Effect of freezing and storage on the phenolics,ellagitannins, flavonoids,and antioxidant capacity of red raspberries

Scottish-grown red raspberries are a rich source of vitamin C and phenolics, most notably, the anthocyanins cyanidin-3-sophoroside, cyanidin-3-(2(G)-glucosylrutinoside), and cyanidin-3-glucoside, and two ellagitannins, sanguiin H-6 and lambertianin C, which are present together with trace levels of flavonols, ellagic acid, and hydroxycinnamates. The antioxidant capacity of the fresh fruit and the levels of vitamin C and phenolics were not affected by freezing. When fruit were stored at 4 degrees C for 3 days and then at 18 degrees C for 24 h, mimicking the route fresh fruit takes after harvest to the supermarket and onto the consumer's table, anthocyanin levels were unaffected while vitamin C levels declined and those of elligitannins increased, and overall, there was no effect on the antioxidant capacity of the fruit. It is concluded, therefore, that freshly picked, fresh commercial, and frozen raspberries all contain similar levels of phytochemicals and antioxidants per serving.     

Cranberries and cranberry products: powerful in vitro, ex vivo, and in vivo sources of antioxidants

Cranberry products and especially cranberry juice (CJ) have been consumed for health reasons primarily due to their effect on urinary tract infections. We investigated the quantity of both free and total (after hydrolysis) phenolic antioxidants in cranberry products using the Folin assay. The order of amount of total polyphenols in cranberry foods on a fresh weight basis was as follows: dried > frozen > sauce > jellied sauce. On a serving size basis for all cranberry products, the order was as follows: frozen > 100% juice > dried > 27% juice > sauce > jellied sauce. High fructose corn syrup (HFCS) is a major source of sugar consumption in the U.S. and contains both glucose and fructose, potential mediators of oxidative stress. We investigated the effect of the consumption of HFCS and ascorbate with CJ antioxidants or without CJ (control) given to 10 normal individuals after an overnight fast. Plasma antioxidant capacity, glucose, triglycerides, and ascorbate were measured 6 times over 7 h after the consumption of a single 240 mL serving of the two different beverages. The control HFCS caused a slight decrease in plasma antioxidant capacity at all time points and thus an oxidative stress in spite of the presence of ascorbate. CJ produced an increase in plasma antioxidant capacity that was significantly greater than control HFCS at all time points. Postprandial triglycerides, due to fructose in the beverages, were mainly responsible for the oxidative stress and were significantly correlated with the oxidative stress as measured by the antioxidant capacity. Cranberries are an excellent source of high quality antioxidants and should be examined in human supplementation studies.     

Reliability of analytical methods for determining anthocyanins in blood orange juices

Quantitative analysis of anthocyanins was performed on a series of blood orange juices according to various spectrophotometric and HPLC methods, and the causes for different concentration resulting from the application of such procedures were investigated. Spectrophotometric methods utilizing aqueous ethanol as a solvent provided an anthocyanin content higher than that determined by HPLC. Discrepancies were ascribed to the use of impure standards and/or unsuitable calibration lines. The most consistent results with the HPLC findings were obtained by a method utilizing water as a solvent and cyanidin-3-glucoside as a standard. Actual concentration of anthocyanins in blood orange juice was remarkably lower than that currently determined by procedures used in the juice producing factories.     

Fatty acid pattern, oxidation product development, and antioxidant loss in muscle tissue of rainbow trout and Dicentrarchus labrax during growth

The levels of hydrophilic, lipophilic, and enzymatic antioxidants, the oxidative damage to lipids and proteins, and the fatty acid patterns of triglyceride and phospholipid fractions were assayed in fresh muscle tissue of rainbow trouts (Oncorhynchus mykiss) and sea basses (Dicentrarchus labrax) during aging, to investigate the correlation between oxidative stress and aging processes in fish. The present studies suggests that lipid peroxidation and accumulation of oxidized proteins during in vivo aging are most likely to be linked with an age-dependent decline of lipophilic antioxidants (CoQH(2), CoQ, and vitamin E) and vitamin C contents in muscle tissue, whereas fish aging is not linked to a decline in antioxidant enzymes and reduced glutathione levels. Lipophilic antioxidant and vitamin C levels represent a reliable marker of oxidative stress during aging, and their determination might be useful for the assessment of fish age.     

超滤对血橙果汁中抗氧化成分及总抗氧化能力的影响

采用管式聚偏氟乙烯(PVDF)超滤膜，探讨了超滤对血橙果汁中抗氧化成分及总抗氧化能力的影响。结果表明，其对维生素C和花青素类成分的保存率约为85%左右，对几种酚酸和类黄酮组分（除槲皮素外）的保存率均在90%以上。同未杀菌的血橙原汁相比，巴氏杀菌汁的总抗氧化能力(TAA)损失率为23%，而超滤澄清汁仅为10%左右，主要与维生素C和花青素含量损失有关。     

Oxidation of skeletal muscle myofibrillar proteins in oil-in-water emulsions: interaction with lipids and effect of selected phenolic compounds

The effect of selected phenolic compounds, namely, gallic acid, cyanidin-3-glucoside, (+)-epicatechin, chlorogenic acid, genistein and rutin (50 and 200 microM), and alpha-tocopherol (50 microM) against the oxidation of oil-in-water emulsions (37 degrees C/10 days) containing 1% myofibrillar proteins (MPs), was investigated. Emulsions containing 1% bovine serum albumin (BSA) were also prepared for comparative purposes. Protein oxidation was assessed by measuring the loss of natural tryptophan fluorescence and the protein carbonyl gain by using fluorescence spectroscopy. Lipid oxidation was concurrently analyzed by measuring the increase of conjugated dienes (CDs) and hexanal. Proteins inhibited lipid oxidation in oil-in-water emulsions, and MPs showed a more intense antioxidant activity than BSA. MPs were also more resistant to oxidative deterioration than BSA. The different antioxidant capacity of MPs and BSA and their susceptibility to suffer oxidative reactions might be derived from their different amino acid composition and three-dimensional structures. The addition of the phenolic compounds resulted in a variety of effects, including both antioxidant and pro-oxidant effects. Gallic acid, cyanidin-3-glucoside, and genistein were the most efficient inhibitors of lipid and protein oxidation. The chemical structure of the phenolic compounds as well as the nature and conformation of the proteins were greatly influential on the overall effect against oxidative reactions.     

Ellagitannins,flavonoids, and other phenolics in red raspberries and their contribution to antioxidant capacity and vasorelaxation properties

Analysis of extracts of Glen Ample raspberries (Rubus idaeus L.) by gradient, reverse phase HPLC with diode array and tandem mass spectrometry identified eleven anthocyanins, including cyanidin-3-sophoroside, cyanidin-3-(2(G)-glucosylrutinoside), cyanidin-3-glucoside, cyanidin-3-rutinoside, pelargonidin-3-sophoroside, pelargonidin-3-(2(G)-glucosylrutinoside), and pelargonidin-3-glucoside. Significant quantities of an ellagitannin, sanguiin H-6, with an M(r) of 1870 were detected along with lower levels of a second ellagitannin, lambertianin C, which has an M(r) of 2804. Other phenolic compounds that were detected included trace levels of ellagic acid and its sugar conjugates along with one kaempferol- and four quercetin-based flavonol conjugates. Fractionation by preparative HPLC revealed that sanguiin H-6 was a major contributor to the antioxidant capacity of raspberries together with vitamin C and the anthocyanins. Vasodilation activity was restricted to fractions containing lambertianin C and sanguiin H-6.     

Antioxidant activity-guided fractionation of blue wheat (UC66049 Triticum aestivum L.)

Antioxidant activity-guided fractionation based on three in vitro antioxidant assays (Folin-Ciocalteu, TEAC, and leucomethylene blue assays) was used to identify major antioxidants in blue wheat (UC66049 Triticum aestivum L.). After consecutive extractions with solvents of various polarities and multiple chromatographic fractionations, several potent antioxidants were identified by NMR spectroscopy and mass spectrometry. Anthocyanins (delphinidin-3-glucoside, delphinidin-3-rutinoside, cyanidin-3-glucoside, and cyanidin-3-rutinoside), tryptophan, and a novel phenolic trisaccharide (β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl-(1→6)-(4-hydroxy-3-methoxyphenyl)-β-D-glucopyranoside) were the most active water-extractable constituents. However, anthocyanins were found to be major contributors to the overall blue wheat antioxidant activity only when the extraction steps were performed under acidic conditions. Alkylresorcinols were among the most active antioxidants extractable with 80% ethanol in the TEAC assay. However, this may be due to a color change instead of a bleaching of the ABTS radical. Ferulic acid was found to be the major antioxidant in alkaline cell-wall hydrolysates. The contents of the most active antioxidants were determined.     

Phenolic composition and antioxidant activities in flesh and achenes of strawberries (Fragaria ananassa)

High performance liquid chromatography coupled with diode array and coulometric array detectors were used to characterize and quantify phenolic compounds in achenes and flesh of ripe strawberries (cv Totem and Puget Reliance). Total phenolics and total monomeric anthocyanins were measured and antioxidant activities were evaluated by the FRAP and the ORAC assays. Strawberries contained 1% achenes on a fresh weight basis; however, they contributed to about 11% of total phenolics and 14% of antioxidant activities in strawberries. Ellagic acid, ellagic acid glycosides, and ellagitannins were the main contributors to the antioxidant activities of achenes. The major anthocyanin in flesh was pelargonidin-3-glucoside, whereas achenes consisted of nearly equal amounts of cyanidin-3-glucoside and pelargonidin-3-glucoside. Phenolic content and antioxidant activity of strawberry achenes were reduced by industrial processing. However, the levels were still high and strawberry waste byproduct could thus be a possible source of nutraceuticals or natural antioxidants.     

Influence of organic versus conventional agricultural practice on the antioxidant microconstituent content of tomatoes and derived purees; consequences on antioxidant plasma status in humans

The present study aims first to compare the antioxidant microconstituent contents between organically and conventionally grown tomatoes and, second, to evaluate whether the consumption of purees made of these tomatoes can differently affect the plasma levels of antioxidant microconstituents in humans. When results were expressed as fresh matter, organic tomatoes had higher vitamin C, carotenoids, and polyphenol contents (except for chlorogenic acid) than conventional tomatoes. When results were expressed as dry matter, no significant difference was found for lycopene and naringenin. In tomato purees, no difference in carotenoid content was found between the two modes of culture, whereas the concentrations of vitamin C and polyphenols remained higher in purees made out of organic tomatoes. For the nutritional intervention, no significant difference (after 3 weeks of consumption of 96 g/day of tomato puree) was found between the two purees with regard to their ability to affect the plasma levels of the two major antioxidants, vitamin C and lycopene.     

Procyanidins from Vitis vinifera seeds: in vivo effects on oxidative stress

The purpose of this study was to evaluate the effect of supplementation with procyanidins from Vitis vinifera on markers of oxidative stress. Ten healthy volunteers received a daily dose of 110 mg of procyanidins for 30 days. Fasting venous blood samples were taken before and at the end of the supplementation period and after 7 days of wash-out. The total antioxidant activity and the plasma concentrations of alpha-tocopherol were not modified. Conversely, the levels of alpha-tocopherol in red blood cell membranes increased significantly from 1.8 +/- 0.1 to 2.8 +/- 0.2 mg/g. Similarly, the lymphocyte oxidized DNA [8-oxo-7,8-dihydro-2'-deoxyguanosine/2'-deoxyguanosine ratio] was reduced from 7.23 +/- 2.47 to 2.34 +/- 0.51, and the red blood cell membrane fatty acid composition shifted to a higher level of polyunsaturated fatty acids. On the basis of these results, it may be suggested that dietary procyanidins exert their antioxidant protection in vivo by sparing liposoluble vitamin E and reducing DNA oxidative damage.     

Effect of processing techniques at industrial scale on orange juice antioxidant and beneficial health compounds

Phenolic compounds, vitamin C (L-ascorbic acid and L-dehydroascorbic acid), and antioxidant capacity were evaluated in orange juices manufactured by different techniques. Five processes at industrial scale (squeezing, mild pasteurization, standard pasteurization, concentration, and freezing) used in commercial orange juice manufacturing were studied. In addition, domestic squeezing (a hand processing technique) was compared with commercial squeezing (an industrial FMC single-strength extraction) to evaluate their influences on health components of orange juice. Whole orange juice was divided into soluble and cloud fractions after centrifugation. Total and individual phenolics were analyzed in both fractions by HPLC. Commercial squeezing extracted 22% more phenolics than hand squeezing. The freezing process caused a dramatic decrease in phenolics, whereas the concentration process caused a mild precipitation of these compounds to the juice cloud. In pulp, pasteurization led to degradation of several phenolic compounds, that is, caffeic acid derivatives, vicenin 2 (apigenin 6,8-di-C-glucoside), and narirutin (5,7,4'-trihydroxyflavanone-7-rutinoside) with losses of 34.5, 30.7, and 28%, respectively. Regarding vitamin C, orange juice produced by commercial squeezing contained 25% more of this compound than domestic squeezing. Mild and standard pasteurization slightly increased the total vitamin C content as the contribution from the orange solids parts, whereas concentration and freezing did not show significant changes. The content of L-ascorbic acid provided 77-96% of the total antioxidant capacity of orange juice. Mild pasteurization, standard pasteurization, concentration, and freezing did not affect the total antioxidant capacity of juice, but they did, however, in pulp, where it was reduced by 47%.     

Characterization of major anthocyanins and the color of red-fleshed Budd Blood orange (Citrus sinensis)

High-performance liquid chromatography (HPLC) with photodiode array detection was applied for the characterization of anthocyanins in red-fleshed Budd Blood (Citrus sinensis) orange. More than seven anthocyanin pigments were separated within 30 min by using a binary gradient (0.1% H(3)P0(4) in water and 0.1% H(3)PO(4) in acetonitrile) elution on a Prodigy ODS column. Separations by reversed-phase HPLC and semipreparative HPLC on a Prodigy 10-microm ODS Prep column, and acid and alkali hydrolyses were used for identification of anthocyanins. The primary anthocyanins in Budd Blood orange grown in Florida were cyanidin-3-(6"-malonylglucoside) (44.8%) followed by cyanidin-3-glucoside (33.6%). Two other minor pigments were also acylated with malonic acid. Malonated anthocyanins represented the major proportion (>51%) of anthocyanins in Budd Blood orange. Total anthocyanin contents and juice color parameters (CIE L,a,b) were compared with six other Florida-grown blood oranges.     

Juice and phenolic fractions of the berry Aristotelia chilensis inhibit LDL oxidation in vitro and protect human endothelial cells against oxidative stress

Oxidative modification of low-density lipoprotein (LDL) particles is a key event in the development of atherosclerosis. Oxidized LDL induces oxidative stress and modifies gene expression in endothelial cells. Berries constitute a rich dietary source of phenolic antioxidants. We found that the endemic Chilean berry Aristotelia chilensis (ach) has higher phenol content and scores better for total radical-trapping potential and total antioxidant reactivity in in vitro antioxidant capacity tests, when compared to different commercial berries. The juice of ach is also effective in inhibiting copper-induced LDL oxidation. In human endothelial cell cultures, the addition of ach juice significantly protects from hydrogen peroxide-induced intracellular oxidative stress and is dose-dependent. The aqueous, anthocyanin-rich fraction of ach juice accounts for most of ach's antioxidant properties. These results show that ach is a rich source of phenolics with high antioxidant capacity and suggest that it may have antiatherogenic properties.     

Effect of processing of black currant press-residue on polyphenol composition and cell proliferation

The press-residue of black currants provides a good source of phenolic antioxidants. The purpose of this study was to optimize the extraction of phenolic compounds from the press-residue by use of extraction conditions compatible with food use. The effects of temperature, extraction duration, and use of ultrasound-assisted extraction on the juice yield, total phenolics (TP), and anthocyanin content of aqueous extracts were studied. Within the variables and response factors tested, the optimal conditions were a 15 min extraction at 90 °C. No significant effect from ultrasound-assisted extraction was found. The composition of anthocyanins and polyphenols was highly dependent on the extraction temperature. The percentage contribution of delphinidin- and cyanidin-3-rutinoside to TP had a negative linear correlation with temperature, while delphinidin- and cyanidin-3-glucoside had a positive linear correlation with temperature, with a maximum amount obtained at 80 °C and 55 °C, respectively. Furthermore, extracts obtained at higher temperatures showed a stronger inhibition of proliferation of Caco-2, HT-29, and HCT 116 cells than extracts obtained at lower temperatures. This may be due to the decomposition of complex polyphenols at higher temperatures, making them more accessible to the cells.     

Phenolic composition and antioxidant properties of Polish blue-berried honeysuckle genotypes by HPLC-DAD-MS, HPLC postcolumn derivatization with ABTS or FC, and TLC with DPPH visualization

In this study, different Polish cultivars of blue-berried honeysuckles (Lonicera caerulea L.), wild and bog bilberry, were analyzed for bioactive compounds. The chemical properties verified included composition of anthocyanins and other polyphenols, antioxidant activity, and profiles of antioxidants by HPLC postcolumn derivatization or TLC. The antioxidant activities of different blue-berried honeysuckle cultivars were similar to that of wild-growing bilberries (ranging from 170 to 417 μmol TE/g dm in ABTS and from 93 to 166 μmol TE/g dm in DPPH and Folin-Ciocalteu tests). The major anthocyanin in the blue-berried honeysuckle was cyanidin-3-glucoside, which constituted 84-92% of the total anthocyanins. The TLC and HPLC postcolumn antioxidant profiles indicated that anthocyanins are the major antioxidants in all berries studied. Wild berries and the cultivars of the blue-berried honeysuckles are also a similar source of such minerals as K, Mg, and Ca.     

Phenolic antioxidants and antiatherogenic effects of Marula (Sclerocarrya birrea Subsp. caffra) fruit juice in healthy humans

Antioxidant activity and composition of Israeli-grown marula ( Sclerocarrya birrea subsp. caffra) fruit juice and health-promoting aspects of juice consumption on serum lipids and lipoproteins pattern in healthy volunteers were studied. Marula juice was found to contain high vitamin C and potassium levels and low sugar concentration (267 mg dL (-1), 328 mg dL (-1), and 7.3 g dL (-1), respectively). The juice contains a significant level of phenolics (56 mg of pyrogallol equiv dL (-1)) and was found to be a potent antioxidant (382 mg of vitamin C equiv dL (-1)). The antioxidant activity was resistant to pasteurization regimens and long-term freezing and slowly decreased during refrigeration, losing up to 14% of its capacity after 4 weeks. Three-week administration of the juice as a food supplement to healthy subjects significantly reduced their serum total cholesterol (by 8%), LDL-cholesterol concentration (by 17%), and triglyceride level (by 7%), increased their serum HDL-cholesterol level (by 10%), and attenuated serum oxidative stress. Upon a 4 week "washout" period, most of these parameters returned toward baseline values. Separation of the juice soluble phenolics by HPLC produced potent antioxidant fractions, tentatively containing hydrolyzable tannins, catechins, and hydroxycinnamic acid derivatives, which could be responsible for the observed protection against atherosclerosis risk factors following marula fruit juice consumption.     

Isolation and identification of strawberry phenolics with antioxidant and human cancer cell antiproliferative properties

Studies suggest that consumption of berry fruits, including strawberries ( Fragaria x ananassa Duch.), may have beneficial effects against oxidative stress mediated diseases such as cancer. Berries contain multiple phenolic compounds, which are thought to contribute to their biological properties. Comprehensive profiling of phenolics from strawberries was previously reported using high-performance liquid chromatography with mass spectrometry (HPLC-MS) detection. The current study reports the isolation and structural characterization of 10 phenolic compounds from strawberry extracts using a combination of Amberlite XAD16-resin and C18 columns, HPLC-UV, and nuclear magnetic resonance (NMR) spectroscopy methods. The phenolics were cyanidin-3-glucoside ( 1), pelargonidin (2), pelargonidin-3-glucoside (3), pelargonidin-3-rutinoside (4), kaempferol (5), quercetin (6), kaempferol-3-(6'-coumaroyl)glucoside) (7), 3,4,5-trihydroxyphenyl-acrylic acid (8), glucose ester of ( E)- p-coumaric acid (9), and ellagic acid . Strawberry crude extracts and purified compounds 1- 10 were evaluated for antioxidant and human cancer cell antiproliferative activities by the Trolox equivalent antioxidant capacity (TEAC) and luminescent ATP cell viability assays, respectively. Among the pure compounds, the anthocyanins 1 (7156 microM Trolox/mg), 2 (4922 microM Trolox/mg), and 4 (5514 microM Trolox/mg) were the most potent antioxidants. Crude extracts (250 microg/mL) and pure compounds (100 microg/mL) inhibited the growth of human oral (CAL-27, KB), colon (HT29, HCT-116), and prostate (LNCaP, DU145) cancer cells with different sensitivities observed between cell lines. This study adds to the growing body of data supporting the bioactivities of berry fruit phenolics and their potential impact on human health.     

Honey with high levels of antioxidants can provide protection to healthy human subjects

Free radicals and reactive oxygen species (ROS) have been implicated in contributing to the processes of aging and disease. Humans protect themselves from these damaging compounds, in part, by absorbing antioxidants from high-antioxidant foods. This report describes the effects of consuming 1.5 g/kg body weight of corn syrup or buckwheat honey on the antioxidant and reducing capacities of plasma in healthy human adults. The corn syrup treatment contained 0.21 +/- 0.06 mg of phenolic antioxidants per gram, and the two buckwheat honey treatments contained 0.79 +/- 0.02 and 1.71 +/- 0.21 mg of phenolic antioxidants per gram. Following consumption of the two honey treatments, plasma total-phenolic content increased (P < 0.05) as did plasma antioxidant and reducing capacities (P < 0.05). These data support the concept that phenolic antioxidants from processed honey are bioavailable, and that they increase antioxidant activity of plasma. It can be speculated that these compounds may augment defenses against oxidative stress and that they might be able to protect humans from oxidative stress. Given that the average sweetener intake by humans is estimated to be in excess of 70 kg per year, the substitution of honey in some foods for traditional sweeteners could result in an enhanced antioxidant defense system in healthy adults.     

In vitro and in vivo antioxidant and anti-inflammatory capacities of an antioxidant-rich fruit and berry juice blend. Results of a pilot and randomized, double-blinded, placebo-controlled, crossover study

This study investigated the in vitro and in vivo antioxidant and anti-inflammatory properties of a juice blend (JB), MonaVie Active, containing a mixture of fruits and berries with known antioxidant activity, including acai, a palm fruit, as the predominant ingredient. The phytochemical antioxidants in the JB are primarily in the form of anthocyanins, predominantly cyanidin 3-rutoside, cyanidin 3-diglycoside, and cyanidin 3-glucoside. The cell-based antioxidant protection of erythrocytes (CAP-e) assay demonstrated that antioxidants in the JB penetrated and protected cells from oxidative damage ( p < 0.001), whereas polymorphonuclear cells showed reduced formation of reactive oxygen species ( p < 0.003) and reduced migration toward three different pro-inflammatory chemoattractants: fmlp ( p < 0.001), leukotriene B4 ( p < 0.05), and IL-8 ( p < 0.03). A randomized, double-blinded, placebo-controlled, crossover trial with 12 healthy subjects examined the JB's antioxidant activity in vivo. Blood samples at baseline, 1 h, and 2 h following consumption of the JB or placebo were tested for antioxidant capacity using several antioxidant assays and the TBARS assay, a measure of lipid peroxidation. A within subject comparison showed an increase in serum antioxidants at 1 h ( p < 0.03) and 2 h ( p < 0.015), as well as inhibition of lipid peroxidation at 2 h ( p < 0.01) postconsumption.