Saskatoon and wild blueberries have higher anthocyanin contents than other Manitoba berries

Studies have shown that anthocyanins present in berry fruits have some beneficial health effects such as reducing age-associated oxidative stress and possessing anti-inflammatory properties. Therefore, six Manitoba berries (wild blueberry, Saskatoon berry, raspberry, chokecherry, strawberry, and seabuckthorn) were studied for their anthocyanin compositions (mg/100 g) on dry weight basis. Saskatoon berry and wild blueberry showed a high content of total anthocyanins (562.4 and 558.3 mg/100 g, respectively) that were not significantly (P>0.05) different from each other. The corresponding values for other berries: raspberry (365.2 mg/100 g), chokecherry (177.39 mg/100 g), and strawberry (97.5 mg/100 g) were significantly different from each other (P<0.05), and the total anthocyanin content of seabuckthorn was negligible (0.84 mg/100 g). Fifteen major anthocyanins were isolated from Manitoba berries. Saskatoon berry and wild blueberry contained higher amounts of delphinidin 3-glucoside (Dp-3-glc), malvidin 3-glucoside (Mv-3-glc), and malvidin 3-galactoside (Mv-3-gal). Dp-3-glc was 263.8 (mg/100 g) in Saskatoon berry and 84.4 (mg/100 g) in wild blueberry, whereas the corresponding values for Mv-3-glc in these berries were 47.4 and 139.6 (mg/100 g), respectively. Raspberry, strawberry, and chokecherry contained higher amounts of cyanidin 3-glucoside (Cy-3-glc), cyanidin 3-rutinoside (Cy-3-rut), and pelargonidin 3-glucoside (Pg-3-glc). The total anthocyanin content of Manitoba fruits followed the order: Saskatoon berry and blueberry (high anthocyanin berries), raspberry and chokecherry (medium anthocyanin berries), strawberry (low anthocyanin berries), and seabuckthorn (negligible anthocyanin berries). This study demonstrated that Saskatoon berries and wild blueberries have high potential value for fruit growers as well as the food and nutraceutical manufacturers because of their high anthocyanin contents.     

Distribution and contents of phenolic compounds in eighteen Scandinavian berry species

Berries contain a wide range of phenolic compounds in different conjugated forms, a fact that makes their simultaneous analysis a difficult task. In this work, soluble and insoluble phenolic compounds were identified and quantified in 18 species of berries by reversed phase high-performance liquid chromatography combined with diode array detection. The analytical results and literature data were used for the identification of the predominant conjugated hydroxycinnamic acids, flavonol glycosides, and anthocyanins in berries from six families, viz. Grossulariaceae, Ericaceae, Rosaceae, Empetraceae, Elaeagnaceae, and Caprifoliaceae. The study showed distinctive similarities among berry species of the same family in the distribution of conjugated forms of phenolic compounds but differences in chromatographic profiles of conjugates and compositions of aglycones especially in the case of anthocyanins. The chromatographic profiles of chokeberry and the related sweet rowanberry (Rosaceae) were exceptionally similar. These data are informative to studies on the authenticity of berry raw materials as well as to those on the evaluation of berries as sources of phenolic compounds.     

Effects of vine or bunch shading on the glycosylated flavor precursors in grapes of Vitis vinifera L. Cv. syrah

Effects of the modification of vine or bunch environment on glycoconjugates were studied in Syrah berries over two years. Vines were shaded from berry set to maturity, with black polyethylene nets of different mesh size to obtain 30 and 50% of the direct sunlight. Bunches were naturally shaded by the leaves or artificially with 90% shade bags. Sun-exposed berries were chosen as control berries. A quantitative decrease in levels of glycoconjugates was observed in shaded bunches, particularly for phenolic and C(13)-norisoprenoidic glycosides. In the same way, vine shading caused a decrease in the contents of glycosides of terpenols, phenols, and C(13)-norisoprenoids in berries, but the grape environment (microclimate) affected the berry composition more than the vine environment. A cluster thinning experiment confirmed the independence of grapes with regard to the plant for the biosynthesis of the C(13)-norisoprenoid glycosides.     

Berry phenolics and their antioxidant activity

Phenolic profiles of a total of 26 berry samples, together with 2 apple samples, were analyzed without hydrolysis of glycosides with HPLC. The phenolic contents among different berry genera varied considerably. Anthocyanins were the main phenolic constituents in bilberry, bog-whortleberry, and cranberry, but in cowberries, belonging also to the family Ericaceae genus Vaccinium, flavanols and procyanidins predominated. In the family Rosaceae genus Rubus (cloudberry and red raspberry), the main phenolics found were ellagitannins, and in genus Fragaria (strawberry), ellagitannins were the second largest group after anthocyanins. However, phenolic acids were dominant in rowanberries (genus Sorbus) and anthocyanins in chokeberry (genus Aronia). In the family Grossulariaceae genus Ribes (currants and gooseberry), anthocyanins predominated, as well as in crowberries (family Empetraceae genus Empetrum). In apples, hydroxycinnamic acids were the main phenolic subgroup. Extraction methods for berries and apples were studied to produce phenolic extracts with high antioxidant activity. Evaluation of antioxidant activity was performed by autoxidazing methyl linoleate (40 degrees C, in the dark). The extraction method affected remarkably both the phenolic composition and the antioxidant activity, but with statistical analysis the observed activity could not be well explained with the contents of individual phenolic subgroups.     

Characterization of flavonols in cranberry (Vaccinium macrocarpon) powder

Flavonoids were extracted from cranberry powder with acetone and ethyl acetate and subsequently fractionated with Sephadex LH-20 column chromatography. The fraction eluted with a 60% methanol solution was composed primarily of phenolic constituents with maximum absorbance at 340 nm. A high-performance liquid chromatography procedure was developed, which resolved 22 distinct peaks with UV/vis and mass spectra corresponding to flavonol glycoside conjugates. Six new constituents not previously reported in cranberry or in cranberry products were determined through NMR spectroscopy to be myricetin-3-beta-xylopyranoside, quercetin-3-beta-glucoside, quercetin-3-alpha-arabinopyranoside, 3'-methoxyquercetin-3-alpha-xylopyranoside, quercetin-3-O-(6' '-p-coumaroyl)-beta-galactoside, and quercetin-3-O-(6' '-benzoyl)-beta-galactoside. Quercetin-3-O-(6' '-p-coumaroyl)-beta-galactoside and quercetin-3-O-(6' '-benzoyl)-beta-galactoside represent a new class of cranberry flavonol compounds with three conjugated components consisting of a flavonol, sugar, and carboxylic acid (benzoic or hydroxycinnamic acids). This is also the first report identifying quercetin-3-arabinoside in both furanose and pyranose forms in cranberry. Elucidation of specific flavonol glycosides in cranberry is significant since the specificity of the sugar moiety may play a role in the bioavailability of the flavonol glycosides in vivo.     

Phenolic acids in berries, fruits, and beverages

The contents of soluble and total phenolic acids were analyzed in samples of 29 berries and berry products, 24 fruits and fruit peels, and 12 beverages. Variation of phenolic acids in berries was also studied. Soluble phenolic acids were extracted with methanolic acetic acid, and a tentative quantification was performed by high-performance liquid chromatography (HPLC). The total phenolic acid content was determined by HPLC after alkaline and acid hydrolyses. The content of total phenolic acids as aglycones in the above samples varied from 0 (pear cider) to 103 mg/100 g fresh weight (rowanberry). Besides rowanberry, the best phenolic acid sources among berries were chokeberry (96 mg/100 g), blueberry (85 mg/100 g), sweet rowanberry (75 mg/100 g), and saskatoon berry (59 mg/100 g). Among fruits, the highest contents (28 mg/100 g) were determined in dark plum, cherry, and one apple variety (Valkea Kuulas). Coffee (97 mg/100 g) as well as green and black teas (30-36 mg/100 g) were the best sources among beverages. Caffeic acid dominated in all of these samples except in tea brews. Variation in the phenolic acid contents of the berries was either small or moderate.     

Influence of growing season on phenolic compounds and antioxidant properties of grape berries from vines grown in subtropical climate

The influence of growing season (winter vs summer) on the synthesis and accumulation of phenolic compounds and antioxidant properties was studied in five grape cultivars for three consecutive years. Four phenolic compound parameters (total phenols, flavonoids, flavan-3-ols, and anthocyanins) and three antioxidant property parameters [2,2-diphenyl-1-picrylhydrazyl radical scavenging, 2,2-azinobis(3-ethylbenzothiazolinesulfonic acid) radical scavenging, and ferric reducing antioxidant power] were investigated. Results showed that both phenolic compounds and antioxidant properties in the seed and skin of winter berries were significantly (p < 0.05) higher than those of summer berries for all of the cultivars investigated. The anthocyanin profiles of berry skins appeared to be extremely consistent in different years for the same crop, whereas they varied greatly between the two crops within the same year (winter vs summer). Winter berries contained richer glucosides of delphinidin, cyanidin, peonidin, and malvidin than summer berries. These seasonal variations of phenolic compounds and antioxidant properties on grape berries were largely contributed by climatic factors such as temperature, solar radiation, rainfall, and hydrothermic coefficient between different growing seasons.     

Polyphenol screening of pomace from red and white grape varieties (Vitis vinifera L.) by HPLC-DAD-MS/MS

Phenolic compounds of 14 pomace samples originating from red and white winemaking were characterized by HPLC-MS. Up to 13 anthocyanins, 11 hydroxybenzoic and hydroxycinnamic acids, and 13 catechins and flavonols as well as 2 stilbenes were identified and quantified in the skins and seeds by HPLC-DAD. Large variabilities comprising all individual phenolic compounds were observed, depending on cultivar and vintage. Grape skins proved to be rich sources of anthocyanins, hydroxycinnamic acids, flavanols, and flavonol glycosides, whereas flavanols were mainly present in the seeds. However, besides the lack of anthocyanins in white grape pomace, no principal differences between red and white grape varieties were observed. This is the first study presenting comprehensive data on the contents of individual phenolic compounds comprising all polyphenolic subclasses of grapes including a comparison of several red and white pomaces from nine cultivars. The results obtained in the present study confirm that both skins and seeds of most grape cultivars constitute a promising source of polyphenolics.     

Profiling of hydroxycinnamoyl tartrates and acylated anthocyanins in the skin of 34 Vitis vinifera genotypes

The diversity of berry skin flavonoids in grape genotypes has been previously widely investigated with regard to major compounds (nonacylated anthocyanins and flavonols), but much less with regard to acylated anthocyanins and hydroxycinnamoyl tartrates (HCTs). In this study, the composition of the phenolic fraction of the berry skin (free and acylated anthocyanins, flavonols, and HCTs) was assessed on 34 grapevine genotypes grown in a collection vineyard in northwestern Italy. The phenolic fraction was profiled on berries collected in the same vineyard, at the same ripening level across two successive vintages. The anthocyanin, HCT, and flavonol profiles were specific of each genotype, and the first two were relatively little affected by the vintage. A wide diversity in the polyphenolic fraction was shown among cultivars. Besides expected discriminatory effects of free anthocyanins and flavonol profiles, principal component analyses allowed a good discrimination of cultivars on the basis of coumaroylated anthocyanins and of the HCT profile. Anthocyanins were mostly acylated by aromatic acids, and acylation was independent from the anthocyanin substrate. HCTs were present mostly as coumaroyl and caffeoyl derivatives, and no correlation was observed between the same acylation patterns of tartrate and of anthocyanins. The results of this study are discussed in the light of new hypotheses on still unknown biosynthetic steps of phenolic substances and of the potential use of these substances in discrimination and identification of different grape cultivars in wines.     

Compositional differences of phenolic compounds between black currant (Ribes nigrum L.) cultivars and their response to latitude and weather conditions

Phenolic compounds in black currants of three Finnish cultivars and their response to growth latitude and weather conditions were analyzed over a six-year period. 'Melalahti' had lower contents of total phenolic compounds (31.4% and 29.2% lower than 'Mortti' and 'Ola', respectively), total anthocyanins (32.6% and 30.5%), and total hydroxycinnamic acid derivatives (23.1% and 23.8%) (p < 0.05) and was less affected by growth latitude and weather conditions than 'Mortti' and 'Ola'. However, all the cultivars grown at higher latitude (66°34' N) had lower contents of total flavonols, total anthocyanins, and total phenolic compounds than those grown at lower latitude (60°23' N) (p < 0.05). The content of total hydroxycinnamic acid conjugates did not vary in 'Melalahti' (p > 0.05) but increased as the latitude increased in 'Mortti' and 'Ola' (p < 0.05). Temperature and radiation were the major weather variables influencing the composition of phenolic compounds. Delphinidin-3-O-glucoside, delphinidin-3-O-rutinoside, and myricetin-3-O-glucoside content showed positive correlations with temperature and radiation in all three cultivars. The study gives important guidelines for the selection of raw materials and growth sites as well as for the berry cultivation for commercial exploitation of black currant berries.     

Preparative separation of polyphenols from tea by high-speed countercurrent chromatography

High-speed countercurrent chromatography (HSCCC) was applied to the separation of polyphenols from tea leaves (Camellia sinensis L.). The capability of HSCCC to isolate pure tea polyphenols from complex mixtures on a preparative scale was demonstrated for catechins, flavonol glycosides, proanthocyanidins, and strictinin from green and black tea. The purity and identity of isolated compounds was confirmed by (1)H NMR and HPLC-ESI-MS/MS. Gram quantities of polyphenols from tea can be isolated with the procedure described.     

Phenolic constituents of shea (Vitellaria paradoxa) kernels

Analysis of the phenolic constituents of shea (Vitellaria paradoxa) kernels by LC-MS revealed eight catechin compounds-gallic acid, catechin, epicatechin, epicatechin gallate, gallocatechin, epigallocatechin, gallocatechin gallate, and epigallocatechin gallate-as well as quercetin and trans-cinnamic acid. The mean kernel content of the eight catechin compounds was 4000 ppm (0.4% of kernel dry weight), with a 2100-9500 ppm range. Comparison of the profiles of the six major catechins from 40 Vitellaria provenances from 10 African countries showed that the relative proportions of these compounds varied from region to region. Gallic acid was the major phenolic compound, comprising an average of 27% of the measured total phenols and exceeding 70% in some populations. Colorimetric analysis (101 samples) of total polyphenols extracted from shea butter into hexane gave an average of 97 ppm, with the values for different provenances varying between 62 and 135 ppm of total polyphenols.     

Microclimate influence on mineral and metabolic profiles of grape berries

The grape berry microclimate is known to influence berry quality. The effects of the light exposure of grape berry clusters on the composition of berry tissues were studied on the "Merlot" variety grown in a vineyard in Bordeaux, France. The light exposure of the fruiting zone was modified using different intensities of leaf removal, cluster position relative to azimuth, and berry position in the cluster. Light exposures were identified and classified by in situ measurements of berry temperatures. Berries were sampled at maturity (>19 Brix) for determination of skin and/or pulp chemical and metabolic profiles based on (1) chemical and physicochemical measurement of minerals (N, P, K, Ca, Mg), (2) untargeted 1H NMR metabolic fingerprints, and HPLC targeted analyses of (3) amino acids and (4) phenolics. Each profile defined by partial least-square discriminant analysis allowed us to discriminate berries from different light exposure. Discriminant compounds between shaded and light-exposed berries were quercetin-3-glucoside, kaempferol-3-glucoside, myricetin-3-glucoside, and isorhamnetin-3-glucoside for the phenolics, histidine, valine, GABA, alanine, and arginine for the amino acids, and malate for the organic acids. Capacities of the different profiling techniques to discriminate berries were compared. Although the proportion of explained variance from the 1H NMR fingerprint was lower compared to that of chemical measurements, NMR spectroscopy allowed us to identify lit and shaded berries. Light exposure of berries increased the skin and pulp flavonols, histidine and valine contents, and reduced the organic acids, GABA, and alanine contents. All the targeted and nontargeted analytical data sets used made it possible to discriminate sun-exposed and shaded berries. The skin phenolics pattern was the most discriminating and allowed us to sort sun from shade berries. These metabolite classes can be used to qualify berries collected in an undetermined environment. The physiological significance of light and temperature effects on berry composition is discussed.     

Characterization of anthocyanins and proanthocyanidins in some cultivars of Ribes, Aronia, and Sambucus and their antioxidant capacity

Anthocyanins and proanthocyanidins were characterized by HPLC-ESI-MS/MS coupled with a diode array and/or fluorescent detector in seven cultivars of Ribes nigrum (black currant) and Ribes rubrum (red currant, Red Lake), six cultivars of Ribes grossularia (gooseberries), Aronia melanocarpa(chokeberry), and Sambucus nigra (elderberry). Thirty-one different anthocyanins were detected in these berries, but not every anthocyanin was observed in each berry. A number of minor anthocyanins were identified from these berries for the first time. The concentrations of individual anthocyanins in all of the berries were quantified using relevant anthocyanidin 3-glucoside standards. Among the berries studied in this paper and in berries in general, chokeberry has the highest total anthocyanin concentrations [1480 mg/100 g of fresh weight (FW)], whereas the lowest total anthocyanin concentration in the berries studied was found in the gooseberry cv. Careless, which contained only 0.07 mg/100 g of FW. Two cultivars of gooseberries (Marigold and Leveller) did not contain any anthocyanins. Total proanthocyanidin concentrations in the berries studied ranged from 23 to 664 mg/100 g of FW in elderberry and chokeberry, respectively. Procyanidin or prodelphinidin polymers were the predominant components (>65% w/w) in most of the berries. The lipophilic and hydrophilic antioxidant capacities were measured by the oxygen radical absorbance capacity (ORAC(FL)) procedure. The total antioxidant capacity varied from 21 micromol of TE/g of FW in Careless gooseberry to 161 micromol of TE/g of FW in chokeberry. Total phenolics in the berries in general paralleled hydrophilic antioxidant capacity.     

Phenolic profile of quince fruit (Cydonia oblonga Miller) (pulp and peel)

Qualitative and quantitative analyses of phenolic compounds were carried out on quince fruit samples from seven different geographical origins in Portugal. For each origin, both pulp and peel were analyzed by reversed-phase HPLC-DAD and HPLC-DAD/MS.The results revealed differences between the phenolic profiles of pulps and peels in all studied cases. The pulps contained mainly caffeoylquinic acids (3-, 4-, and 5-O-caffeoylquinic acids and 3,5-dicaffeoylquinic acid) and one quercetin glycoside, rutin (in low amount). The peels presented the same caffeoylquinic acids and several flavonol glycosides: quercetin 3-galactoside, kaempferol 3-glucoside, kaempferol 3-rutinoside, and several unidentified compounds (probably kaempferol glycoside and quercetin and kaempferol glycosides acylated with p-coumaric acid). The highest content of phenolics was found in peels.     

Composition of phenolic compounds in a Portuguese pear (Pyrus communis L. var. S. Bartolomeu) and changes after sun-drying

The composition of phenolic compounds of a Portuguese pear cultivar (Pyrus communis L. var. S. Bartolomeu) was determined by HPLC after thioacidolysis. The average concentration of phenolic compounds in pear harvested at commercial maturity stage was 3.7 g per kg of fresh pulp. Procyanidins were the predominant phenolics (96%), with a mean degree of polymerization (mDP) of 13-44; hydroxycinnamic acids (2%), arbutin (0.8%), and catechins (0.7%) were also present. The most abundant monomer in the procyanidin structures was (-)-epicatechin (99%), which was found as extension and terminal units; (+)-catechin (1%) was found only as a terminal unit. Sun-drying of these pears caused a decrease of 64% (on a dry pulp basis) in the total amount of native phenolic compounds. Hydroxycinnamic acids and procyanidins showed the largest decrease; the B2 procyanidin was not found at all in the sun-dried pear. Less affected were arbutin and catechins. In the sun-dried pear, the procyanidins with high mDP became unextractable in the solvents used.     

Improved HPLC determination of phenolic compounds in cv. golden delicious apples using a monolithic column

A rapid HPLC-DAD determination of phenols in apple using an RP monolithic column is reported. Because of the hydrodynamic advantages offered by this kind of column and the use of acidified acetonitrile as eluent, assays of apple extracts can be performed in <21 min. Assays of pulp and peel extracts were carried out without the need for time-consuming sample pretreatment except filtration. Several flavanols, hydroxycinnamic acids, dihydrochalcones, and six quercetin glycosides were identified and quantified. A seventh quercetin derivative, two chalcone-related compounds, and three hydroxycinnamic derivatives were also found. Peels proved to be richer in phenols than pulps, the former being composed mainly of (-)-epicatechin, procyanidin B2, chlorogenic acid, phloridzin, hyperin, and avicularin. In pulps, where the chlorogenic acid was the principal phenolic compound, quercetin glycosides were found in very low amounts.     

Content and profile of flavanoid and phenolic acid compounds in conjunction with the antioxidant capacity for a variety of northwest Vaccinium berries

This investigation evaluated the content and profile of flavanoid and phenolic acid compounds present in nine Vaccinium species that included domestic blueberry cultivars and sample collections from undomesticated colonies. The study was focused in two areas of inquiry. The first involved extracting and analyzing the berries for total phenolics (TPH), total anthocyanins (ACY), and the antioxidant capacity. Vaccinium species differ in their polyphenolic content, and these high TPH and ACY levels are correlated to their antioxidant capacity. Second, berry extracts were analyzed by high-performance liquid chromatography equipped with photodiode array and mass spectrometric detectors to determine the content and profile of selected bioactive compounds. The flavanoid analytes of interest included the anthocyanidins, flavan-3-ols, and flavonol aglycons, as well as specific phenolic acid components. This semicomprehensive analysis begins to characterize the phytochemical profiles and illustrates the differences in the content of polyphenolic compounds present within these Vaccinium species.     

UHPLC-PDA-ESI/HRMS/MS(n) analysis of anthocyanins, flavonol glycosides, and hydroxycinnamic acid derivatives in red mustard greens (Brassica juncea Coss variety)

An UHPLC-PDA-ESI/HRMS/MS(n) profiling method was used for a comprehensive study of the phenolic components of red mustard greens ( Brassica juncea Coss variety) and identified 67 anthocyanins, 102 flavonol glycosides, and 40 hydroxycinnamic acid derivatives. The glycosylation patterns of the flavonoids were assigned on the basis of direct comparison of the parent flavonoid glycosides with reference compounds. The putative identifications were obtained from tandem mass data analysis and confirmed by the retention time, elution order, and UV-vis and high-resolution mass spectra. Further identifications were made by comparing the UHPLC-PDA-ESI/HRMS/MS(n) data with those of reference compounds in the polyphenol database and in the literature. Twenty-seven acylated cyanidin 3-sophoroside-5-diglucosides, 24 acylated cyanidin 3-sophoroside-5-glucosides, 3 acylated cyanidin triglucoside-5-glucosides, 37 flavonol glycosides, and 10 hydroxycinnamic acid derivatives were detected for the first time in brassica vegetables. At least 50 of them are reported for the first time in any plant materials.     

HPLC analysis of flavonoids and secoiridoids in leaves of Ligustrum vulgare L. (Oleaceae)

Identification and quantification of flavonol glycosides and secoiridoids was carried out on leaves of Ligustrum vulgare L. (Oleaceae) by means of HPLC-DAD and HPLC-MS analysis. In addition to previously reported secoiridoids (oleuropein, ligustaloside A, ligustaloside B, and ligstroside) four kaempferol glycosides (kaempferol 3-O-glucoside 7-O-rhamnoside, kaempferol 3, 7-O-dirhamnoside, kaempferol 3-O-rhamnoside, and kaempferol 3-O-glucoside) and two quercetin glycosides (quercetin 3-O-glucoside 7-O-rhamnoside and quercetin 3,7-O-dirhamnoside) were present in leaves of L. vulgare L. Although secoiridoids accounted for nearly the 76% of the total leaf polyphenols content (with ligustaloside A as the main component), kaempferol glycosides were also accumulated in the leaves of L. vulgare L. to a relatively high extent (23%). Contribution of quercetin derivatives was minor under our experimental conditions. Our findings suggest that flavonol glycosides may have a central role in both the ecology and the biology of L. vulgare L.