Antioxidant actions and phenolic and vitamin C contents of common Mauritian exotic fruits

Seventeen commonly consumed exotic fruits from Mauritius were analysed for their antioxidant capacity, total phenolics, proanthocyanidins, flavonoids and vitamin C content. Two independent methods were used to evaluate the antioxidant potential of total fruit extracts. The antioxidant activities of the fruits ranged from 1 to 47 µmol Trolox equivalent antioxidant capacity (TEAC) g^?1 fresh weight and from 0.3 to 34 micro/mol g fresh weight (FRAP) g^?1 fresh weight. Total phenolics in the fruits ranged from 118 to 5638 µg g^?1 fresh weight, proanthocyanidins from 7 to 2561 µg g^?1 fresh weight, flavonoids from 21 to 712 µg g^?1 fresh weight and vitamin C content from 8 to 1426 µg g^?1 fresh weight. There were strong correlations between antioxidant activity (assessed by both TEAC and FRAP) and total phenolics and proanthocyanidins. Flavonoids seemed to contribute less to the antioxidant potential of the fruits, while very poor correlations were observed between ascorbate content and antioxidant activity. The highest antioxidant capacities were observed in red and yellow Psidium cattleianum Sabine ‘Chinese guava’, sweet and acid Averrhoa carambola L ‘starfruit’, Syzygium cumini L Skeels ‘jamblon’ and white Psidium guajava L ‘guava’. These fruits were also characterised by high levels of total phenolics. Mauritian exotic fruits are thus a significant source of phenolic antioxidants, which may have potential beneficial effects on health. Copyright © 2003 Society of Chemical Industry     

Antioxidant properties of domesticated and wild Rubus species

The antioxidative capacities of a number of Rubus species of varied pigmentation have been investigated. In addition, total phenol, anthocyanin and ascorbic acid contents have been determined. Two methods to assess the antioxidant potential of fruit juices have been used. The antioxidant capacities of the fruit ranged from 0 to 25.3 µmol Trolox equivalents g⁻¹ (TEAC) or from 190 to 66 000 µmol l⁻¹ ferric reducing antioxidant power (FRAP). Ascorbic acid contributes only minimally to the antioxidant potential of Rubus juices (<10%, TEAC). There are apparent linear relationships between antioxidant capacity (assessed as both TEAC and FRAP) and total phenols (r_xy = 0.6713 and 0.9646 respectively). Also, anthocyanin content has a minor influence on antioxidant capacity (r_xy = 0.3774, TEAC; r_xy = 0.5883, FRAP). The sample with the highest antioxidant capacity (Rubus caucasicus) had the highest phenol content, but only a low percentage was represented by anthocyanins. The present study demonstrates the potential of certain wild Rubus species, notably R caucasicus, for improvement of nutritional value through germplasm enhancement programmes. © 2000 Society of Chemical Industry     

Distribution of 127 edible plant species for antioxidant activities by two assays

Epidemiological studies have demonstrated the protective effects of fruit and vegetable consumption on human health. A total of 150 edible plants representing 127 species were evaluated for Trolox equivalent antioxidant capacity (TEAC) and superoxide scavenging (SOS) activity. Distributions of vegetables for TEAC and SOS were not continuous but highly skewed. TEAC values on a dry weight basis ranged from 0 to 2105 µmol TE g⁻¹ and SOS values ranged from 0 to 6206 µmol ascorbate equivalent (AE) g⁻¹. The majority of vegetables clustered within 200 µmol TE g⁻¹ and 400 µmol AE g⁻¹. Vegetable species were grouped into six classes after natural logarithm transformation of TEAC and SOS values. Most highly consumed vegetables fell in the very low to medium classes. Species in the very high class for both TEAC and SOS included leaves of Cedrela sinensis (Chinese cedar), Oroxylum indicum (Damocles tree), Cassia siamea (cassod tree) and Cassia tora (sickle senna). Edible plants high in antioxidant activity (AOA) were mostly perennial and underutilised crops, while commonly consumed vegetables were generally low in AOA. There is great potential to increase dietary antioxidants and improve human health through consumption of diverse vegetable species, especially those high in AOA. Copyright © 2006 Society of Chemical Industry     

A comparative study on the polyphenolic content,antibacterial activity and antioxidant capacity of different solvent extracts of Brassica oleracea vegetables

Brassica vegetables are rich in polyphenols, flavonoids and glucosinolates. Investigation was undertaken to optimise the best solvents among 60% ethanol, acetone and methanol for the extraction of polyphenols from Brassica vegetables. Furthermore, different properties such as antibacterial activity and antioxidant capacity were also investigated. Results showed that a 60% methanolic extract showed the highest total phenolic content which was 23.6, 20.4 and 18.7 mg gallic acid equivalents (GAE) g^?1 extract for broccoli, Brussels sprouts and white cabbage, respectively. The hydroxybenzoic acid content of various solvent extracts ranged from 5.86 to 8.91 GAE g^?1 extract for broccoli, 2.70 to 5.44 GAE g^?1 extract for Brussels sprouts and 3.69 to 4.86 GAE g^?1 extract for white cabbage, while the hydroxycinnamic acid content ranged from 0.78 to 1.26 chlorogenic acid equivalents (CAE) g^?1 extract for broccoli, 1.41 to 3.45 CAE g^?1 extract for Brussels sprouts and 0.49 to 1.14 CAE g^?1 extract for white cabbage. A concentration‐dependent antioxidative capacity was confirmed for different reactive oxygen species, and moderate antibacterial activity was observed against a number of Gram‐negative and Gram‐positive food spoilage and food pathogenic bacteria. Solvents significantly affected polyphenolic content and its different properties, and the methanol was found to be the best solvent for the extraction of polyphenols from studied Brassica vegetables.     

Evaluation of antioxidant activities of rosehip ethanol extracts in different test systems

Rosehip extracts of 18 samples representing six taxa in the genus Rosa were evaluated for antioxidant activities by use of different test systems. The ferric‐reducing antioxidant power (FRAP) and Trolox‐equivalent antioxidant capacity (TEAC) of the crude extracts ranged from 983.4 to 2187.1 µmol FRAP g⁻¹ dry matter and from 457.2 to 626.2 µmol TEAC g⁻¹ dry matter. The high antioxidant capacity was related to high contents of phytonutrients. The overall mean of antioxidants was 23.23 mg g⁻¹ total carotenoids and 76.26 mg g⁻¹ total phenolics. The phenolic component made a major contribution to the total antioxidant activities in both assays (overall mean was 90.5% and 75.7%), whereas the ascorbate made a minor contribution (8.6% and 16.9%) and the lipophilic component made an even smaller one (0.9% and 7.3%). However, the lipophilic component was the most effective when the comparison was based on the ratio of antioxidant activity to content of antioxidants. The crude extracts exhibited 50.9% (46.6–60.3%) inhibitory effect against the lipid peroxidation induced by 2,2′‐azobis(2,4‐dimethylvaleronitrile) (AMVN) and 85.0% (80.1–90.2%) inhibition in 2,2′‐azobis(2‐amidinopropane)hydrochloride (AAPH) assay at a concentration of 250 µg ml ⁻¹. Ascorbate acted as an antioxidant in both peroxy radical‐induced lipid peroxidations, but as a pro‐oxidant in the metal ion‐induced lipid peroxidation. The crude extracts showed a large inhibitory effect in the ferric ion‐induced lipid peroxidation and caused 83.7% inhibition at a concentration of 25 µg ml ⁻¹ dried rosehip powder. © 2000 Society of Chemical Industry     

Potential bioactive compounds in health promotion from broccoli cultivars grown in Spain

Glucosinolates, phenolic compounds and vitamin C were evaluated in two commercial and 12 experimental cultivars of broccoli (Brassica oleracea L var italica) grown under uniform cultural conditions. The predominant glucosinolates in all broccoli cultivars were 4‐methylsulphinylbutyl glucosinolate (glucoraphanin) and 3‐indolylmethyl glucosinolate (glucobrassicin). Other glucosinolates such as 4‐OH‐glucobrassicin and N‐methoxyglucobrassicin were detected in lower amounts. The total glucosinolate concentration ranged from 3.0 µmol g^?1 dw (dry weight) in Pentathlon (experimental cultivar) to 28.3 µmol g^?1 dw in I‐9905 (experimental cultivar). Flavonoids, caffeic acid derivatives and sinapic acid derivatives were quantified in methanol extracts. The largest content of flavonoids was found in the commercial cultivars Marathon and Lord, around 60 mg kg^?1 fw (fresh weight). The vitamin C content of broccoli ranged from 43.1 mg per 100 g fw in Lord (commercial cultivar) to 146.3 mg per 100 g fw in SG‐4515 (experimental cultivar). © 2002 Society of Chemical Industry     

Survey of levels of cadmium in oysters,mussels, clams and scallops from the Pacific Northwest coast of Canada

Field and retail collections of bivalves from the Pacific Northwest, Canada, were analysed for cadmium concentrations by atomic absorption spectrophotometry (AAS). Both collections of varnish (Nuttallia obscurata) and manila (Venerupis philippinarum) clams contained cadmium concentrations of less than 0.5 µg g^?1, well below international safety guidelines of 1 and 2 µg g^?1 wet weight cadmium for the European and Hong Kong markets, respectively, as well as the 2 µg g^?1 safety guideline set by the Codex Alimentarius Commission (CAC). Cadmium concentrations in retail collections of the Pacific oyster, Crassostrea gigas, were generally above 2 µg g^?1 wet weight (range = 1.5–3.56 µg g^?1). Retail collections of the mussel, Mytilus spp., contained cadmium concentrations below the 2 µg g^?1 wet weight guideline, but not always the 1 µg g^?1 limit (range = 0.15?1.8 µg g^?1). However, field collections of Mytilus spp. contained cadmium concentrations between 0.35 and 4.00 µg g^?1 wet weight, and depending on sampling location, concentrations exceeded the CAC guidelines by more than two-fold. Locations where mussels had high cadmium concentrations correlated with regions that had previously reported high values for cadmium in Pacific oysters (r = 0.65; p < 0.05). Of the various shellfish analysed, the four species of scallops, Chlamys hastata, C. rubida, Crassadoma gigantea, and Patinopecten yessoensis, contained the greatest concentrations of cadmium, in excess of 5 µg g^?1 wet weight (range = 4.97–8.98 µg g^?1) with the greatest concentrations determined for C. gigantea. Cadmium concentrations in shellfish from the Pacific Northwest are greater than values reported for shellfish from other regions of the world and consumers need be aware of Health Canada consumption guidelines for shellfish from this region.     

Quantitative analysis of the isoflavone content and biological growth of soybean (Glycine max L.) at elevated temperature,CO2 level and N application

Effects of ambient and elevated CO₂ levels (360 and 650 µmol mol^?1 respectively), ambient and high (5 °C above ambient) temperatures and their interactions with N application on soybean (Glycine max L.) were studied in 2001. Overall, total isoflavones in whole soybean seeds were highest (1383.0 µg g^?1) in the elevated CO₂ (AE) treatment without N application and lowest (414.1 µg g^?1) in the elevated temperature (EA) treatment with N application. Malonylgenistin (449.2 µg g^?1) and malonyldaidzin (435.9 µg g^?1) concentrations in the AE treatment without N application were highest among the 12 individual isoflavones, while aglycon and acetyl conjugates showed lower concentrations (below 10 µg g^?1) than glucoside and malonyl conjugates in all treatments. Overall, N application had no effect on total isoflavone concentration, while both temperature and CO₂ level had a higher effect on increasing isoflavones, including aglycon and acetyl conjugates (P = 0.001). In the biological growth analysis, total dry weight was highest (100.9 g) in the elevated temperature and CO₂ (EE) treatment with N application, while leaf area was more affected by CO₂ than by temperature and increased with N application. There were larger numbers of pods (99) and seeds (176) per plant in the EE treatment with N application, and generally the AE treatment showed a greater increase in 100‐seed weight (g per 100 seeds) and in pods and seeds per plant than other treatments. Overall, total dry weight was highly affected (P = 0.001) by three main factors, temperature, CO₂ and N application, but the interactions temperature × N and temperature × CO₂× N did not affect total dry weight. Also, total dry weight tended to increase with increasing numbers of pods (r² = 0.93***) and seeds (r² = 0.93***) and larger leaf area (r² = 0.85***). In addition, numbers of pods and seeds were significantly affected (P = 0.01–0.001) by temperature, CO₂ and temperature × CO₂. Generally, elevated CO₂ and temperature did not affect N, P and K concentrations in the seeds but did decrease the concentrations of Ca and Mg, which were increased in the AE treatment. Among the nutrients, Ca and Mg were highly correlated with temperature and CO₂ level. N concentration in the seeds increased with applied N and in particular showed a high increase with elevated temperature and ambient CO₂ (EA treatment). The variation in isoflavones was correlated with temperature (r² = ?0.70**) and CO₂ (r² = 0.67**), while N application was not correlated with isoflavone concentration. Also, Ca (r² = ?0.85***) and Mg (r² = ?0.57*) in the seeds were correlated with variation in isoflavones. This indicated that isoflavones were in higher concentrations under conditions of low temperature and increasing CO₂, which also resulted in low Ca and Mg concentrations in the seeds. The results of this study suggest that the long‐term adaptation of the soybean to growth at elevated CO₂ level and high temperature might potentially increase its isoflavone content, growth and yield. Copyright © 2005 Society of Chemical Industry     

Vegetables antioxidant losses during industrial processing and refrigerated storage

Twenty-five vegetables (artichoke, asparagus, beetroot, broad bean, broccoli, Brussels sprout, carrot, cauliflower, celery, chicory, cucumber, eggplant, endive, garlic, green bean, leek, lettuce, maize, onion, pea, pepper, radish, spinach, Swiss chard and zucchini) were used to evaluate their antioxidant activity. All fresh vegetables studied were able to scavenge lipoperoxyl and hydroxyl radicals. All the vegetables also presented good total capacity antioxidant by TEAC assay except cucumber, endive, carrot and zucchini.Vegetables stored (7 days) in a home refrigerator recorded the same antioxidant activity as fresh samples, except cucumber and zucchini (lipid peroxidation) and broccoli, Brussels sprout and leek (TEAC).Canned vegetables showed a more pronounced loss of antioxidant activity than frozen vegetables compared with fresh vegetables.During the shelf life of the processed vegetables (8 months for frozen and 18 months for canned vegetables), some products showed losses (19–48%) of their lipoperoxyl radical scavenging capacity and total antioxidant activity.     

Characterization of the antioxidant functions of flavonoids and proanthocyanidins in Mauritian black teas

Tea drinking is associated with an improved antioxidant status in vivo which may contribute to the lowering of the risk of certain types of cancer, coronary heart disease and stroke. The polyphenolic bioactive composition and the antioxidant properties of Mauritian commercial black and fresh tea leaves were evaluated. Hot water infusates contained high levels of total phenols, total proanthocyanidins and total flavonoids. The concentrations of individual compounds, (+)-catechin, (−)-epicatechin, (−)-epicatechin 3-gallate, epigallocatechin, (−)-epigallocatechin 3-gallate, gallic acid, and procyanidin dimers B1 and B2 were high. The ferric reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) assays were used to assess the antioxidant potential of tea infusates with the following order of potency: Ouvagalia tea > Buccaneer’s choice > Black Label > Red Label > Extra > Corson > Chartreuse > La Flora > 3-Pavillons. Linear regression analyses indicated high correlation coefficient with total proanthocyanidin (TEAC r = 0.96 and FRAP r = 0.95) and total phenol contents (TEAC r = 0.90 and FRAP r = 0.92) in infusates. Catechins and gallic acid significantly contributed to the overall antioxidant capacity of black tea extracts. In general, the fresh tea leaves had high levels of total phenols, total flavonoids, total proanthocyanidin and exhibited greater antioxidant potentials when compared with black teas. Thus Mauritian black teas and fresh tea leaves can be rich sources of polyphenolic compounds and antioxidants, which may be highly relevant to the maintenance of normal health and disease management, an observation that has led to the commencement of a clinical trial study to assess cardiovascular health in Mauritius.     

Beneficial effect of the unsaponifiable matter from rice bran on oxidative stress in vitro compared with α‐tocopherol

Unsaponifiable matter (UM) was prepared from rice bran using n‐hexane extraction followed by removal of its fatty acid methyl ester with supercritical CO₂ under heat‐stable conditions. The UM was made up of 1% of vitamin E isomers, 28% of γ‐oryzanol and 71% of uncharacterized compounds. The aim of this study was to determine the antioxidant activities of the UM, using α‐tocopherol (α‐T) as a positive control, by measuring the Fe³⁺‐reducing antioxidant power (FRAP), 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH^?) free‐radical‐scavenging property and lipid peroxidation in rat liver microsomes. In addition, the effects of the UM on the tert‐butyl hydroperoxide (t‐BOOH)‐induced cytotoxicity in cultured rat hepatocytes were also investigated. In FRAP assay and DPPH^? free‐radical‐scavenging assay, the results were expressed g^?1α‐T or g^?1 UM. The amount of UM used in lipid peroxidation assay and cytotoxicity assay was the amount required to have equal amounts of total vitamin E isomers in the sample and the control α‐T. The UM, as well as α‐T, exhibited significant antioxidant activities in FRAP, radical‐scavenging and membrane‐lipid oxidation. The FRAP value for total vitamin E isomers in the UM (TVEIUM) was 9.1 times higher than that for α‐T. In terms of their capacities to perform radical‐scavenging and lipid peroxidation, both TVEIUM and α‐T showed similar antioxidant activities. In experiments using cultured rat hepatocytes, the t‐BOOH‐induced lactate dehydrogenase release was significantly inhibited by the addition of 63.5 and 160 µg ml^?1 of TVEIUM treatments (84 and 89%, respectively), and that of 63.5 and 160 µg ml^?1 of α‐T treatment (88 and 93%, respectively). The antioxidant function against oxidative stress of the UM prepared from rice bran may extend its use to being a potential dietary supplement. Copyright © 2004 Society of Chemical Industry     

Plant sterols in vegetables,fruits and berries

The plant sterol contents of the most important vegetables, fruits and berries available in Finland were determined by capillary gas chromatography. The sample preparation procedure included both acid and alkaline hydrolysis to liberate sterols from their conjugates. The plant sterol contents of fresh vegetables ranged from 51 to 370 mg kg^?1 fresh weight (fw) in samples obtained from retail sale. The highest contents (>300 mg kg^?1) were measured in broccoli, Brussels sprouts, cauliflower and dill and the lowest (51 mg kg^?1) in potato. The range of sterol contents on a dry weight (dw) basis was high, 246–4100 mg kg^?1 dw. Considerable variation was also observed when individual samples of some vegetables were compared. Sitosterol was the main sterol (proportion 43–86%) in all vegetables except cucumber and spinach, in which Δ⁷‐sterols dominated. The total sterol contents were in the range 116–228 mg kg^?1 fw in all fresh fruits except avocado, which contained more sterols, 752 mg kg^?1 fw. In fresh berries the corresponding range was 60–279 m kg^?1 fw. The wild berries lingonberry and blueberry were better plant sterol sources than the cultivated berries blackcurrant, redcurrant and strawberry. In fruits and berries the proportion of sitosterol ranged from 61–93% total sterols. On the basis of the results, the contribution of vegetables, fruits and berries to the total average daily plant sterol intake was estimated to be ca 60 mg. © 2003 Society of Chemical Industry     

In vitro accessibility of β‐carotene from cooked Sri Lankan green leafy vegetables and their estimated contribution to vitamin A requirement

Vitamin A deficiency is an important issue for public health in Sri Lanka, where pro‐vitamin A carotenoids from green leafy vegetables provide most of the dietary vitamin A. The objective of this study was to analyse the β‐carotene content of seven types of green leafy vegetables and calculate the contribution of one traditionally cooked portion to the recommended daily allowance (RDA) of retinol. The total amount and in vitro accessibility of β‐carotene were determined using HPLC. The in vitro method simulates the conditions in the human intestinal tract. The all‐trans‐β‐carotene content in the fresh blanched vegetables ranged from 149 µg g^?1 dry weight (DW) in leaves of Alternanthera sessilis (mukunuwanna) to 565 µg g^?1 DW in Amaranthus caudatus (thampala). One portion (100 g) of green leaves cooked without fat (coconut) only contributed from 140 to 180 µg mg^?1 of the recommended daily allowance. A. sessilis, Centella asiatica (gotukola), Spinacea oleracea (nivithi) and A. caudatus, cooked with coconut fat contributed 140–680 µg mg^?1. However, stir‐fried or ‘malluma’ preparations (with coconut products) of Sesbania grandiflora (kathurumurunga) and Manihot esculenta (manioc) may provide more than 1.59–4.37 times the RDA of retinol. These results show that not only the choice of green leaves used but also the addition of fat while cooking is of great importance. Copyright © 2005 Society of Chemical Industry     

Antioxidant activity of the ethanolic extract from the bark of Chamaecyparis obtusa var. formosana

BACKGROUND: Chamaecyparis obtusa var. formosana (Taiwan hinoki) is an endemic conifer in Taiwan and the purpose of this study is to evaluate the antioxidant activity of various fractions obtained from the bark of this plant material. The ethanolic extract of the bark was sequentially separated into three fractions, including n‐hexane, ethyl acetate and ethanol soluble fractions, by liquid–liquid partition. Then the antioxidant activities of crude extract and three fractions along with 13 subfractions obtained from the ethyl acetate (EA) soluble fraction were tested for several antioxidant assays. RESULTS: The total phenolic content of the samples varied from 27.71 to 102.86 mg GAE g^?1 dry weight for fractions, and from 49.94 to 206.46 mg GAE g^?1 for subfractions (where GAE is milligrams of gallic acid per gram of extract). The Trolox equivalent antioxidant capacity (TEAC) ranged from 0.15 to 0.26 mmol L^?1 Trolox equivalents. The EA soluble fraction was found to be the best antioxidant‐rich fraction in terms of DPPH and reducing power assays. With further data analysis it was found that there was a positive correlation between the total phenolic content of extracts and TEAC is R² = 0.61. CONCLUSION: Results from various antioxidant assays showed that the EA fraction possessed strong antioxidant activity. This would provide additional information about the antioxidant activity of bark extract of this plant species. Copyright © 2008 Society of Chemical Industry     

Lycopene content differs among red‐fleshed watermelon cultivars

Lycopene, a carotenoid, has antioxidant properties that may reduce the incidence of certain cancers. Watermelon (Citrullus lanatus (Thunb) Matsum & Nakai) is a natural source of lycopene, with a reported average content of 48.7 µg g^?1 fresh weight based on samples taken from retail produce. This study demonstrated the variability of lycopene content in 11 red‐fleshed watermelon cultivars grown at one location, representing seedless, open‐pollinated and hybrid types, and in commercially shipped hybrid and seedless melons, representing seasonal production periods. Tristimulus colorimeter a* and chroma values were positively correlated with lycopene values, but linear or quadratic regressions of colorimeter data against lycopene values were not significant. Tristimulus colorimeter readings from cut melons were compared to amounts of lycopene extracted from the same melons. Lycopene content varied widely among cultivars, with four cultivars having mean values greater than 65.0 µg g^?1 fresh weight. Seedless types sampled tended to have higher amounts of lycopene (>50.0 µg g^?1 fresh weight) than seeded types. Watermelon lycopene content changed for some cultivars with production season. Published in 2001 for SCI by John Wiley & Sons, Ltd     

Assessment of in vitro antioxidant, antibacterial and immune activation potentials of aqueous and ethanol extracts of Phyllanthus niruri

BACKGROUND: Recently much attention has been paid to biologically active plants because of their low production cost and fewer adverse effects compared with chemical drugs. In the present investigation the bioactivity of Phyllanthus niruri ethanol and aqueous extracts was evaluated in vitro. RESULTS: The ethanol extract of P. niruri showed a high level of flavonoid content (123.9 ± 0.002 mg g^?1), while the aqueous extract showed the highest 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH; IC₅₀6.85 ± 1.80 µmol L^?1) and 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS; 46.44 ± 0.53 µmol L^?1) free radical scavenging activities with high phenol content (376 ± 0.02 mg g^?1) and elevated levels of ferric reducing antioxidant power (FRAP; 23 883 ± 0.019 mmol g^?1) with excellent antibacterial activity against Staphylococcus aureus (20 mm inhibition zone) and Streptococcus agalactiae (12 mm inhibition zone), respectively, in addition to the best immune activation potential of human peripheral blood mononuclear cells (450.5%). CONCLUSIONS: It is clear from our results that both extracts of P. niruri has excellent bioactivity roles via elevated levels of antibacterial, antioxidant and percentage of peripheral blood mononuclear cell proliferation, which could lead to the development of medications for clinical use. Copyright © 2012 Society of Chemical Industry     

Antioxidant capacity and secondary metabolites in four species of Andean tuber crops: native potato (Solanum sp.), mashua (Tropaeolum tuberosum Ruiz & Pavón), Oca (Oxalis tuberosa Molina) and ulluco (Ullucus tuberosus Caldas)

Four species of edible tubers endemic to and domesticated in the Andes, native potato (Solanum sp.), mashua (Tropaeolum tuberosum Ruiz & Pavón), oca (Oxalis tuberosa Molina) and ulluco (Ullucus tuberosus Caldas), were studied for their antioxidant capacity and associated secondary metabolites. The antioxidant capacity was measured using ABTS^? radicals and total phenolics, carotenoids, anthocyanin, betaxanthin and betacyanin content were also characterized. The antioxidant capacity found in the crops studied ranged from 483 to 9800 µg trolox equiv. g^?1, phenolics ranged from 0.41 to 3.37 mg chlorogenic acid equiv. g^?1, anthocyanins ranged from 0.08 to 2.05 mg cyanidin 3‐glucoside g^?1 and carotenoids ranged from 1 to 25 µg β‐carotene g^?1. The content of bioactive compounds was high and variable between crops and within the genotypes studied. In general, mashua tubers showed the highest antioxidant capacity and phenolic, anthocyanin and carotenoid content compared with other crops. Ulluco was the only crop that contained betalains in the acid form of betaxanthins (22–96 µg g^?1) and betacyanins (64 µg g^?1) with no presence of carotenoids or anthocyanins. This is the first publication regarding the antioxidant capacity of and associated secondary metabolites in Andean tubers. This information can be useful in the identification of Andean tubers species and genotypes with potential value as a novel dietary source of antioxidants for food, and also for medicinal use. Copyright © 2006 Society of Chemical Industry     

Intake of essential and non-essential elements from consumption of octopus,cuttlefish and squid

Total concentrations of essential (Cu, Zn, Se and Cr) and non-essential (Hg, Cd, Pb and As) trace elements were measured in the flesh and hepatopancreas of Octopodidae (Eledone moschata, Eledone cirrhosa, Octopus salutii), Sepiidae (Sepia elegans, Sepia orbignyana) and Loliginidae (Illex coindeti, Loligo vulgaris) from the Mediterranean Sea. As expected, the hepatopancreas showed higher metal concentrations than flesh; the only exceptions were Hg and As, which were equally distributed in the two tissues. Regarding the edible portion, the highest toxic metal concentrations were in Octopodidae (Hg: 0.44, Cd: 0.49, Pb: 0.10 µg g^?1 wet weight) and Sepiidae (Hg: 0.27, Cd: 0.50, Pb: 0.12 µg g^?1 wet weight), while Loliginidae tended to accumulate less metal, especially Hg (Hg: 0.11, Cd: 0.30, Pb: 0.05 µg g^?1 wet weight). The other elements showed a heterogeneous distribution among the different cephalopod families. Loliginidae showed the highest Se concentrations (1.18 µg g^?1 wet weight), Octopodidae of Cu (37.37 µg g^?1 wet weight) and Zn (42.00 µg g^?1 wet weight) and Sepiidae of As (61.43 µg g^?1 wet weight), while Cr was uniformly distributed among the various families (0.38–0.43 µg g^?1 wet weight). In these seafoods, the concentrations of essential and non-essential elements were within the prescribed limits set by various authorities, except for Cu and As. Health risks posed by toxic elements to humans via dietary intake of these mollusks were assessed on the basis on Provisional Tolerable Weekly Intake (PTWI), while the estimated intakes of essential elements were compared to Dietary Reference Intakes (RDIs). A 70-g serving of these mollusks was shown to provide a large contribution to Cd intake (0.89 µg kg^?1 body weight), corresponding to 35.6% of PTWI. Concerning the essential elements, the consumption of these mollusks made an important contribution to daily dietary intake of Se, Cu and Zn.     

Phenolics and antioxidative activities in common beans (Phaseolus vulgaris L)

Six bean cultivars grown in southern Manitoba for 2 years were evaluated for variability in yield of millstreams and phenolic constituents. The ethanolic extract of bean cultivars and millstreams was screened for antioxidant activity using the β‐carotene‐linoleate and the 1, 1‐diphenyl‐2‐picrylhydrazyl (DPPH) in vitro model systems. Cultivar was the main source of variation for yield of millstreams, content of phenolic compounds and antioxidant activities. Phenolic compounds in cultivars varied from 3.3 to 16.6 mg catechin equivalent and from 0.15 to 0.32 mg cyanidin‐3‐glucoside equivalent g^?1 bean for total phenolic and anthocyanin contents, respectively. The bean cultivars exhibited antioxidant activity (AA) of 10–46% inhibition of lipid peroxidation in the linoleate and 0.4–1.3 trolox equivalent antioxidant capacities (TEAC) in the DPPH model systems. The hull millstream with maximum concentration of phenolic compounds exhibited the strongest antioxidant activity of 383 µM trolox equivalent g^?1 hull. Total phenolic content, alone or in combination with other phenolic constituents, is a potential candidate as a selection criterion for antioxidant activity in beans. Copyright © 2005 Society of Chemical Industry     

Glucosinolate content of brassica vegetables: Analysis of twenty-four cultivars of calabrese (green sprouting broccoli,Brassica oleracea L. var. botrytis subvar. cymosa Lam.)

The contents of glucosinolates in twenty-four cultivars of calabrese, green sprouting broccoli, have been determined using glucose release and high performance liquid chromatographic methods. The levels of total glucosinolates (range, 42·1–94·5 mg 100 g⁻¹ fresh weight; mean, 62·3 mg 100 g⁻¹ fresh weight) were comparable with those reported previously for cauliflower, but lower than those found in cabbage and, especially, Brussels sprouts. Analysis of the individual components revealed the main species to be 4-methylsulphinylbutyl glucosinolate (glucoraphanin) and, particularly, glucobrassicin and neoglucobrassicin, containing 3-indolylmethyl and 1-methoxy-3-indolylmethyl side chains, respectively. The individual glucosinolate contents of calabrese and cauliflower are compared and differences are considered in the context of biosynthetic pathways. The consequences of these findings for the flavour and biological properties of calabrese are briefly discussed.