Antioxidant activity of minimally processed red chicory (Cichorium intybus L.) evaluated in xanthine oxidase-, myeloperoxidase-, and diaphorase-catalyzed reactions

Minimally processed red chicory products (Cichorium intybus L. var. silvestre) were studied for their polyphenol content and antioxidant activity evaluated by using the synthetic 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl radical and three model reactions catalyzed by relevant enzymatic sources of reactive oxygen species, namely, xanthine oxidase, myeloperoxidase, and diaphorase. Products were analyzed at the time of production and after storage at 4 degrees C within either a gas permeable film or a gas barrier film. The antioxidant activity and contents of hydroxycinnamic acids and flavonoids decreased by less than 20% during storage of the minimally processed red chicory products. Total phenolics were significantly correlated with the antioxidant activity evaluated with both the synthetic radical and the enzyme-catalyzed reactions. On a molar basis, red chicory phenolics were as efficient as the reference compound Trolox in scavenging the synthetic radical. However, red chicory phenolics had a much higher inhibitory activity than Trolox in the model enzymatic systems.     

Antiradical activity of water soluble components in common diet vegetables

The antiradical activity of water-soluble components contained in mushrooms (Psalliota campestris), onions (Allium cepa), white cabbage (Brassica oleracea var. alba), and yellow bell peppers (Capsicum annuum) against hydroxyl radicals was tested in a chemical and biological system. The vegetable juices were obtained by centrifugation of a vegetable homogenate processed at 2 degrees C or heated at 102 degrees C. The chemical system consisted of a buffered reaction mixture composed of Fe(III)-EDTA, 2-deoxy-D-ribose, ascorbic acid, and H(2)O(2) generating the hydroxyl radical. The antiradical activity was expressed as an inhibition of deoxyribose degradation. The biological system consisted of IMR32 neuroblastoma cells exposed to H(2)O(2) in the presence or absence of the vegetable juices. Cells were pretreated for either 24 h or 1 h with the vegetable juices, and reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was used as a cell viability assay. All vegetable juices inhibited the degradation of deoxyribose and increased the viability of H(2)O(2) treated cells. Raw mushroom juice proved to be the most active in both cases. Boiling significantly affected the activity of mushroom juice, but did not change significantly the effect on onions and yellow bell peppers, and partially increased the activity of white cabbage juice. Mushroom antiradical activity was also confirmed by a cytofluorimetric analysis.     

Isolation of an in vitro and ex vivo antiradical melanoidin from roasted barley

The antiradical properties of water-soluble components of both natural and roasted barley were determined in vitro, by means of DPPH* assay and the linoleic acid-beta-carotene system, and ex vivo, in rat liver hepatocyte microsomes against lipid peroxidation induced by CCl4. The results show the occurrence in natural barley of weak antioxidant components. These are able to react against low reactive peroxyl radicals, but offer little protection against stable DPPH radicals deriving from peroxidation in microsomal lipids. Conversely, roasted barley yielded strong antioxidant components that are able to efficiently scavenge free radicals in any system used. The results show that the barley grain roasting process induces the formation of soluble Maillard reaction products with powerful antiradical activity. From roasted barley solution (barley coffee) was isolated a brown high molecular mass melanoidinic component, resistant to acidic hydrolysis, that is responsible for most of the barley coffee antioxidant activity in the biosystem.     

Polyphenol content and antioxidative activity in some species of freshly consumed salads

Ten genotypes belonging to Lactuca sativa, Cicorium intybus, Plantago coronopus, Eruca sativa, and Diplotaxis tenuifolia and used in fresh mixed salads were investigated for their polyphenol contents. Flavonoids and hydroxycinnamic acids were characterized by high-performance liquid chromatography (HPLC)/diode array detection/mass spectrometry. Quercetin, kaempferol, luteolin, apigenin, and crysoeriol derivatives were identified; hydroxycinnamic acids were all caffeoyl derivatives. The total polyphenol content was obtained through the Folin-Ciocalteu test and from the HPLC data. The amounts ranged between 0.9 and 4.7 mg/g fresh weight. The antiradical activity was determined by the reaction with the stable DPPH* radical. The Fe2+ chelating activity was determined with a spectrophotometric test. From the complex of data, a quite complete picture of the characteristics of the vegetables emerges. A cultivated C. intybus cultivar exhibited the highest polyphenol content, while a wild C. intybus genotype exhibited the highest antiradical activity. In every case, the characteristics of the different salads as functional foods have been pointed out.     

Purification and characterization of soluble Cichorium intybusVar. silvestre lipoxygenase

A water-soluble lipoxygenase enzyme (EC 1.13.11.12; LOX) occurring in the red cultivar produced in the geographical area of Chioggia (Italy) of Cichorium intybus var. silvestre was isolated and characterized. The molecular mass of the enzyme was estimated to be 74,000 Da by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration chromatography. The isoelectric point was pH 6.85. The optimum values of pH, ionic strength, and temperature, shown by isoresponse surface calculated by a randomized multilevel factorial design, were 7.58, 30 mM, and 38.5 degrees C, respectively. The enzyme showed high specificity toward linoleic acid, and the study of the variation of linoleic acid concentration between 30 and 300 microM, in the presence of Tween 20 at a concentration lower than the critical micelle concentration (0.01 v/v), resulted in a typical Michaelis-Mentem curve with KM and Vmax values of 1.49 x 10(-4) M and 2.049 microM min(-1) mg(-1), respectively. The biochemical properties, the kinetic parameters found, and the carotene-bleaching activity shown in aerobic conditions seem to indicate that the isolated enzyme is a lipoxygenase type III according to the indications given for soybean isoenzymes.     

Reduction kinetics of the antiradical probe 2,2-diphenyl-1-picrylhydrazyl in methanol and acetonitrile by the antiradical activity of protocatechuic acid and protocatechuic acid methyl ester

This work evaluates the reduction kinetics of the antiradical probe 2,2-diphenyl-1-picrylhydrazyl (DPPH (*)) in methanol and acetonitrile by the antiradical activity of protocatechuic acid (3,4-dihydroxybenzoic acid, 1) and protocatechuic acid methyl ester ( 2). The reduction kinetics of DPPH (*) in both solvents by the antiradical activity of the p-catechol group in 2 is regular, that is, coincide with the proposed standard kinetic model for the reduction kinetics of DPPH (*) by the antiradical activity of an isolated p-catechol group. Therefore, the antiradical activity of 2 experimentally exhibits two rate-two stoichiometric constants in acetonitrile and three rate--three stoichiometric constants in methanol. In contrast, the reduction kinetics of DPPH (*) in both solvents by the antiradical activity of the p-catechol group in 1 is perturbed, that is, deviate from the proposed standard kinetic model. The deviations arise from the presence of the reactive carboxylic acid function which, in methanol, induces an additional reversible side reaction and, in acetonitrile, turns an irreversible reaction reversible, thus modifying the otherwise regular reduction kinetics of DPPH (*) by the antiradical activity of the p-catechol group in 1. On the other hand, the approximated theoretical kinetic equation that applies for those p-catechol groups whose reduction kinetics is regular and that experimentally exhibit three rate--three stoichiometric constants has been derived and used for fitting.     

Alkylperoxyl radical-scavenging activity of various flavonoids and other phenolic compounds: implications for the anti-tumor-promoter effect of vegetables

We recently reported that alkylperoxyl radical (ROO(*)) enhanced carcinogenesis in rats treated with carcinogen (Sawa et al. Cancer Epidemiol. Biomarkers Prev. 1998, 7, 1007-1012), and the tumor promoting action of ROO(*) could be reduced by addition of hot-water extracts of vegetables (Maeda et al. Jpn. J. Cancer Res. 1992, 83, 923-928). Here we described the ROO(*)-scavenging activity of flavonoids and nonflavonoid phenolics and their role in anti-tumor-promoter effects. A model molecular species, ROO(*), was generated from tert-butyl hydroperoxide (t-BuOOH) and heme iron, and the scavenging of t-BuOO(*) was determined by (a) bioassay based on the bactericidal action of ROO(*), (b) luminol-enhanced chemiluminescence, and (c) electron spin resonance. Of 17 authentic plant phenolics tested, 9 compounds (including rutin, chlorogenic acid, vanillin, vanillic acid, neohesperidin, gallic acid, shikimic acid, rhamnetin, and kaempferol) showed remarkably high ROO(*)-scavenging activity. Some of them were detected and quantified in hot-water extracts of mung bean sprouts, used as the model vegetable, and their contents increased after germination, which paralleled very well to the ROO(*)-scavenging capacity of the vegetable extracts. Thus, a diet rich in these radical scavengers would reduce the cancer-promoting action of ROO(*). Consequently, the carcinogenic potentials of oxygen-related radicals may be suppressed.     

电阻抗分析在菊苣根冻害检测中的应用研究

以菊苣(CichoriumintybusLvarfoliosumcv.)根为试材,分析了低温下电阻抗和钾离子渗漏速率的变化及其与细胞膜透性变化的定量关系。结果表明:随着低温贮藏时间的延长和冻害的发展,菊苣根细胞膜透性增大,钾离子渗漏速率上升,组织的电阻抗值下降。3种温度下(0℃,-1℃,-3℃)贮藏的菊苣根其电阻抗值的变化均与钾离子渗漏速率呈显著的负相关关系。电阻抗对频率作图显示,在低频率范围(20～100Hz)可得到最大而且较稳定的电阻抗值。因此,电阻抗分析方法可以用来检测和评价植物的冻害     

Assessment of pro-oxidant activity of foods by kinetic analysis of crocin bleaching

The pro-oxidant activity of potent oxidants and foods was determined using the kinetic analysis of crocin bleaching. In its reduced form, crocin has an absorption band at 443 nm, which disappears upon oxidation by a generic radical species. Hydroxyl radicals generated by hydrogen peroxide, peroxyl radicals from ABAP, and the stable free radical DPPH(*) were allowed to react with crocin in an aqueous solution at 40 degrees C. Pro-oxidant activity was taken as the ratio between the decrease in crocin absorbance at 5 min and the relevant oxidant concentration. The test proposed was used to evaluate the pro-oxidant activity of widely consumed foods such as pasteurized skim milk and bread. They both exerted significant pro-oxidant activities, which were attributed to the early nonenzymatic browning products formed upon heat treatment.     

Antiradical properties of commercial cognacs assessed by the DPPH(.) test

Antiradical activities of some commercial cognacs were evaluated by the DPPH(*) test. Different mathematical models for the evaluation of the antiradical efficiency of the cognac samples were proposed and discussed. Nonflavonoid phenols were found to be the main substances responsible of the radical scavenging activity of cognacs. In particular the strongest correlations between antiradical activity measurements and cognac chemical characteristics was found for ellagitannins, high molecular weight polyphenols, which are extracted from the wood and solubilized in the spirit mainly during first year aging.     

Vitamin C equivalent antioxidant capacity (VCEAC) of phenolic phytochemicals

To express the antioxidant capacity of plant foods in a more familiar and easily understood manner (equivalent to vitamin C mg/100 g), two stable radical species, ABTS(*)(-) and DPPH(*), commonly used for antioxidant activity measurements, were employed independently to evaluate their efficacies using apple polyphenolic extracts and seven polyphenolic standards including synthetic Trolox. Their antioxidant activities were expressed as vitamin C equivalent antioxidant capacity (VCEAC) in mg/100 g apple or mg/100 mL of the reference chemical compounds in 10 and 30 min using the ABTS(*)(-) and DPPH(*) scavenging assays, respectively. The antioxidant capacity of Gala apples and seven phenolic standards, determined by both ABTS(*)(-) and DPPH(*) scavenging assays, showed a dose-response of the first-order. Fresh Gala apples had a VCEAC of 205.4 +/- 5.6 mg/100 g using the ABTS assay, and the relative VCEACs of phenolic standards were as follows: gallic acid > quercetin > epicatechin > catechin > vitamin C > rutin > chlorogenic acid > Trolox. With the DPPH radical assay, the VCEAC of fresh Gala apples was 136.0 +/- 6.6 mg/100 g, and the relative VCEACs of seven phenolic standards were, in decreasing order, as follows: gallic acid > quercetin > epicatechin > catechin > or = vitamin C > Trolox > rutin > chlorogenic acid. Because the ABTS assay can be used in both organic and aqueous solvent systems, employs a specific absorbance at a wavelength remote from the visible region, and requires a short reaction time, it is a more desirable method than the DPPH assay. Therefore, it is recommended that antioxidant capacity be expressed as vitamin C mg/100 g equivalent (VCEAC) using the ABTS assay.     

Effect of selenium foliar application on chicory (Cichorium intybus L.)

Leaves of young chicory (Cichorium intybus L.) plants were sprayed with selenate (1 mg SeVI/L) to establish the distribution of added selenium (Se) in the heads. Its concentration was analyzed in the outer, intermediate, and innermost leaves of chicory heads. The concentration of Se was about double (43-46 ng Se g-1 DM) that in the control (21-24 ng Se g-1 DM), indicating that the applied Se was transported from the sprayed leaves to the heads. In cv. Monivip, Se concentration was even throughout the head, but in cv. Anivip, the innermost leaves had a lower concentration of Se. No visual symptoms of Se toxicity appeared on the plants, and the quantum yield of photosystem II showed no indication that Se spraying could be harmful for energy conversion. Se increased the respiratory potential in young plants but not in plants at harvest time.     

Distribution of flavonoids and furocoumarins in juices from cultivars of Citrus bergamia Risso

HPLC separation of flavonoids and furocoumarins in the crude juices of three cultivars of Citrus bergamia Risso ("Castagnaro", "Fantastico", and "Femminello") was carried out on a C18 reversed phase column. The analysis was performed in a single run using a DAD detector coupled with an ESI-MS-MS source. Two furocoumarins (bergapten and bergamottin) were detected and quantified simultaneously with the sixteen flavonoid components previously found in industrial bergamot juice. Full characterization of the furocoumarins was performed by (1)H NMR analysis on samples separated by means of preparative HPLC. The free-radical scavenging ability of cultivar juices was assessed by using DPPH radical. The data presented show that the "Femminello" cultivar, even though it is the least common of the three, is by far the richest in health-promoting bioactive compounds (both flavonoids and furocoumarins). Given the range of applications of furocoumarins, the preparative separation described herein is proposed as a simple and rapid method to obtain this class of compounds in good yield from crude juice.     

Chemical characterization and biological effects of Sicilian Opuntia ficus indica (L.) mill. Fruit juice: antioxidant and antiulcerogenic activity

The juice of whole fruits of Sicilian cultivars of prickly pear (Opuntia ficus indica (L.) Mill.) was investigated, and the contents of ascorbic acid, total polyphenols, and flavonoids were determined. In the juice, ferulic acid was the chief derivative of hydroxycinnamic acid and the mean concentration of total phenolic compounds was 746 microg/mL. The flavonoid fraction, analyzed by high-performance liquid chromatography-diode array detection, consisted of rutin and isorhamnetin derivatives. The juice showed antioxidant activity in the DPPH(*) test, probably due to the phenolic compounds that are effective radical scavengers. The preventive administration of the juice inhibited the ulcerogenic activity of ethanol in rat. Light microscopy observations showed an increase in mucus production and the restoration of the normal mucosal architecture. The juice is nutritionally interesting, and its dietary intake could provide protection against oxidative damage.     

Urine flavonoids and plasma carotenoids in the validation of fruit, vegetable and tea intake during pregnancy in the Norwegian Mother and Child Cohort Study (MoBa)

OBJECTIVE: To validate a new food-frequency questionnaire (FFQ) for measuring the intake of fruit, vegetables and tea reported by women participating in the Norwegian Mother and Child Cohort Study (MoBa). DESIGN: Intake of fruits, vegetables and tea estimated by the FFQ was compared with urinary flavonoid excretion, plasma carotenoid concentration and intake measured by a 4-day weighed food diary (FD). The triangular method was applied to calculate FFQ validity coefficients using two independent biomarkers. SETTING AND SUBJECTS: One hundred and nineteen women participating in MoBa. RESULTS: The FFQ estimate of fruit intake was significantly correlated with urine phloretin (r = 0.33), citrus fruit/juice with urine hesperetin (r = 0.44), cooked vegetables with plasma alpha-carotene (r = 0.37), and tea with urine kaempferol (r = 0.41) (P < 0.01 for all). On average, 60% of the participants fell into the same or adjacent quintiles when classified by FFQ and biomarkers. Significant correlations between the FFQ and FD were found for fruit (r = 0.39), vegetables (r = 0.34), juices (r = 0.50) and tea (r = 0.53). The FFQ validity coefficient was 0.65 for citrus fruit/juice and 0.59 for cooked vegetables as calculated by the triangular method. CONCLUSIONS: The validation study shows that the MoBa FFQ can be used to estimate fruit, juice, vegetable and tea intake in pregnant Norwegian women, and to rank individuals within the distribution.     

Antioxidant characterization of some Sicilian edible wild greens

Epidemiological studies have demonstrated that many antioxidants and the total antioxidant capacity (TAC) of the diet may protect against cancers and cardiovascular disease. Common fruits and vegetables are good sources of antioxidants, although in some Mediterranean areas traditional wild greens are responsible for a significant percentage of total dietary antioxidant intake. In the European Prospective Investigation into Cancer and Nutrition cohort of Ragusa (Sicily), a high number of subjects were found to frequently eat wild greens, including Sinapis incana and Sinapis nigra, Diplotaxis erucoides, Cichorium intybus, Asparagus acutifolius, and Borrago officinalis. On the basis of these observations, detailed characterization of single antioxidant components (i.e., polyphenols, carotenoids, chlorophylls, and ascorbic acid) and the TAC of these edible wild traditional plants was performed. The wild plants examined were found to be very rich in antioxidants, such as flavonoids and carotenoids, with high TAC values, suggesting that the importance of these vegetables, not only in the traditional but even in the contemporary diet, needs to be emphasized.     

Influence of cultivation site on sesquiterpene lactone composition of forage chicory (Cichorium intybus L.)

The forage potential of chicory (Cichorium intybus L.) has not been realized in southern West Virginia (WV) because ruminants are reluctant to consume the herbage. Chicory contains bitter sesquiterpene lactones that can adversely impact palatability. This study was undertaken to determine whether sesquiterpene lactone concentrations in chicory grown in southern WV differ from those in chicory grown in central Pennsylvania (PA) where chicory is grazed readily. Herbage was collected in 1997 and 1998 from cultivars Grasslands Puna (Puna), INIA le Lacerta (Lacerta), and Forage Feast established at research sites near State College, PA, and Beckley, WV. The total concentration of sesquiterpene lactones in WV-grown cultivars was 0.58% (dry matter basis) in Puna, 0.59% in Lacerta, and 0.79% in Forage Feast in 1997 and ranged from 1.03 (Lacerta) to 1.52% (Forage Feast) in 1998. In PA-grown cultivars, sesquiterpene lactones represented 0.16 (Puna), 0.18 (Lacerta), and 0.27% (Forage Feast) of the forage dry matter in 1997 and ranged from 0.32 (Lacerta) to 0.55% (Forage Feast) in 1998. Concentrations of lactucin, lactucopicrin, and total sesquiterpene lactones in Forage Feast exceeded those in the other cultivars grown at the same site. The lowest concentrations of lactucopicrin and total sesquiterpene lactones observed among WV-grown cultivars were higher (2-fold or more) than the highest concentrations present in cultivars grown the same year in PA. Mineral analyses of soils from the two cultivation sites indicate that P availability may influence sesquiterpene lactone composition of chicory herbage. Results provide a foundation for future studies of environmental effects on sesquiterpene lactone composition and palatability of chicory herbage.     

Exploration of genetic diversity within Cichoriumendivia and Cichorium intybus with focus on the gene pool of industrial chicory

The present study used 15 simple sequence repeat loci to characterize the genetic diversity of the germplasm that originated the current industrial chicory and to establish the relationships between and inside Cichoriumintybus L. and Cichorium endivia L. Initially we analyzed 19 cultivated C. endivia accessions, 27 wild and 155 cultivated C. intybus accessions distributed among three groups: 83 root chicories, 42 Witloof and 30 leaf chicories. The leaf chicories comprised cultivars corresponding to the Radicchio, Sugarloaf and Catalogne subgroups. The latter has not been previously included in any genetic diversity study. Subsequently, 1297 individuals from the 15 modern root chicory cultivars at the origin of the breeding of the current industrial root chicory cultivars were analyzed. Although the accessions of C. endivia and C. intybus were clearly separated from each other, seven wild C. intybus individuals were genetically closer to C. endivia than to C. intybus, revealing complex genetic interrelationships between these species. The differentiation of C. intybus into three cultivar groups (Witloof, root chicory and leaf chicory) was confirmed. The leaf chicory individuals were divided into three genetic subgroups, corresponding to the Radicchio, Sugarloaf and Catalogne cultivars, thus attesting to the validity of the classification based on morphological factors. Clear differentiation was observed among the Belgian, Polish and Austrian modern industrial root cultivars, but not among the French industrial modern root cultivars. The high phenotypic and genetic variability of the modern industrial root cultivars indicates that this germplasm constitutes a useful gene pool for cultivar improvement and selection.     

Characterization of cider apples on the basis of their fatty acid profiles

In the current study, the fatty acids composition of 30 monovarietal apple juices from six cider apple varieties belonging to two categories was analyzed. The different apple juices were obtained from three consecutive harvests (1997, 1998, and 1999). The fatty acids concentration in apple juice together with chemometric techniques such as principal components analysis (PCA), soft independent modeling of class analogy (SIMCA), and linear discriminant analysis (LDA), allowed us to differentiate apple juices on the basis of the sweet or sharp category to which the cider apple variety belongs. Fatty acids such as the unsaturated oleic and linoleic acids, and saturated caprylic, capric, stearic, and palmitic acids were related to the sweet cider apple category, while pentadecanoic acid is related to the sharp class.     

HPLC-DAD/MS characterization of flavonoids and hydroxycinnamic derivatives in turnip tops (Brassica rapa L. Subsp. sylvestris L.)

Flavonoids and hydroxycinnamic derivatives of turnip tops (Brassica rapa L. subsp. sylvestris L.) were characterized for the first time in four samples from different origins. Turnip tops exhibit a high polyphenols content (ranging from 107 to 191 mg/100 g, fresh weight) and a good antiradical activity, determined with the DPPH* test. After a liquid-liquid extraction and fractionation procedures, most flavonoids (isorhamnetin, kaempferol, and quercetin glycosides) and hydroxycinnamic derivatives were identified by means of HPLC-DAD/MS techniques. Isorhamnetin glycosides were the main flavonoid derivatives, differing from that found in the vegetables belonging to the Brassica oleracea group.