Profile Of Phenolic Compounds Research Articles

Discrimination and characterization of different coconut water (CW) by their phenolic composition and volatile organic compounds (VOCs) using LC-MS/MS, HS-SPME-GC-MS, and HS-GC-IMS.

Three varieties of coconut (Cocos nucifera L.) water (CW) at two maturity stages were investigated for physicochemical and nutritional properties. The profile of phenolic compounds and volatile organic compounds (VOCs) was determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS), headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS), and headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS). Most of the properties of CW changed significantly with maturity rather than variety. The five most relevant phenolic compounds in CW were chlorogenic acid, 4-hydroxy-3,5-dimethoxycinnamic acid, L-epicatechin, and procyanidins B2 and B1. Variety played a more important role in phenolic composition than maturity, and Wenye No. 4 can be distinguished from other two varieties. Alcohols and esters were the main VOCs in CW identified by HS-GC-IMS and HS-SPME-GC-MS, respectively. Five and four compounds (VIP scores>1) were characteristic compounds for CW by HS-GC-IMS and HS-SPME-GC-MS, respectively. The VOCs of Wenye Nos. 2 and 3 were more similar than those of Wenye No. 4. These findings could provide useful information for the selection of raw materials of CW used for different industrial purposes.

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.

Mineral composition, the profile of phenolic compounds, organic acids, sugar and in vitro antioxidant capacity, and antimicrobial activity of organic extracts of Juniperus drupacea fruits.

Juniperus drupacea fruit is widely used in traditional and complementary medicine in Turkey for the treatment of different diseases in various forms such as molasses and tar. This study was carried out to evaluate the phenolic compounds, organic acid, sugar, and macro- and micromineral distributions of methanol and water extracts of J. drupace fruit, as well as their antioxidant and antimicrobial potential. For this purpose, total phenolic content by spectrophotometer, phenolics, organic acids, and sugars distributions by HPLC in extracts of J. drupacea fruits, and macro- and micromineral element content by ICP-AES in fruit were determined. 2,2-diphenyl-l-picrylhydrazyl assay (DPPH assay) was used to evaluate in vitro antioxidant activity in extracts. The antimicrobial potential of J. drupacea fruit methanol extract against some gram-positive and gram-negative pathogenic bacteria was evaluated using disk diffusion and minimum inhibitory concentration (MIC) methods. The potassium macroelement and the iron microelement were found at high content in J. drupacea fruit. The total phenolic content in the methanol extracts was higher than the water extracts. Among the individual phenolic compounds, catechin, a flavonoid that was the highest in both extractions, was determined as 300.49 μg/g in methanol extract and 314.88 μg/g in water extract. DPPH scavenging activity was higher in methanol extracts. While the methanol extract of J. drupacea had no-inhibitory effect on the gram-negative bacteria tested, it exhibited a strong inhibition on the gram-positive bacteria Listeria innocua, Listeria monocytogenes, Staphylococcus carnosus, and Enterococcus faecalis.

Comparison of phenolic profiles of albino bilberry (Vaccinium myrtillus L.) wines fermented by non-Saccharomyces yeasts

The profiles of phenolic compounds in albino bilberry (Vaccinium myrtillus L.) juice and wines fermented with eight different non-Saccharomyces yeasts, including Torulaspora (Tr.) delbrueckii, Issatchenkia (Is.) orientalis, Lachancea (Lc.) thermotolerans, Saccharomycodes (Sd.) ludwigii, Hanseniaspora (Hs.) uvarum, Metschnikowia (Mt.) pulcherrima, Pachysolen (Pc.) tannophilus, and Schizosaccharomyces (Sz.) pombe, were assessed using UHPLC-QTOF-MS and UHPLC-DAD. A total of 40 phenolic compounds, including 20 phenolic acids, 16 flavonols, and 4 flavan-3-ols, were identified and quantified in the albino bilberry products. In unfermented juice, phenolic acids were the most predominant group, accounting for 80.5% of total phenolics. After fermentation, the concentrations of phenolic acids, flavonols, and flavan-3-ols showed significant increases by 21.8%–42.5%, 26.8%–47.2%, and 4.9%–74.5%, respectively. Five new flavonols including myricetin-3-O-glucoside, kaempferol-3-O-galactoside, laricitrin-3-O-galactoside, isorhamnetin-3-O-galactoside, and syringetin aglycone, which were absent in the albino bilberry juice, were formed during fermentation mainly by the metabolism of non-Saccharomyces yeasts. The phenolic compositions of albino bilberry wines depended primarily on the applied yeasts. Most of the non-Saccharomyces yeasts showed positive contributions to the increase of phenolic compounds except for Pc. tannophilus PT70352, which reduced the total phenolic content reflecting the decreases in concentrations of phenolic acids and flavan-3-ols, especially of p-coumaroyl monotropeins, procyanidin B-type dimers, and (−)-epicatechin. The highest levels of phenolic acids and flavan-3-ols were detected in the sample fermented by Hs. uvarum HU26650. The fermentations with Sd. ludwigii SL3447, Tr. delbrueckii TD291, and Mt. pulcherrima MP70321 were characterized by higher concentrations of myricetin-3-O-glucoside and syringetin-3-O-glucoside but lower contents of most phenolic acids.

Chemical Characterization, Bioactivity and Toxicity of European Flora Plant Extracts in Search for Potential Natural Origin Preservatives.

Consumer demand for natural and healthier products has led to an increasing interest in the bioactive and therapeutic properties of plant extracts. In this study, we evaluated the phenolic compounds profile, bioactivities, and toxicities of plant extracts from eight European flora species, including Calendula officinalis L., Calluna vulgaris (L.) Hull, Hippophae rhamnoides L., Juglans regia L., Mentha cervina L., Rubus idaeus L., Sambucus nigra L., and Vitis vinifera L. The aim was to identify potential preservatives of natural origin. Phenolic compounds were identified by HPLC-DAD-ESI-MS. Caffeic acid derivatives, ellagitannins, flavonols, and flavones were the major phenolic compounds identified. The total phenolic content varied from 16.0 ± 0.2 (V. vinifera) to 123 ± 2 mg/g (H. rhamnoides) of dry extract. All extracts showed antioxidant potential and exhibited activity against some of the microorganisms tested. S. nigra showed the highest activity in the inhibition of oxidative hemolysis (OxHLIA) assay and H. rhamnoides, notably, had the lowest IC50 values in TBARS and DPPH assays, as well as the lowest minimum inhibitory concentration (MIC) values. Regarding in vitro cytotoxicity, in tumor and non-tumor cell lines, although some extracts revealed toxicity against normal cells, it was found that the samples C. vulgaris, V. vinifera and R. idaeus might be used against tumor cells since the active concentration is much lower than the one causing toxicity. In vivo acute toxicity tests using Artemia franciscana suggest low toxicity for most extracts, with LC50 > 400 mg/L. These results showed the potential of the studied extracts as natural preservatives, given their richness in compounds with bioactive properties, highlight their potential value to the production chain.

Optimization of pH for extracting sinapates from mustard varieties using green technology

Mustard seeds contain higher levels of phenolic compounds, especially sinapine, compared to many other oilseeds. Due to their rich bioactive composition, mustard seeds have considerable potential in food and pharmaceutical industries as antimicrobials, antioxidants, and chemoprotective agents. The yields of phenolic compounds, particularly the formation of canolol, could be substantially enhanced by modifying the pre-treatment conditions and extraction techniques. To achieve this, there is a need for innovative green technology methods to minimize environmental damage. This novel approach involved pre-heating by sautéing, and adjusting the pH of the extract to acid, alkaline or neutral conditions using safe household ingredients, such as vinegar and sodium bicarbonate. The treated whole or crushed seeds were then extracted by pressurized heating at 115 °C at 10.2 psi, and the extractability of the phenolic compounds was assessed.Statistical analysis of selected mustard varieties showed an interesting trend in which pH affected the mustard endogenous phenolic compound profile, in which neutral pH proved to be superior to acid and alkaline treatment Among the selected varieties, both yellow and black mustard had competitive amounts of sinapine, sinapic acid, and canolol. Sinapic acid and canolol were predominant in crushed black mustard seeds (2.71± 0.0.8 and 2.61± 0.35 mg/g DW, respectively) (p < 0.05). Meanwhile, crushed yellow mustard prevailed in sinapine concentration (385 ± 49.47 mg/g DW).Overall, on the basis of electrostatic interactions between the solvent and the extractants, using water with the combination of preheat treatment and pressure was an alternative green extraction method to optimize the extraction of phenolic compounds from Oriental, black, and yellow mustard seeds.

Monofloral Corn Poppy Bee-Collected Pollen-A Detailed Insight into Its Phytochemical Composition and Antioxidant Properties.

The aim of this study was to compile a detailed phytochemical profile and assess the antioxidant properties of bee-collected pollen (PBP) obtained from corn poppy (Papaver rhoeas L.) plants. To achieve this, a lipid fraction was prepared for quantifying fatty acids using GC-FID. Extractable and alkaline-hydrolysable PBP fractions (obtained from a defatted sample) were used to determine the qualitative and quantitative profiles of phenolic compounds, phenylamides and alkaloids using UHPLC/Q-ToF-MS. Additionally, various spectrophotometric assays (TAC, FRP, CUPRAC, DPPH⦁) were conducted to evaluate the antioxidant properties. Phenolic compounds were more present in the extractable fraction than in the alkaline-hydrolysable fraction. Luteolin was the predominant compound in the extractable fraction, followed by tricetin and various derivatives of kaempferol. This study presents one of the first reports on the quantification of tricetin aglycone outside the Myrtaceae plant family. The alkaline-hydrolysable fraction exhibited a different phenolic profile, with a significantly lower amount of phenolics. Kaempferol/derivatives, specific compounds like ferulic and 5-carboxyvanillic acids, and (epi)catechin 3-O-gallate were the predominant compounds in this fraction. Regarding phenylamides, the extractable fraction demonstrated a diverse range of these bioactive compounds, with a notable abundance of different spermine derivatives. In contrast, the hydrolysable fraction contained six spermine derivatives and one spermidine derivative. The examined fractions also revealed the presence of seventeen different alkaloids, belonging to the benzylisoquinoline, berberine and isoquinoline classes. The fatty-acid profile confirmed the prevalence of unsaturated fatty acids. Furthermore, both fractions exhibited significant antioxidant activity, with the extractable fraction showing particularly high activity. Among the assays conducted, the CUPRAC assay highlighted the exceptional ability of PBP's bioactive compounds to reduce cupric ions.

Effects of winemaking techniques on the phenolics, organic acids, and volatile compounds of Muscat wines

This study aimed to investigate the impact of various winemaking techniques on the phenolic, organic acid and aroma compound profiles, as well as sensory characteristics of different Muscat wines including dry white wine (DWW), orange wine (OW), rose wine (RW), semi-sweet wine (SW), sweet white wine (SWW), 3% vol wine (3%W), 5% vol wine (5%W), 7% vol wine (7%W), fortified wine (FW) and distilled wine(DW). A total of 14 individual phenolics, 11 organic acids were performed by HPLC and 33 volatile compounds were determined by GC-MS. The highest contents of individual phenolics, organic acids, and aroma compounds were found in DWW, SWW, and SW, respectively, while DW contained the lowest quantities. Sensory analysis showed that 7%W and SWW performed well in terms of overall quality. This study laid a foundation for optimizing the process of winemaking so that the wine products meet the needs of consumers by retaining the characteristics of rose aroma grape varieties.

Profile of phenolic compounds and antioxidant activity of organically and conventionally grown black-grain barley genotypes treated with biostimulant.

Beneficial dietary and pro-health values, have resulted in the increasing consumption importance of barley. Therefore, genotypes and cultivation methods are sought that guarantee high functional value of grain. The aim of the study was to assess the content of phenolic acids, flavonoids, chlorophylls, anthocyanidins, phytomelanin and antioxidant activity of grain of three barley genotypes depending on agricultural technology. Two of them are primary genotypes with dark grain pigmentation Hordeum vulgare L. var nigricans and H. vulgare L. var. rimpaui, the third is a modern cultivar 'Soldo' H. vulgare with yellow grain, which is the control sample. Evaluated the effect of foliar application of a amino-acids biostimulant on the functional properties of grain under the conditions of organically and conventionally cultivations. The results indicated a higher antioxidant activity and the concentration of phenolic acids, flavonoids and phytomelanin in the black-grain genotypes. Organic cultivation and application of amino acids had increased the content of phenolic compounds in grain. The antioxidant activity was correlated with the content of syringic acid, naringenin, quercetin, luteolin and phytomelanin. Organically cultivation and the foliar application of an amino acid biostimulant improved the functional properties of barley grain, in particular the original, black-grained genotypes.

Myrtaceae leaves grown in Agroforestry: a sustainable alternative to producing natural antioxidants extracts

Myrtaceae species such as uvaia, grumixama, and feijoa have been used in Brazil’s Agroforestry Systems (AFS). In AFS, frequent pruning occurs, and leaves are discarded. However, the leaves contain specific phenolic compounds (PC) that, when appropriately extracted, produce extracts with antioxidant activity (AA). These extracts meet the demand for natural and sustainable food ingredients. Therefore, the drying study (40, 50, and 60 °C) of uvaia, grumixama, and feijoa leaves obtained from AFS was carried out, and the effect of drying on the PC profile (LC-ESI-MS/MS) and AA were evaluated. In the uvaia extracts, the major compounds were EGCG, gallic acid, and isoquercitin, accounting for 94% of their PC, and leaves dried at 50 °C promoted a better phenolic extraction. The gallic acid, 2.5 DHBA and isoqueticitrin represent 79% of the relative composition of PC in grumixama extracts, and leaves dried at 60 °C were the condition that allowed a greater extraction. While, epicatechin, catechin, gallic acid and isoquercitrin correspond to 66% of the PC composition of feijoa leaves. Grumixama had the highest values for AA by the FCRC and DPPH while feijoa had significant values for FRAP in all treatments. Dried leaves at 50 °C showed higher AA for all methods, except for grumixama which showed this behavior at 60 °C. These results indicate that these matrices proved promising sustainable sources of various phenolic compounds. The drying process of the leaves at 50 and 60 °C had a greater extraction of compounds with antioxidant activity, with potential industrial applications.

Role of the Green Husks of Persian Walnut (Juglans regia L.)—A Review

Green husks are the outer layer of walnut fruits. They form part of the agro-residues discarded away upon nut maturity in the walnut industry. Although it is not used, research studies show that green husk is a rich source of natural bioactive phytochemicals. A total of 83 individual phenolic compounds were identified in walnut husks, mainly consisting of naphthoquinones, flavonols, and hydroxycinnamic acids. There is no standard profile of phenolic compounds in walnuts; the quantity and quality of phenolic compounds vary by cultivar. Walnut extracts exhibit strong antioxidant activities and play an important role in the plant’s defence mechanisms against diseases, attacking different plant organs. The study provides a review of total phenolic content and individual phenolic compounds identified in green husks of different walnut cultivars as documented in different studies. It also explores the role and application of green husks in various industries such as traditional medicine, textile, wood, leather, beverage, and agriculture. In addition, the effects of phenolic compounds on biotic and abiotic factors are also evaluated.

Green Assessment of Phenolic Acid Composition and Antioxidant Capacity of Advanced Potato Mutant Lines through UPLC-qTOF-MS/MS Quantification.

Potatoes are one of the most consumed crops worldwide. They contain a high amount of bioactive compounds such as phenolic compounds and vitamins with important antioxidant activities, which makes this crop of high biological value for human health. The goal of this research was to biochemically evaluate polyphenol levels and antioxidant capacities in parent and control genotypes compared to advanced mutant potato lines in the M1V8 generation. This will reveal the genetic changes that result from induced mutagenesis. The quantified compounds and the evaluated antioxidant activity boost the health benefits of consuming the improved mutant potatoes. In the present study, the phenolic composition and antioxidant activity of eighteen mutant and initial potato genotypes were analyzed by UPLC-qTOF-MS/MS and the ORAC method, respectively. In each of the hybrid combinations, mutant lines with an improved phenolic compound profile were observed. Representative samples from the third hybrid combination had notable increases in phenolic compound concentrations, as well as the presence of metabolites not found in the parental lines. With one exception, the remaining nine mutants showed significantly higher antioxidant capacities. The results will be used in future potato breeding programs, with participation of the valuable mutant lines containing new phenolic substances not present in the initial genotypes.

Elevated nutrient supply can exert worse effects on Norway spruce than drought, viewed through chemical defence against needle rust.

Abiotic factors such as water and nutrient availability can exert a dominant influence on the susceptibility of plants to various pathogens. Effects of abiotic environmental factors on phenolic compound concentrations in the plant tissue may represent one of the major underlying mechanisms, as these compounds are known to play a substantial role in plant resistance to pests. In particular, this applies to conifer trees, in which a large range of phenolic compounds are produced constitutively and/or induced by pathogen attack. We subjected Norway spruce saplings to water limitation and elevated nutrient supply over two years and subsequently controlled infection with the needle rust Chrysomyxa rhododendri and analysed both constitutive and inducible phenolic compound concentrations in the needles as well as the degree of infection. Compared to the control group, both drought and fertilization profoundly modified the constitutive and pathogen induced profiles of phenolic compounds, but had little impact on the total phenolic content. Fertilization predominantly affected the inducible phenolic response and led to higher infection rates by C. rhododendri. Drought stress, in contrast, mainly shaped the phenolic profiles in healthy plant parts and had no consequences on the plant susceptibility. The results show that specific abiotic effects on individual compounds seem to be decisive for the infection success of C. rhododendri, whereby the impaired induced response in saplings subjected to nutrient supplementation was most critical. Although drought effects were minor, they varied depending on the time and length of water limitation. The results indicate that prolonged drought periods in the future may not significantly alter the foliar defence of Norway spruce against C. rhododendri, but fertilization, often propagated to increase tree growth and forest productivity, can be counterproductive in areas with high pathogen pressure.

Microencapsulation of phenolic compounds from cashew apple (Anacardium occidentale L.) agro-food waste: Physicochemical characterization, antioxidant activity, biodisponibility and stability

In the present study was evaluated the microencapsulation of cashew apple waste hydroalcoholic extracts rich in bioactive compounds by spray drying using maltodextrin and inulin as encapsulating agents. The maximum total phenolic content (TPC = 668.25 mg GAE 100 g−1) was extracted using 60% of grain ethanol acidified with 2.0% of citric acid. An encapsulating efficiency (68.38%) and retention of phenolic compounds (51.48%) with moderate antioxidant activities were observed using a mixture of maltodextrin (75%) and inulin (25%). The spray-dried microparticles presented a spherical shape without roughness, thus contributing to maintain the stability of the microencapsulated food ingredient. The microparticles obtained was submitted to in vitro digestion and after this process was observed a retention of 61.85% and 48.65% of TPC and ABTS radical scavenging activity, respectively. Moreover, a high recovery (RI = 102.4%) and suitable bioacessibily (BI = 52.32%) also observed. The stability storage of microparticles was evaluated during 60-days in terms of physicochemical parameters, powder properties, antioxidant activity, profile of phenolic compounds and organic acids, being observed suitable maintenance of phenolic content during the storage. The results obtained indicates bioactive-rich microparticles obtained is an interesting alternative for utilization as ingredient for enrichment of food products and nutraceutical formulas.

Protective Role of Phenolic Compounds from Whole Cardamom (Elettaria cardamomum (L.) Maton) against LPS-Induced Inflammation in Colon and Macrophage Cells.

The chemical profiling of phenolic and terpenoid compounds in whole cardamom, skin, and seeds (Elettaria cardamomum (L.) Maton) showed 11 phenolics and 16 terpenoids, many of which are reported for the first time. Herein, we report the anti-inflammatory properties of a methanolic extract of whole cardamom in colon and macrophage cells stimulated with an inflammatory bacteria lipopolysaccharide (LPS). The results show that cardamom extracts lowered the expression of pro-inflammatory genes NFkβ, TNFα, IL-6, and COX2 in colon cells by reducing reactive oxygen species (ROS) while not affecting LXRα. In macrophages, cardamom extracts lowered the expression of pro-inflammatory genes NFkβ, TNFα, IL-6, and COX2 and decreased NO levels through a reduction in ROS and enhanced gene expression of nuclear receptors LXRα and PPARγ. The cardamom extracts in a range of 200-800 μg/mL did not show toxicity effects in colon or macrophage cells. The whole-cardamom methanolic extracts contained high levels of phenolics compounds (e.g., protocatechuic acid, caffeic acid, syringic acid, and 5-O-caffeoylquinic acid, among others) and are likely responsible for the anti-inflammatory and multifunctional effects observed in this study. The generated information suggests that cardamom may play a protective role against low-grade inflammation that can be the basis of future in vivo studies using mice models of inflammation and associated chronic diseases.

Phenolic compounds profile and antioxidant activity of purple passion fruit's pulp, peel and seed at different maturation stages

The purple passion fruit (Passiflora edulis Sims) is a fruit that has an intense and wrinkled purple peel when ripe. In the food industry, the passion fruit pulp is used in the production of juices and nectars, while the peel and seeds are considered waste, although they have great biotechnological potential due to their chemical composition, with emphasis on bioactive compounds. In this study, the profile of 13 phenolics, two alkaloids, the total phenolic content and the antioxidant activity, evaluated by different methods, of the pulp, peel and seed of purple passion fruit at three maturation stages, were evaluated. Fifteen metabolites in the phenolic and alkaloid profile were identified in the different fractions of the fruit, and by their variation, processes of synthesis and degradation along ripening were suggested. As for the content of phenolic compounds and antioxidant activity, the seed stood out compared to the peel and pulp. The results obtained suggest the health benefits of consuming the fruit pulp, and the potential for using the peel and seed as by-products that are also beneficial to health and as candidates for biotechnological use in industries and research centers.

Characterization of Antioxidant and Antimicrobial Activity and Phenolic Compound Profile of Extracts from Seeds of Different Vitis Species.

Seeds of Vitis vinifera L. with a high content of bioactive compounds are valuable by-products from grape processing. However, little is known about the bioactivity of seeds from other Vitis species. The aim of this study has been to compare the phenolic composition, antimicrobial activity, and antioxidant activity of extracts from seeds of four Vitis species (V. riparia Michx., V. californica Benth., V. amurensis Rupr., and V. vinifera L.). Antioxidant activities were assessed as ferric-reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) scavenging activity, and oxygen radical absorbance capacity (ORAC). The antimicrobial activity was determined using the microdilution method against some Gram-negative (Escherichia coli, Salmonella enterica ser. Typhimurium, and Enterobacter aerogenes) and Gram-positive (Enterococcus faecalis and Staphylococcus aureus) bacteria. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to evaluate the phenolic profile of extracts. Flavan-3-ols, procyanidins, phenolic acids, flavonols, anthocyanins, and stilbenoids were detected. (+)-Catechin and (-)-epicatechin turned out to be the most abundant in the phenolic profile of V. amurensis seed extract. Phenolic acids prevailed in the extract from V. vinifera seeds. The V. riparia and V. californica seed extracts had higher contents of most individual phenolics compared to the other Vitis species. They also showed a higher total phenolic content, DPPH• scavenging activity, ORAC, and overall antibacterial activity. Total phenolic content significantly correlated with antioxidant activity and antimicrobial activity against E. coli. The principal component analysis (PCA) showed discrimination between V. vinifera, V. amurensis, and clustered V. riparia and V. californica with respect to variables. To recapitulate, this research demonstrates that seeds of different Vitis species, especially V. riparia and V. californica, are sources of molecules with antioxidant and antimicrobial activities that can be used in different sectors, such as in the food, cosmetic, and pharmaceutical industries.

Physicochemical Aspects, Bioactive Compounds, Phenolic Profile and In Vitro Antioxidant Activity of Tropical Red Fruits and Their Blend.

The combination of fruit pulps from different species, in addition to multiplying the offer of flavors, aromas and textures, favors the nutritional spectrum and the diversity of bioactive principles. The objective was to evaluate and compare the physicochemical characteristics, bioactive compounds, profile of phenolic compounds and in vitro antioxidant activity of pulps of three species of tropical red fruits (acerola, guava and pitanga) and of the blend produced from the combination. The pulps showed significant values of bioactive compounds, with emphasis on acerola, which had the highest levels in all parameters, except for lycopene, with the highest content in pitanga pulp. Nineteen phenolic compounds were identified, being phenolic acids, flavanols, anthocyanin and stilbene; of these, eighteen were quantified in acerola, nine in guava, twelve in pitanga and fourteen in the blend. The blend combined positive characteristics conferred by the individual pulps, with low pH favorable for conservation, high levels of total soluble solids and sugars, greater diversity of phenolic compounds and antioxidant activity close to that of acerola pulp. Pearson's correlation between antioxidant activity and ascorbic acid content, total phenolic compounds, flavonoids, anthocyanins and carotenoids for the samples were positive, indicating their use as a source of bioactive compounds.

Comparative Methods to Evaluate the Antioxidant Capacity of Propolis: An Attempt to Explain the Differences.

Propolis is a natural product produced by bees that contains a complex mixture of compounds, including phenolic compounds and flavonoids. These compounds contribute to its biological activities, such as antioxidant capacity. This study analysed the pollen profile, total phenolic content (TPC), antioxidant properties, and phenolic compound profile of four propolis samples from Portugal. The total phenolic compounds in the samples were determined by six different techniques: four different Folin-Ciocalteu (F-C) methods, spectrophotometry (SPECT), and voltammetry (SWV). Of the six methods, SPECT allowed the highest quantification, while SWV achieved the lowest. The mean TPC values for these methods were 422 ± 98 and 47 ± 11 mg GAE/g sample, respectively. Antioxidant capacity was determined by four different methods: DPPH, FRAP, original ferrocyanide (OFec), and modified ferrocyanide (MFec). The MFec method gave the highest antioxidant capacity for all samples, followed by the DPPH method. The study also investigated the correlation between TPC and antioxidant capacity with the presence of hydroxybenzoic acid (HBA), hydroxycinnamic acid (HCA), and flavonoids (FLAV) in propolis samples. The results showed that the concentrations of specific compounds in propolis samples can significantly impact their antioxidant capacity and TPC quantification. Analysis of the profile of phenolic compounds by the UHPLC-DAD-ESI-MS technique identified chrysin, caffeic acid isoprenyl ester, pinocembrin, galangin, pinobanksin-3-O-acetate, and caffeic acid phenyl ester as the major compounds in the four propolis samples. In conclusion, this study shows the importance of the choice of method for determining TPC and antioxidant activity in samples and the contribution of HBA and HCA content to their quantification.

Green synthesis of Ag/Ag2O nanoparticles on cellulose paper and cotton fabric using Eucalyptus globulus leaf extracts: Toward the clarification of formation mechanism

The present study reports on phenolic compounds profile of Eucalyptus globulus leaf extracts and exhibiting their role in obtaining silver nanoparticles (AgNP) by a green method on paper and fabric supports with or without addition of NaOH. To know the mechanism involved in the formation of AgNP, FTIR, UV–Visible spectrophotometry and UHPLC-QTOF-MS analyzes were carried out of E. globulus extracts before and after the synthesis of AgNP. The FTIR, UV–Visible spectrophotometry analyzes identified phenolic compounds, and to a lesser extent reducing sugars mainly participate as reducing agents in the formation of AgNP, while phenolic compounds would participate as stabilizing agents. UHPLC-QTOF-MS analyzes identified derived from gallic acid play an important role in AgNP formation. AgNPs were characterized in their morphology and structure by SEM-EDS, TEM-SAED, XRD, UV–Vis diffuse reflectance and TGA. The results indicate the formation of Ag and/or Ag2O nanoparticles depending on the influence of NaOH in the reaction system. Furthermore, the support used (paper or fabric), it would influence the concentration of AgNPs formed, the consumption of phenolic compounds, the antibacterial activity and band-gap of AgNPs synthesized. This study provides evidence of a simple process to support AgNP on cellulose and providing key information towards the definitive clarification of the mechanism of formation of AgNP by green synthesis.