Analysis Of Phenolic Composition Research Articles

Physical Traits and Phenolic Compound Diversity in Maize Accessions with Blue-Purple Grain (Zea mays L.) of Mexican Races

Consumer interest in foods enriched with phytochemical compounds for health benefits has prompted plant breeders to focus on developing new cultivars with an enhanced content of specific compounds. Studies regarding the exploration of germplasms of species of great economic importance, such as maize, could be useful in this task. This study aimed to assess the physical grain traits and phenolic compound variations (including anthocyanins, flavonoids, and proanthocyanidins) in blue-purple maize accessions from various Mexican races. We examined 207 accessions from 21 Mexican maize races, evaluating physical grain traits such as weight of one hundred grains (W100G), endosperm type (ET), pigment location, and grain color. Phenolic composition analysis encompassed total soluble phenolics (TSP), total anthocyanin content (TAC), flavonoids (FLAV), and proanthocyanidins (PAs). The predominant endosperm type was floury, with W100G values indicating a large grain size and the pigment primarily located in the aleurone layer. Among phenolic composition variables, only TSP exhibited a normal distribution, while others skewed towards the left side. A hierarchical analysis of phenolic composition data revealed three distinct groups comprising different numbers of Mexican varieties, with TAC proving the most effective for grouping. Our comprehensive exploration of maize diversity featuring blue-purple grain coloration has led to the identification of novel maize varieties with outstanding phenolic contents.

Yield and biochemical fruit quality of irrigated peach cultivars subjected to conventional farmer’s fertilization practices in warm production area

Water and fertilization management are the main concerns of farmers in order to achieve an economic yield and high fruit quality. This study evaluates conventional farmer’s fertilization practices in commercial peach orchards (Regueb region) and sets suitable nitrogen (N), phosphorus (P), and potassium (K) supplies to improve yield and fruit quality. Different farmers’ N-P-K supply practices (called FarmNPK) were applied during the different developmental stages of the growing season (S1 budburst and swelling; S2 flowering and fruit set; S3 fruit development; and S4 fruit ripening). Seven cultivars (Flordastar, Plagold5, Plagold10, Plagold15, Plawhite5, Plawhite10, and UFO3) were considered. Depending on cultivars and growth stage, the ranges of total N-P-K supplies were 95–208, 44–84, and 67–103 kg ha−1, respectively. Total fresh yield was quantified, and fruit quality (pomology, phenolic composition, main sugars, and organic acids) was determined in the mesocarp and exocarp. The results revealed that NPK supplies from 95–65–76 to 165–84–103 kg ha−1 induced the highest yield that varied between 50 and 68 kg tree−1, especially with high N supplies during S2. In all cultivars, high N and K supplies in S3 and S4 induced the best weight and fruit size, with the highest total soluble solid content in the fruit, while P supply appeared to be negatively correlated with total sugar content. Analysis of phenolic composition showed that flavan-3-ols varied between 209 and 7114 mg kg−1 DW. In conclusion, the optimum supply of N, P, and K at the appropriate stages, mainly S2 for N supply, and S3 and S4 improved color and ensured appreciable quality.

Exploring the synergistic potential of wild nettle and olive oil: bioactive compounds, antioxidant capacity, and antibacterial properties

ABSTRACT This study delved into the incorporation of wild nettle (Urtica dioica L.) leaves powder with virgin olive oil, exploring its potential to enhance nutritional value and health benefits. The antioxidant, antibacterial, and mineral-enrichment attributes of the resultant nettle-infused olive oil were investigated. Phenolic composition analysis revealed that an optimal maceration time of 30–40 minutes leads to maximal phenolic and flavonoid contents (57.66 mg GAE/100 g and 67.18 mg QE/100 g, respectively). The infused oil demonstrated superior radical scavenging activity (DPPH and ABTS assays) compared to virgin olive oil. Notably, nettle infusion significantly elevates zinc (10.12 mg/kg) and iron (13.85 mg/kg) contents. Antibacterial assays exhibited enhanced inhibition diameters and lower MIC and MBC values for nettle-infused oil against various bacterial strains. The study’s findings underscore the potential of nettle infusion to enhance the nutritional and functional attributes of olive oil, holding promise for novel culinary and health applications.

HPLC-PDA/ESI-MS Analysis of Phenolic Compounds and Bioactivities of the Ethanolic Extract from Flowers of Moroccan Anacyclus clavatus.

In this work, polyphenols were extracted from Anacylus clavatus flowers using a hydroethanolic solvent, and the obtained extract was studied for its total phenol and flavonoid contents and evaluated for its antioxidant and antibacterial capacities. The contents of total phenols and flavonoids were measured by employing gallic acid and quercetin as references, respectively, and the phenolic composition analysis was conducted using high-performance liquid chromatography combined with a photodiode array and electrospray ionization mass spectrometry (HPLC-PDA/ESI-MS). The antioxidant capacity of the extracts was tested using a potassium ferric reducing antioxidant power (PFRAP) assay, and the antibacterial activity assay was carried out against Gram-negative bacteria (Escherichia coli and Salmonella typhimirium) and Gram-positive bacteria (Staphyloccocus aureus and Listeria monocytogenes) using the broth microdilution assay. The phenolic and flavonoid contents of the extracts equaled 9.53 ± 0.48 mg GAE/g dm and 1.31 ± 0.06 mg QE/g dm, respectively. The chromatographic analysis of the phenolic profile detected 26 phenolic compounds belonging to phenolic acids, flavones and flavonols, and with the caffeoylquinic acid derivatives being the major phenolic compounds present in 12 isomers. Only one organic compound, viz. citric acid, was found. The extracts exhibited interesting antioxidant activity. Bacteriostatic activity towards Escherichia coli and bactericidal activity against Salmonella typhimirium, Staphyloccocus aureus and Listeria monocytogenes were determined. This study revealed that Anacyclus clavatus flower extracts contain phenolic compounds with interesting bioactivities.

Comprehensive analysis of polyphenols from hybrid Mandarin peels by SPE and HPLC-UV

Polyphenol compounds are the most important bioactive components in citrus peels. An efficient clean-up method based on solid-phase extraction with C18 cartridges (SPE-C18) and high-performance liquid chromatography, coupled with ultraviolet detector (HPLC-UV) determination, was set up for the analysis of phenolic composition in ultrasound assisted extraction from hybrid mandarin (Citrus reticulata) peels (Clemenvilla, Nadorcott, Ortanique). The SPE-C18/HPLC-UV method was validated according to linearity (R2 ≥ 0.998), good precision (intra-day and inter-day), relative standard deviations (<5% in most cases), low limits of detection and quantitation, adequate recovery, and low matrix effect. Eight flavonoids and seven phenolic acids were separated and determined in a single chromatographic run. Ultra-high-performance liquid chromatography, coupled with quadrupole-time-of-flight-mass spectrometry (UPLC-qTOF-MS/MS), was used to confirm the polyphenols previously detected. Results showed that hesperidin and narirutin were the most abundant phenolic compounds in the three hybrid mandarin peel extracts. This study describes an affordable, suitable method for identifying and quantifying phenolic compounds in hybrid mandarin peels. The correlation and analysis of the principal components also showed the main differences between the varieties analysed. There were clear differences between Clemenvilla and Nadorcott and Ortanique, due to the significantly lower narirutin concentration (P < 0.05) in the case of Clemenvilla.

Authentication of honey of different nectar sources and antioxidant property evaluation by phenolic composition analysis with chemometrics

The chemometric second-order multivariate calibration method was applied to the qualitative and quantitative analysis of seven phenolic acids in honey samples with five different floral origins. First, based on the “second-order advantage,” reasonable resolutions and satisfactory quantitative results were obtained even in the presence of strong background interference and overlapping peaks in complex real honey samples. Average spike recoveries for the seven target analytes were in the range of 89.34–118.81%, with high correlation coefficient (r ≥ 0.9997), low limit of quantification (1.00–20.20 ng mL−1) and high sensitivity (0.135–0.375 mL ng−1). Second, the quantitative data of seven target analytes were analyzed by principal component analysis (PCA) on MATLAB software to classify honey of five nectar sources. These results indicated that there is a strong association between the content of major phenolic acids and the flower sources of honey. Third, the quantitative composition-antioxidant activity relationship analysis was evaluated by partial least squares (PLS) analysis and studied to provide reliable analysis of multi-marker antioxidant data. The results enable the continued exploitation and utilization of honey from different floral origins and further contribute to honey market development and choices in available honey for consumption.

HPLC-DAD-Q-ToF-MS profiling of phenolic compounds from mango (Mangifera indica L.) seed kernel of different cultivars and maturation stages as a preliminary approach to determine functional and nutraceutical value

Mango seed kernel is a by-product which is usually discarded. However, it has been confirmed in this study that seed kernel exhibits more phenolic compounds with bioactive properties than edible fraction of mango. The influence of factors such as cultivar and maturation degree on the phenolic composition has been studied to evaluate nutraceutical value. The comprehensive analysis of phenolic composition by HPLC-DAD-Q-ToF-MS seed kernel from different cultivars (‘Keitt’, ‘Kent’and ‘Osteen’) at five maturation stages was conducted. Results evidenced that ‘Keitt’ samples exhibited higher quantities of iriflophenone glucoside, maclurin C-glucoside, maclurin digalloyl glucoside, mangiferin, 5-galloyl quinic acid and trigalloyl glucose at the first three ripening stages. However, seed kernel from ‘Osteen’ variety showed higher amounts of hexa- and hepta-gallotannins whose concentrations diminished over the maturation course. Therefore, cultivar and maturation stage factors should be take into account due to their influence on the phenolic composition and subsequently on the nutraceutical value.

Alcoholic fermentation as a potential tool for coffee pulp detoxification and reuse: Analysis of phenolic composition and caffeine content by HPLC-DAD-MS/MS

High-performance liquid chromatography with diode array (HPLC-DAD) and liquid chromatograph triple quadrupole mass spectrometry (HPLC-MS/MS) were used to characterize raw and fermented coffee pulps in terms of their phenolic composition and caffeine content. The qualitative analysis showed no significant differences between the raw and the fermented pulps. Free hydroxycinnamic acids (HAs) were mainly chlorogenic acids, with 5-caffeoylquinic acid as the major compound. Bound HAs released caffeic acids during alkaline hydrolysis, and no bound ferulic and p-coumaric acids were detected. The fermentation process allowed the detoxification of the pulp from caffeine by 50%, while significantly reducing the amounts of residue by 64%. Moreover, the fermented products could be further processed to provide high added-value molecules with potential industrial applications, providing a new source of income for the small coffee producers.

Analysis of Phenolic Composition of Byproducts (Seeds and Peels) of Avocado (Persea americana Mill.) Cultivated in Colombia.

The byproducts (seeds and peels) of an avocado cultivated in the south of Colombia were extracted with aqueous acetone and their antioxidant properties were measured with ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) assays, and total polyphenol content was determined by Folin–Ciocalteu method. A bioguided fractionation was performed, first by SPE (solid phase extraction) on Amberlite XAD-7, and then by size exclusion chromatography on Sephadex LH-20. The polyphenolic-rich extracts and their fractions were analyzed by ultra-performance liquid chromatography–electrospray ionization–mass spectrometry (UPLC-ESI-MS/MS), finding the presence of organic acids, hydroxycinnamic acids, catechins, free and glycosylated flavonoids, and dimeric and trimeric procyanidins. Catechin, epicatechin, six quercetin derivatives, four dimeric procyanidins (three type B and one type A), and three trimeric procyanidins (two type B and one type A) were detected in the most active fractions of avocado peel and seeds. The most antioxidant fractions contain the higher molecular weight phenolic compounds (condensed tannins).

Yak-Kong Soybean (Glycine max) Fermented by a Novel Pediococcus pentosaceus Inhibits the Oxidative Stress-Induced Monocyte–Endothelial Cell Adhesion

Yak-Kong (YK), a small black soybean (Glycine max) in Korea, contained higher concentrations of antioxidants than ordinary black soybean or yellow soybean in our previous study. We prepared the fermented YK extract by using a novel lactic acid bacterium, Pediococcus pentosaceus AOA2017 (AOA2017) isolated from Eleusine coracana, and found that the antioxidant ability was enhanced after fermentation. In order to investigate the cause of the enhanced antioxidant ability in the fermented YK extract, we conducted a phenolic composition analysis. The results show that proanthocyanidin decreased and phenolic acids increased with a statistical significance after fermentation. Among the phenolic acids, p-coumaric acid was newly produced at about 11.7 mg/100 g, which did not exist before the fermentation. Further, the fermented YK extract with increased p-coumaric acid significantly inhibited the lipopolysaccharide-induced THP-1 monocyte–endothelial cell adhesion compared to the unfermented YK extract. The fermented YK extract also suppressed the protein expression levels of vascular cell adhesion molecule (VCAM)-1 in human umbilical vein endothelial cells (HUVECs). Together with the previous studies, our results suggest that the extract of YK fermented by AOA2017 has potential to be a new functional food material with its enhanced bioactive compounds which may help to prevent atherosclerosis caused by oxidative stress.

Comprehensive phenolic composition analysis and evaluation of Yak-Kong soybean (Glycine max) for the prevention of atherosclerosis

Yak-Kong (YK) (Glycine max), a small black soybean cultivar with a green embryo, was evaluated for functional constituents with a focus on atherosclerosis prevention. In comparison to common yellow and black soybean cultivars, YK contains significantly higher concentrations of antioxidants, particularly in its seed coat. A comprehensive phenolic composition analysis revealed that proanthocyanidins were the major phenolic group in YK. In contrast to other proanthocyanidin-rich foods, YK was rich in bioavailable proanthocyanidins (with a degree of polymerization ≤3) specifically with A-type dimers. Significant concentrations of phloridzin and coumestrol were also exclusively found in YK seed coat and the embryo, respectively. Extracts of both the proanthocyanidin-rich seed coat and isoflavonoid-rich embryo of YK attenuated adhesion of THP-1 to LPS-stimulated human umbilical vascular endothelial cells, suggesting that they are important sources of coronary heart disease-preventive phenolics. YK has promising potential for further development as a functional food source targeted at atherosclerosis prevention.

Combined ANFIS and numerical methods to simulate ultrasound-assisted extraction of phenolics from chokeberry cultivated in China and analysis of phenolic composition

Abstract A 20-kHz ultrasound was utilized to extract phenolics from chokeberry cultivated in China using both distilled water and 50% aqueous ethanol as solvents. Sonication was performed at different acoustic energy density and temperature levels. Adaptive neuro-fuzzy inference system (ANFIS) was successful in correlating the operation parameters during extraction with total phenolic yield with the value of determination of coefficient higher than 0.97. In the constructed ANFIS model, “Gaussmf” was selected as the input membership function. Meanwhile, diffusion model was solved numerically to model the mass transfer process during sonication and identify the effective diffusivity of total phenolics. Generally, both AED and temperature had positive influences on the effective diffusivity of total phenolics. Furthermore, according to the analysis of high resolution mass spectrometry and high performance liquid chromatography, delphinidin-3- O -rutinoside, protocatechuic acid, chlorogenic acid and rutin had considerably high amounts in this Chinese chokeberry cultivar. In addition, through analyzing the phenolic composition in extracts, it was found that distilled water was an effective solvent for the extraction of some anthocyanins from chokeberry including cyanidin-3- O -glucoside, cyanidin-3- O -rutinoside and delphinidin-3- O -rutinoside, while sonication using 50% aqueous ethanol as solvent led to high recovery of phenolic acids and flavonols.

Phytochemical characterization and antioxidant potential of rustyback fern (Asplenium ceterach L.)

Asplenium ceterach (syn. Ceterach officinarum Willd.) or rustyback fern, is a plant species traditionally used in Mediterranean countries as expectorant, diuretic, against spleen complaints, kidney stones and hemorrhoids. Phytochemical analysis of gametophytes and sporophytes of A. ceterach was performed, followed by comparative analysis of phenolic composition and the antioxidant properties of the extracts (scavenging capacities against ABTS · + and DPPH · ). Totally 16 phenolic compounds belonging to the classes of phenolic acids (hydroxybenzoic and hydroxycynnamic acids), flavonoids (flavan-3-ols, flavonols), and xanthones were identified using UHPLC/DAD/–HESI-MS/MS analysis. Differential phenolics’ composition of the two phases of the life cycle of this fern was observed which significantly determined their radical scavenging activities. In sporophytes of A. ceterach considerably high amounts of chlorogenic acid were found, while xanthones were mostly abundant in gametophytes, recommending this fern species as a valuable source of bioactive compounds.

Antioxidant and antimicrobial activity of natural phenolic extract from defatted soybean flour by‐product for stone fruit postharvest application

Fresh fruit is highly perishable during storage and transport, so there has been growing interest in finding safe and natural antimicrobial compounds as a control tool. Phenolic compounds are secondary metabolites naturally present in vegetable material and have been associated with antimicrobial and antioxidant properties. Therefore, the aim of this study was to investigate the antioxidant capacity and potential antimicrobial effect of phenolic extract obtained from defatted soybean flour against selected pathogenic bacteria and microorganisms responsible of fruit decay. Analysis of phenolic composition by HPLC-MS showed the presence of a wide range of compounds, with isoflavones and phenolic acids the main polyphenols identified. Furthermore, the phenolic extract had important antioxidant activity by two different assays. Related to antimicrobial activity, in vitro experiments demonstrated that phenolic extract displayed a high activity against the main foodborne pathogens, while a moderate inhibition was found against five spoilage yeasts and Monilia laxa and a scarce effect for Penicillium glabrum, Cladosporium uredinicola and Botrytis cinerea. Interestingly these compounds considerably inhibited the mycelial growth of Monilia laxa, in both in vitro and in vivo experiments. The results of the present study revealed that defatted soybean flour is an important source of phenolic compounds with remarkable antimicrobial and antioxidant activity, suggesting the possibility of using them as natural additives in postharvest treatments to extend the shelf life of fruit.

Berry fruit teas: Phenolic composition and cytotoxic activity

A detailed phenolic composition analysis of dry chokeberry, bilberry and black currant fruit teas prepared on the most common ways — decoction and infusion, was performed, together with evaluation of cytotoxic activity. The most abundant in phenolics were chokeberry teas, followed by bilberry and black currant teas, while the highest anthocyanin amount was determined in bilberry samples. LC/DAD/MS method was used for identification of 17 anthocyanins, 11 flavonoids and 4 hydroxycinnamic acid derivatives. Quantitative analysis of investigated teas was carried out by HPLC analysis, and major phenolic compounds in berry fruit teas were chlorogenic acids, quercetin glycosides and anthocyanin glycosides. Berry teas were investigated for cytotoxic activity against cervix carcinoma, melanoma, colon, and chronic myelogenous leukemia cell lines, and chokeberry decoction was the most effective against all cell lines. According to the results obtained in this study, pure chokeberry, bilberry and black currant teas could be valuable sources of flavonoids and anthocyanins.

Bioactivity and phenolic composition from natural fermented table olives.

In the present work, the phenolic composition, and antioxidant and antimicrobial properties of twenty-four samples of naturally fermented table olives from the northeast of Portugal were evaluated. The analysis of phenolic composition was performed by HPLC/DAD, and ten compounds were identified, hydroxytyrosol, verbascoside derivate and hydroxytyrosol glycol being the most abundant. Total phenolic content varied between 2.37 and 64.17 μg mg(-1) of extract. The IC50 values from the antioxidant activity methods tested varied between 0.30 and 1.66 mg mL(-1) for reducing power, and between 0.13 and 0.83 mg mL(-1) for DPPH. The results obtained in the antioxidant activity were extremely significantly correlated with the main phenolic compounds as well as with the total phenolic content. A principal component analysis allowed grouping the samples according to their phenolic composition and antioxidant potential. Table olive extracts were able to inhibit some pathogenic microorganisms, mainly Gram-positive bacteria. Higher antimicrobial inhibition was recorded in the extracts rich in phenolic compounds and higher antioxidant potential.

Phenolic Composition Analysis and Gene Expression in Developing Seeds of Yellow‐ and Black‐seeded Brassica napus

Breeders have focused on yellow-seeded Brassica napus (rapeseed) for its better quality compared with the black-seeded variety. Moreover, flavonoids have been associated with this kind of rapeseed. In this study, we applied lipid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS(n)) to compare flavonoids in developing seeds of natural black-seeded B. napus and yellow-seeded introgression lines selected from progenies of B. napus-Sinapis alba somatic hybrids. Aside from the most abundant phenolic compounds (sinapine and sinapic acid) and 1, 2-disinapoylglucose, 16 different flavonoids were identified and quantified, including (-)-epicatechin, five monocharged oligomers of (-)-epicatechin ([DP 2](-), [DP 3](-), [DP 4] [DP 2](-) B2 and [DP 2](-) B5), quercetin, kaempferol, isorhamnetin-dihexoside, kaempferol-sinapoyl-trihexoside, isorhamnetin-sinapoyl-trihexoside, isorhamnetin-hexoside-sulfate, and isorhamnetin-3-O-glucoside. Most of the flavonoids accumulated with seed development, whereas some rapidly decreased during maturation. The content of these flavonoids were lower in the yellow-seeded materials than in the black seeds. In addition, variations of insoluble procyanidin oligomers and soluble phenolic acids were observed among both rapeseed varieties. Transcriptome changes of genes participating in the flavonoid pathway were discovered by quantitative reverse transcription polymerase chain reaction analysis. Consistent with flavonoid changes identified by high performance liquid chromatography analysis, the expression of most genes in the flavonoid biosynthetic pathway was also downregulated.

Antibacterial, antioxidant and tyrosinase-inhibition activities of pomegranate fruit peel methanolic extract.

BackgroundThis study evaluated, using in vitro assays, the antibacterial, antioxidant, and tyrosinase-inhibition activities of methanolic extracts from peels of seven commercially grown pomegranate cultivars.MethodsAntibacterial activity was tested on Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli and Klebsiella pneumonia) using a microdilution method. Several potential antioxidant activities, including radical-scavenging ability (RSA), ferrous ion chelating (FIC) and ferric ion reducing antioxidant power (FRAP), were evaluated. Tyrosinase enzyme inhibition was investigated against monophenolase (tyrosine) and diphenolase (DOPA), with arbutin and kojic acid as positive controls. Furthermore, phenolic contents including total flavonoid content (TFC), gallotannin content (GTC) and total anthocyanin content (TAC) were determined using colourimetric methods. HPLC-ESI/MSn analysis of phenolic composition of methanolic extracts was also performed.ResultsMethanolic peel extracts showed strong broad-spectrum activity against Gram-positive and Gram-negative bacteria, with the minimum inhibitory concentrations (MIC) ranging from 0.2 to 0.78 mg/ml. At the highest concentration tested (1000 μg/ml), radical scavenging activities were significantly higher in Arakta (83.54%), Ganesh (83.56%), and Ruby (83.34%) cultivars (P< 0.05). Dose dependent FIC and FRAP activities were exhibited by all the peel extracts. All extracts also exhibited high inhibition (>50%) against monophenolase and diphenolase activities at the highest screening concentration. The most active peel extract was the Bhagwa cultivar against monophenolase and the Arakta cultivar against diphenolase with IC50 values of 3.66 μg/ml and 15.88 μg/ml, respectively. High amounts of phenolic compounds were found in peel extracts with the highest and lowest total phenolic contents of 295.5 (Ganesh) and 179.3 mg/g dry extract (Molla de Elche), respectively. Catechin, epicatechin, ellagic acid and gallic acid were found in all cultivars, of which ellagic acid was the most abundant comprising of more than 50% of total phenolic compounds detected in each cultivar.ConclusionsThe present study showed that the tested pomegranate peels exhibited strong antibacterial, antioxidant and tyrosinase-inhibition activities. These results suggest that pomegranate fruit peel could be exploited as a potential source of natural antimicrobial and antioxidant agents as well as tyrosinase inhibitors.

Analysis of Phenolic Composition of Noble Muscadine (Vitis rotundifolia) by HPLC‐MS and the Relationship to Its Antioxidant Capacity

Phenolic compounds and anthocyanins in muscadines have attracted much attention due to their diverse biological activities. With bioassays of antioxidant activities in terms of total phenolic content (TPC), total anthocyanin content (TAC), total procyanidin content (TPA), oxygen radical absorbance capacity (ORAC), and ferric reducing antioxidant power (FRAP) of different parts of the Noble muscadine, the butanol (BuOH) extract of the muscadine skin showed the highest TPC (317.91 ± 1.83 mg GAE/100 g FW), which might be ascribed to its high TAC of 227.06 ± 1.29 mg/100 g fresh weight (FW). The ethyl acetate (EtOAc) extract of the muscadine seed contained the highest TPA (55.30 ± 0.63 mg CE/100 g FW). Correlation analyses demonstrated a significant linear relationship of TPC and TAC compared to their ORAC and FRAP values within the range of R(2) from 0.9283 to 0.9936, which suggested that phenolics and anthocyanins in the extracts contributed significantly to their antioxidant potential. Nineteen individual phenolics and 5 anthocyanins were identified by HPLC-MS, which indicated different chemical profiles of anthocyanins and other phenolics in the muscadine extracts. The paper has provided rich information of bioactive phytochemical profiles in different solvent extracts and their correlation with the antioxidant activity in the muscadine that is a very special regional fruit in U.S. Its high content of phenolic compounds demonstrates that muscadine could be beneficial to human health.

GC-MS Determination of Isoflavonoids in Seven Red Cuban Propolis Samples

In the present study, the phenolic composition analysis of seven red varieties of propolis, collected in different regions of Cuba, was evaluated by gas chromatography/mass spectrometry (GC-MS). Seventeen compounds were identified in all samples by the interpretation of their mass spectra. This appears to be the first report on the GC-MS analysis of isoflavonoids in the propolis. The results confirmed the presence of the main isoflavonoids isolated previously and suggested the general structure for the other five isoflavonoids. Vestitol, 7-O-methylvestitol, and medicarpin were present in high amounts in all propolis samples analyzed. This result indicates that propolis samples rich in isoflavonoids are not exclusively found in Pinar del Rio province and proves that GC-MS technique is a useful and alternative tool for the chemical analysis of tropical red propolis.