameters and Antioxidant Activity

The aim of this study was to develop a nondairy fermented product based on mango slurry. Lactobacillus plantarum and Saccharomyces cerevisiae DV10 were used as starter cultures in single and co-cultivations. The microbial populations and metabolites produced during mango slurry fermentation were investigated. At the end of all fermentations, the bacterial populations were higher than 6.0 log CFU/mL. Lactic acid was the main organic acid produced, achieving up to 6.12 g/L after 24 h in co-culture with L. plantarum and S. cerevisiae DV10. Volatile compounds were determined after 24 h of fermentation, the co-cultures of L. plantarum and S. cerevisiae DV10 could decrease terpenes and produce alcohols and esters. The co-cultivations obtained the most total phenolics as well as showed the strongest 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical scavenging activity, ferric-reducing antioxidant power (FRAP) and low-density lipoprotein (LDL) oxidation inhibition. Hence, a high-bioactivity probiotic product was successfully obtained via mango slurry fermentation inoculated with a co-culture of L. plantarum and S. cerevisiae DV10.

Optimizing the potential bioactivity of isoflavones from soybeans via ultrasound pretreatment: Antioxidant potential and NF-κB activation

Soybean consumption has been associated with health benefits. However, the effect of ultrasound (US) soybean pretreatment in terms of potential health benefits has not been investigated so far. Accordingly, the total phenolic content (TPC) and the total aglycone content (TAC) were optimized using the Box-Behnken design. Contrasting samples regarding isoflavones aglycones and TPCs were screened for their antioxidant and anti-inflammatory potentials using RAW 264.7 macrophages. US pretreated soybeans (55°C, 15 min, and 24 W/cm2 ) showed greater TPC and TAC compared to the control and this translated to higher antiradical activity and reduction of nuclear factor kappa B (NF-κB) activation. The concentration of genistein in treated soybeans increased by 95%. Furthermore, US pretreated soybeans rendered phenolic extracts that reduced the NF-κB activation by 86%. Therefore, this contribution demonstrates the beneficial effects of US pretreatment of soybeans, which provides a better feedstock for the functional food industry. PRACTICAL APPLICATIONS: Soybeans can be consumed as such or used as a feedstock to produce soy yogurt, fermented soymilk, tofu, and protein concentrate, among others. The greatest bioavailability of isoflavones compared to other flavonoids has recently been highlighted, and this has been explained by the relatively moderate lipophilicity of isoflavones as aglycones. The present contribution supports the use of US pretreatment of soybeans to obtain a feedstock with improved contents of isoflavones as aglycones. We have confirmed that phenolic extracts obtained from the US pretreated samples showed higher bioactivity as radical scavengers and by reducing the activation of nuclear factor kappa B (NF-κB) in a cell model, which is mediated by oxidative species. The clinical importance of NF-κB activation is derived mainly from its role in inflammatory responses. Therefore, our investigation may have a practical application in the procurement of soybean products and/or ingredients with improved functional properties related to their health benefits.

Synthesis of Gold Nanoparticles Using Mimosa tenuiflora Extract, Assessments of Cytotoxicity, Cellular Uptake, and Catalysis

Synthesis of gold nanoparticles (AuNPs) with plant extracts has gained great interest in the field of biomedicine due to its wide variety of health applications. In the present work, AuNPs were synthesized with Mimosa tenuiflora (Mt) bark extract at different metallic precursor concentrations. Mt extract was obtained by mixing the tree bark in ethanol-water. The antioxidant capacity of extract was evaluated using 2,2-diphenyl-1-picrylhydrazyl and total polyphenol assay. AuNPs were characterized by transmission electron microscopy, X-ray diffraction, UV-Vis and Fourier transform infrared spectroscopy, and X-ray photoelectron spectrometry for functional group determination onto their surface. AuMt (colloids formed by AuNPs and molecules of Mt) exhibit multiple shapes with sizes between 20 and 200 nm. AuMt were tested on methylene blue degradation in homogeneous catalysis adding sodium borohydride. The smallest NPs (AuMt1) have a degradation coefficient of 0.008/s and reach 50% degradation in 190s. Cell viability and cytotoxicity were evaluated in human umbilical vein endothelial cells (HUVEC), and a moderate cytotoxic effect at 24 and 48 h was found. However, toxicity does not behave in a dose-dependent manner. Cellular internalization of AuMt on HUVEC cells was analyzed by confocal laser scanning microscopy. For AuMt1, it can be observed that the material is dispersed into the cytoplasm, while in AuMt2, the material is concentrated in the nuclear periphery.

Identification and Characterization of Major Constituents in Different-Colored Rapeseed Petals by UPLC-HESI-MS/MS

Oilseed rape (Brassica napus L.) is the second highest yielding oil crop worldwide. In addition to being used as an edible oil and a feed for livestock, rapeseed has high ornamental value. In this study, we identified and characterized the main floral major constituents, including phenolic acids and flavonoids components, in rapeseed accessions with different-colored petals. A total of 144 constituents were identified using ultrahigh-performance liquid chromatography-HESI-mass spectrometry (UPLC-HESI-MS/MS), 57 of which were confirmed and quantified using known standards and mainly contained phenolic acids, flavonoids, and glucosinolates compounds. Most of the epicatechin, quercetin, and isorhamnetin derivates were found in red and pink petals of B. napus, while kaempferol derivates were in yellow and pale white petals. Moreover, petal-specific compounds, including a putative hydroxycinnamic acid derivative, sinapoyl malate, 1-O-sinapoyl-β-d-glucose, feruloyl glucose, naringenin-7-O-glucoside, cyanidin-3-glucoside, cyanidin-3,5-di-O-glucoside, petunidin-3-O-β-glucopyranoside, isorhamnetin-3-O-glucoside, kaempferol-3-O-glucoside-7-O-glucoside, quercetin-3,4'-O-di-β-glucopyranoside, quercetin-3-O-glucoside, and delphinidin-3-O-glucoside, might contribute to a variety of petal colors in B. napus. In addition, bound phenolics were tentatively identified and contained three abundant compounds (p-coumaric acid, ferulic acid, and 8-O-4'-diferulic acid). These results provide insight into the molecular mechanisms underlying petal color and suggest strategies for breeding rapeseed with a specific petal color in the future.

Analysis by UPLC-DAD-ESI-MS of Phenolic Compounds and HPLC-DAD-Based Determination of Carotenoids in Noni ( Morinda citrifolia L.) Bagasse

Noni bagasse is usually wasted after the noni juice extraction process. The purpose of this study was to investigate the phytochemical composition of noni bagasse (with and without seeds) obtained after a 1 week period of a short-term juice drip-extraction process from over-ripe noni fruit. Totals of free phenolics, flavonoids, condensed tannins, carotenoids, and most of the minerals were higher in bagasse without seeds (NSB) than in bagasse with seeds (WSB), whereas bound phenolics and total and insoluble dietary fiber were higher in WSB than in NSB. β-Carotene and lutein, quantified by HPLC-DAD, were higher in both bagasse than in juice. A total of 16 phenolic compounds and 2 iridoids were determined by UPLC-DAD-ESI-MS. Among them, procyanidin B-type dimer, caffeoylquinic-acid-hexoside, and quercetin-hexose-deoxyhexose have not been previously reported in noni bagasse, noni juice, or noni fruit. Isorhamnetin-3- O-rutinoside was the most abundant compound in both bagasses. In conclusion, both bagasses are potential sources of phytochemical compounds for the food and pharmaceutical industries.

Is Chickpea a Potential Substitute for Soybean? Phenolic Bioactives and Potential Health Benefits

Legume seeds are rich sources of protein, fiber, and minerals. In addition, their phenolic compounds as secondary metabolites render health benefits beyond basic nutrition. Lowering apolipoprotein B secretion from HepG2 cells and decreasing the level of low-density lipoprotein (LDL)-cholesterol oxidation are mechanisms related to the prevention of cardiovascular diseases (CVD). Likewise, low-level chronic inflammation and related disorders of the immune system are clinical predictors of cardiovascular pathology. Furthermore, DNA-damage signaling and repair are crucial pathways to the etiology of human cancers. Along CVD and cancer, the prevalence of obesity and diabetes is constantly increasing. Screening the ability of polyphenols in inactivating digestive enzymes is a good option in pre-clinical studies. In addition, in vivo studies support the role of polyphenols in the prevention and/or management of diabetes and obesity. Soybean, a well-recognized source of phenolic isoflavones, exerts health benefits by decreasing oxidative stress and inflammation related to the above-mentioned chronic ailments. Similar to soybeans, chickpeas are good sources of nutrients and phenolic compounds, especially isoflavones. This review summarizes the potential of chickpea as a substitute for soybean in terms of health beneficial outcomes. Therefore, this contribution may guide the industry in manufacturing functional foods and/or ingredients by using an undervalued feedstock.

Whole flour and protein hydrolysate from common beans reduce the inflammation in BALB/c mice fed with high fat high cholesterol diet

Common bean (Phaseolus vulgaris L.) is a source of bioactive peptides, but little is known about its effects on hypercholesterolemia, oxidative stress, and the inflammatory process. Therefore, the aim of this study was to evaluate the effect of whole flour and bean protein hydrolysate of common bean variety Carioca on inflammation and oxidative stress in BALB/c mice. Four experimental groups were included in the study: standard diet (SD), high fat high cholesterol diet (HFC), high fat high cholesterol diet and whole bean flour (HFC-F); and high fat high cholesterol diet and bean protein hydrolysate (HFC-PH). Animals fed with bean protein hydrolysate showed lower weight gain and food intake. Animals fed with whole bean flour showed lower alanine aminotransferase and low-density lipoprotein cholesterol levels than animals fed with bean protein hydrolysate. SOD mRNA was lower in HFC, HFC-F and HFC-PH groups whereas SOD concentration was higher in HFC-F and HFC-PH groups. HSP72 mRNA expression was lower in the HFC-F group in relation to HFC-PH. IL-10 and PPARα mRNA expression was lower in HFC-F and HFC-PH groups in comparison with SD. The whole bean flour and bean protein hydrolysate reduced inflammation and the risk factors for cardiovascular diseases in BALB/c mice.

Should we ban total phenolics and antioxidant screening methods? The link between antioxidant potential and activation of NF-κB using phenolic compounds from grape by-products

Free radical imbalance is associated with several chronic diseases. However, recent controversies have put in check the validity of colorimetric methods to screen the functionality of polyphenols. Therefore, in this study two antioxidant methods, based on chemical reactions, were tested for their ability in anticipating the reduction of the activation of NF-κB using LPS-activated RAW 264.7 macrophages, selected as a biological model. Grape processing by-products from winemaking showed higher total phenolic content (TPC), antioxidant capacity towards peroxyl radical (31.1%) as well as reducing power (39.5%) than those of grape juice by-products. The same trend was observed when these samples were tested against LPS-activated RAW 264.7 macrophages by reducing the activation NF-κB. Feedstocks containing higher TPC and corresponding ORAC and FRAP results translated to higher reduction in the activation of NF-κB (36.5%). Therefore, this contribution demonstrates that colorimetric methods are still important screening tools owing their simplicity and widespread application.

Pomegranate juice and extract extended lifespan and reduced intestinal fat deposition in Caenorhabditis elegans

Pomegranate juice with a high content of polyphenols, pomegranate extract, ellagic acid, and urolithin A, have anti-oxidant and anti-obesity effects in humans. Pomegranate juice extends lifespan of Drosophila melanogaster. Caenorhabditis elegans (C. elegans) (n = 6) compared to the control group in each treatment, lifespan was increased by pomegranate juice in wild type (N2, 56 %, P < 0.001) and daf-16 mutant (daf-16(mgDf50)I) (18 %, P = 0.00012), by pomegranate extract in N2 (28 %, P = 0.00004) and in daf-16(mgDf50)I (10 %, P < 0.05), or by ellagic acid (11 %, P < 0.05). Pomegranate juice reduced intestinal fat deposition (IFD) in C. elegans (n = 10) N2 (-68 %, P = 0.0003) or in the daf-16(mgDf50)I (-33 %, P = 0.0034). The intestinal fat deposition was increased by pomegranate extract in N2 (137 %, P < 0.0138) and in daf-16(mgDf50)I (26 %, P = 0.0225), by ellagic acid in N2 (66 %, P < 0.0001) and in daf-16(mgDf50)I (74 %, P < 0.0001), or by urolithin A in N2 (57 %, P = 0.0039) and in daf-16(mgDf50)I (43 %, P = 0.0001). These effects were partially mediated by the daf-16 pathway. The data may offer insights to human aging and obesity due to homology with C. elegans.

In vitro digestion of meat- and cereal-based food matrix enriched with grape extracts: How are polyphenol composition, bioaccessibility and antioxidant activity affected?

The aim of this study was to evaluate the effect of enriching a complex food matrix (FM) with grape extracts on polyphenol content, composition, bioaccessibility and antioxidant activity during digestion. The grape extracts and FM were separately tested under the same conditions as controls. The FM by itself contains a significant amount of phenolic acids and flavonols, influencing the final recovery of polyphenols from grape extracts. The FM significantly increased the total recovery of polyphenols after digestion of grape seed extracts compared to those digested without the FM; however, a low recovery of proantocyanidins and total flavonoids was observed. Digestive fluids and FM compounds significantly increased the total polyphenol content of grape digests and significantly contributed to their ABTS⁺ scavenging activity and ferrous-ion-chelating capacity. The present study suggested that enrichment of meat- and cereal-based products with grape polyphenol extracts could be a good strategy to formulate a healthier diet.

Opinion on the Hurdles and Potential Health Benefits in Value-Added Use of Plant Food Processing By-Products as Sources of Phenolic Compounds

Plant foods, their products and processing by-products are well recognized as important sources of phenolic compounds. Recent studies in this field have demonstrated that food processing by-products are often richer sources of bioactive compounds as compared with their original feedstock. However, their final application as a source of nutraceuticals and bioactives requires addressing certain hurdles and challenges. This review discusses recent knowledge advances in the use of plant food processing by-products as sources of phenolic compounds with special attention to the role of genetics on the distribution and biosynthesis of plant phenolics, as well as their profiling and screening, potential health benefits, and safety issues. The potentialities in health improvement from food phenolics in animal models and in humans is well substantiated, however, considering the emerging market of plant food by-products as potential sources of phenolic bioactives, more research in humans is deemed necessary.

Evaluation of secondary metabolites, antioxidant activity, and color parameters of Nepali wines

We evaluated the quality of wines produced in Nepal in terms of phenolic, flavonoid, anthocyanin and tannin content, antioxidant capacity, and color parameters using spectrophotometric methods. The total phenolic content, total flavonoid content, and total antioxidant activities in Nepali wines ranged from 85.5 to 960.0 (mean = 360.5 ± 268.7) mg/L GAE, 40.9-551.3 (mean = 188.9 ± 161.5) mg/L QE, and 66.6-905.0 (mean = 332.8 ± 296.5) mg/L AAE, respectively. These parameters were significantly higher in red wines compared to white wines. The phenolic and flavonoid content showed strong correlation with each other as well as with antioxidant activities. Additional parameters measured included various color parameters and carbohydrates. The wine color showed strong correlation with phenol, flavonoid, and antioxidant activity, whereas this correlation was not significant with anthocyanin content. Multivariate analysis was carried out to better describe and discriminate the wine samples. Finally, we compared Nepali wines with wines from other countries.

Beneficial Effects of Tomato Juice Fermented by Lactobacillus Plantarum and Lactobacillus Casei: Antioxidation, Antimicrobial Effect, and Volatile Profiles

Tomato juice was fermented by Lactobacillus plantarum and Lactobacillus casei to produce an innovative high-bioactivity probiotic beverage. The levels of lycopene, total carotenoids, ascorbic acid, total phenolic and volatile compounds, 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azinobis-3-ethylbenzotiazo-line-6-sulfonic acid (ABTS) radical scavenging capacities, ferric reducing antioxidant power (FRAP), and Escherichia coli flora, as well as the inhibition of copper-induced human low-density lipoproteins (LDL)-cholesterol oxidation assays, were measured. The results revealed that the ABTS and DPPH inhibition values, as well as the FRAP and total phenolic content, were significantly increased. LDL-cholesterol oxidation was markedly delayed after the addition of the fermented juice. The in vitro inhibitory effects of Escherichia coli flora were substantially increased after being fermented with Lactobacillus plantarum and Lactobacillus casei. The results associated with the volatile compounds indicated that fermentation with Lactobacillus plantarum and Lactobacillus casei is a meaningful strategy for modifying flavors.

Metal Chelating, Inhibitory DNA Damage, and Anti-Inflammatory Activities of Phenolics from Rambutan (Nephelium lappaceum) Peel and the Quantifications of Geraniin and Corilagin

Whereas the preparation and biological properties of rambutan peel phenolics (RPP) were explored in our previous studies, the metal chelating, inhibitory DNA damage, and anti-inflammatory activities of RPP were evaluated and the important phenolics of RPP quantified in this study. Results showed that RPP had high Fe²⁺ and Cu²⁺-chelating activities with EC₅₀ of 0.80 mg/mL and 0.13 mg/mL, respectively. RPP effectively decreased the production of hydroxyl radical with IC₅₀ of 62.4 μg/mL. The protective effects of RPP against AAPH-induced DNA damage were also explored. RPP efficiently inhibited peroxyl radical-induced plasmid DNA strand breakage. The anti-inflammatory effects of RPP were determined using a lipopolysaccharide (LPS)-induced RAW 264.7 cell model. RPP significantly inhibited the production of nitric oxide (NO) and controlled the levels of inducible NO synthase mRNA in LPS-induced RAW 264.7 cells. The inhibitory activity increased in a dose-dependent manner. The above bioactivity of RPP was associated with its phenolic content and phenolic profiles. Furthermore, the contents of geraniin and corilagin in RPP were determined by an ultra-high performance liquid chromatography coupled with triple quadruple mass spectrometry (UPLC-QQQ-MS), showing 140.02 and 7.87 mg/g extract dry weight. Thus, RPP has potential applications as a novel nutraceutical and functional food in health promotion.

Improving the quality of matured coconut (Cocos nucifera Linn.) water by low alcoholic fermentation with Saccharomyces cerevisiae: antioxidant and volatile profiles

Matured coconut water (MCW) is a by-product in the coconut milk industry that is usually discarded due to its unpleasant flavor. In this study, low-alcohol coconut water (LACW) was fermented with Saccharomyces cerevisiae to improve the quality of MCW. Volatile components and nonvolatile flavor-related elements were estimated to compare the qualities of the MCW and LACW. Besides measuring the kinetic changes, the levels of fructose, glucose, sucrose and ethanol contents were also determined. The results of the organic acid assays showed that tartaric, pyruvic and succinic acids were the primary organic acids present in LACW and increased significantly with fermentation. The resulting volatile composition assay indicated that esters, alcohols and fatty acids were significantly influenced by fermentation and yeast strains. Moreover, 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), cupric ion reducing antioxidant capacity and ferric reducing antioxidant power values increased significantly throughout the process, correlating with the enhancement of total phenolic content.