Preclinical evaluation of rapeseed, raspberry, and pine bark phenolics for health related effects

Rapeseed, raspberry, and pine bark are promising bioactive sources of plant phenolics selected from among ca. 100 previously screened plant materials for in vitro preclinical evaluation of health related effects. Phenolic extracts and isolated fractions of the selected materials were investigated for antioxidant, antimicrobial, antiinflammatory, and antimutagenic properties as well as for cell permeability. It was shown that rapeseed and pine bark phenolics and raspberry anthocyanins were good or excellent antioxidants toward oxidation of phosphatidylcholine membrane (liposomes), rapeseed oil (crude) phenolics were effective radical scavengers (DPPH test), and both raspberry and pine bark phenolics inhibited LDL oxidation. Rapeseed oil phenolics, principally vinylsyringol, raspberry anthocyanins, and pinoresinol and matairesinol, the principal components of pine bark phenolic isolate, were effective against formation of the proinflammatory mediator, prostaglandin E(2). Raspberry ellagitannins inhibited the growth of Proteus mirabilis and Klebsiella oxytoca. Pine bark and rapeseed had minor effects on the permeability of model drugs in Caco-2 experiments. None of the tested extracts were mutagenic nor toxic to Caco-2 cells or macrophages. Thus, phenolic isolates from rapeseed, raspberry, and pine bark and are safe and bioactive for possible food applications including functional foods intended for health benefit.     

Anthocyanins, phenolics, and antioxidant capacity in diverse small fruits: vaccinium, rubus, and ribes.

Fruits from 107 genotypes of Vaccinium L., Rubus L., and Ribes L., were analyzed for total anthocyanins (ACY), total phenolics (TPH), and antioxidant capacities as determined by oxygen radical absorbing capacity (ORAC) and ferric reducing antioxidant power (FRAP). Fruit size was highly correlated (r = 0.84) with ACY within Vaccinium corymbosum L., but was not correlated to ACY across eight other Vaccinium species, or within 27 blackberry hybrids. Certain Vaccinium and Ribes fruits with pigmented flesh were lower in ACY, TPH, ORAC, and FRAP compared to those values in berries with nonpigmented flesh. ORAC values ranged from 19 to 131 micromol Trolox equivalents/g in Vaccinium, from 13 to 146 in Rubus, and from 17 to 116 in Ribes. Though ACY may indicate TPH, the range observed in ACY/TPH ratios precludes prediction of ACY from TPH and vice versa for a single genotype. In general, TPH was more highly correlated to antioxidant capacity than ACY was. This study demonstrates the wide diversity of phytochemical levels and antioxidant capacities within and across three genera of small fruit.     

Antioxidant activity of isolated ellagitannins from red raspberries and cloudberries

Ellagitannins from red raspberries (Rubus idaeus) and cloudberries (Rubus chamaemorus) were isolated by using column chromatography and preparative HPLC. The berry phenolic isolates consisted of 80% (cloudberry) and of 60% (raspberry) of ellagitannins, with raspberries also containing anthocyanins. The main ellagitannins of both raspberries and cloudberries were identified by ESI-MS to consist of the dimeric sanguiin H-6 and the trimeric lambertianin C. Monomeric ellagitannins such as casuarictin in raspberries and pedunculagin in cloudberries were also found. The antioxidant activity of the berry phenolic isolate, ellagitannin isolate (mixture), ellagitannin main fraction (dimer and trimer), and ellagic acid was studied in bulk and emulsified methyl linoleate, in human low-density lipoprotein in vitro, and the radical scavenging activity was studied in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test. Cloudberry and red raspberry ellagitannins were highly effective as radical scavengers. Berry ellagitannins also showed significant antioxidant activity toward oxidation of both human LDL and methyl linoleate emulsions. However, only weak or moderate antioxidant activity was exhibited by ellagitannins toward oxidation of bulk oil. Thus, ellagitannins contribute significantly to the antioxidant capacity of cloudberries and red raspberries in lipoprotein and lipid emulsion environments, the latter being more relevant for food applications.     

Proanthocyanidin profile and ORAC values of Manitoba berries, chokecherries, and seabuckthorn

Six Manitoba fruits were analyzed for their phytochemical content and antioxidant activity in order to increase their production and marketability. The major proanthocyanidins (flavanols) present in whole fruit, juice, and pulp of strawberry, Saskatoon berry, raspberry, wild blueberry, chokecherry, and seabuckthorn were measured. The extraction and purification were facilitated using flash column chromatography, while separation and identification were accomplished by using HPLC and LC-MS techniques. The total proanthocyanidin contents varied from 275.55 to 504.77 mg/100 g in the whole fruit samples. Raspberry contained the highest content, and seabuckthorn showed the lowest content of total flavanols. The highest concentration of proanthocyanidin in juice was found in Saskatoon berry (1363.34 mg/100 mL) and the lowest value in strawberry (622.60 mg/100 mL). HPLC and LC-MS results indicated that epicatechin was the most abundant flavanol followed by B2 in the berry samples, while no catechin or B1 was detected in these fruits. A series of oligomers and polymers were detected in all samples. The recovery percentage was obtained from the ratio of the unspiked samples to the area of spiked samples. Monomers, dimers, oligomers, and polymers gave recovery ranges of 83-99%. The lipophilic and hydrophilic antioxidant capacities of whole fruit, juice, and pulp extracts were measured by the oxygen radical absorbance capacity (ORAC) procedure. In whole fruits, the ORAC values varied from 135 to 479 mg/100 g TE in the MeOH fraction. The corresponding ORAC values varied from 115.30 to 733.15 mg/100 g for the acetone fraction. In juice, all berries showed the same antioxidant capacity (P > 0.05) (133.0-312.0 mg/100 g) in the MeOH fraction, with the exception of raspberry (603.0 mg/100 g). Overall, MeOH fractions mainly contained monomers and dimers with smaller amounts of oligomers and polymers when compared to the acetone fractions. Acetone fractions mainly contained polymers and some oligomers. Although acetone fractions contained a higher quantity of total proanthocyanidins, their antioxidant capacities were lower than MeOH fractions.     

Effects of the pesticides thiotox,dichlorvos and carbofuran on the test fishMystus vittatus

A quantitative index of synergism, antagonism and additivity has been measured experimentally in the fishMystus vittatus for three pesticides viz. Thiotox (Endosulfan) (T), Dichlorvos (D) and Carbofuran (C). For a combination of two pesticides, the dose of the one pesticide of a pair was fixed at the no-effect level while the dose of the second pesticide was increased until the entire dose response curve was obtained. To evaluate interactions of three pesticides, the previous pair of pesticides was kept fixed at their combined TL_O level, and the third pesticide was increased and again a dose-response curve was obtained. From the results obtained, it is shown that a particular combination could be synergistic, antagonistic or additive, depending on the relative doses employed. In the present study (T + D)/C combination was most synergistic (toxic) in nature while D/T and C/T were least toxic or antagonistic in their effects. However, T/D, (C + T)/D, C/D and D/C combinations were additive in nature. (D + T)/C, (D + C)/T, (T + C)/D and (C + D)/T combinations were found less synergistic in nature than (T + D)/C.     

High-throughput methods to assess lipophilic and hydrophilic antioxidant capacity of food extracts in vitro

Assays comprising three probes for different mechanisms of antioxidant activity in food products have been modified to allow better comparison of the contributions of the different mechanisms to antioxidant capacity (AOC). Incorporation of a common format for oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP), and iron(II) chelating activity (ICA) assays using 96-well microplates provides a comprehensive and high-throughput assessment of the antioxidant capacity of food extracts. The methods have been optimized for aqueous extracts and validated in terms of limit of quantification (LoQ), linearity, and precision (repeatability and intermediate reproducibility). In addition, FRAP and ORAC assays have been validated to assess AOC for lipophilic extracts. The relative standard deviation of repeatability of the methods ranges from 1.2 to 6.9%, which is generally considered to be acceptable for analytical measurement of AOC by in vitro methods. Radical scavenging capacity, reducing capacity, and iron chelating properties of olive mill wastewaters (OMWW), oregano, and parsley were assessed using the validated methods. OMWW showed the highest radical scavenging and reducing capacities, determined by ORAC and FRAP assays, respectively, followed by oregano and parsley. The ability to chelate Fe (2+) was, in decreasing order of activity ( p > 0.05) parsley congruent with oregano > OMWW. Total phenol content, determined by the Folin-Ciocalteu method, correlated to the radical scavenging and reducing capacities of the samples but not to their chelating properties. Results showed that the optimized high-throughput methods provided a comprehensive and precise determination of the AOC of lipophilic and hydrophilic food extracts in vitro.     

蚕豆发芽过程中蛋白质和抗氧化能力的变化

为更好地开发利用蚕豆资源,研究蚕豆发芽过程中蛋白质及蛋白抗氧化能力的变化规律,采用凯氏定氮法测定发芽蚕豆的蛋白质含量,采用氨基酸分析仪测定氨基酸组分含量,运用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)技术观察发芽蚕豆蛋白组成的变化,通过测定发芽蚕豆蛋白的1,1-二苯基-2-三硝基苯肼(DPPH)自由基和2,2'-联氮双-(3-乙基苯并噻唑啉-6-磺酸)二铵盐(ABTS)自由基的清除能力分析其抗氧化能力。结果表明,蚕豆发芽过程中蛋白和氨基酸含量升高,促进部分蚕豆蛋白由大分子量转化分解成小分子量,提高了蚕豆蛋白的抗氧化能力,在蚕豆发芽第9天时蛋白质含量达到34.1 g·100g^-1、氨基酸含量为29.16 g·100g^-1,均达到最大值,蚕豆蛋白的自由基清除能力达到最强。综上,蚕豆的发芽过程可以增加蚕豆的营养物质成分含量,增强蚕豆的抗氧化能力。本研究结果为蚕豆蛋白、蚕豆芽等功能食品的开发利用提供了参考依据。     

Fast and simple method for the simultaneous evaluation of the capacity and efficiency of food antioxidants in trapping peroxyl radicals in an intestinal model system

A simple oxygraphic method, for which the theoretical and experimental bases have been recently revised, has been successfully applied to evaluate the peroxyl radical chain-breaking characteristics of some typical food antioxidants in micelle systems, among which is a system that reproduces conditions present in the upper part of the digestive tract, where the absorption and digestion of lipids occur. This method permits one to obtain from a single experimental run the peroxyl radical trapping capacity (PRTC, that is, the number of moles of peroxyl radicals trapped by a given amount of food), the peroxyl radical trapping efficiency (PRTE, that is, the reciprocal of the amount of food that reduces to half the steady-state concentration of peroxyl radicals), and the half-life of the antioxidant ( t(1/2)) when only a small fraction of peroxyl radicals reacts with the antioxidants present in foods. Examples of application of the method to various types of foodstuffs have been reported, assessing the general validity of the method in the simple and fast evaluation of the above-reported fundamental antioxidant characteristics of foods.     

Lipophilic and hydrophilic antioxidant capacities of common foods in the United States

Both lipophilic and hydrophilic antioxidant capacities were determined using the oxygen radical absorbance capacity (ORAC(FL)) assay with fluorescein as the fluorescent probe and 2,2'-azobis(2-amidinopropane) dihydrochloride as a peroxyl radical generator on over 100 different kinds of foods, including fruits, vegetables, nuts, dried fruits, spices, cereals, infant, and other foods. Most of the foods were collected from four different regions and during two different seasons in U.S. markets. Total phenolics of each sample were also measured using the Folin-Ciocalteu reagent. Hydrophilic ORAC(FL) values (H-ORAC(FL)) ranged from 0.87 to 2641 micromol of Trolox equivalents (TE)/g among all of the foods, whereas lipophilic ORAC(FL) values (L-ORAC(FL)) ranged from 0.07 to 1611 micromol of TE/g. Generally, L-ORAC(FL) values were <10% of the H-ORAC(FL) values except for a very few samples. Total antioxidant capacity was calculated by combining L-ORAC(FL) and H-ORAC(FL). Differences of ORAC(FL) values in fruits and vegetables from different seasons and regions were relatively large for some foods but could not be analyzed in detail because of the sampling scheme. Two different processing methods, cooking and peeling, were used on selected foods to evaluate the impact of processing on ORAC(FL). The data demonstrated that processing can have significant effects on ORAC(FL). Considering all of the foods analyzed, the relationship between TP and H-ORAC(FL) showed a very weak correlation. Total hydrophilic and lipophilic antioxidant capacity intakes were calculated to be 5558 and 166 micromol of TE/day, respectively, on the basis of data from the USDA Continuing Survey of Food Intakes by Individuals (1994-1996).     

Antioxidant activity and polyphenol and procyanidin contents of selected commercially available cocoa-containing and chocolate products in the United States

In the United States, commercially available foods, including cocoa and chocolate, are being marketed with statements referring to the level of antioxidant activity and polyphenols. For cocoa-containing foods, there has been no comprehensive survey of the content of these and other chemistries. A survey of cocoa and chocolate-containing products marketed in the United States was conducted to determine antioxidant activity and polyphenol and procyanidin contents. Commercially available samples consisted of the top market share products in each of the following six categories: natural cocoa, unsweetened baking chocolate, dark chocolate, semisweet baking chips, milk chocolate, and chocolate syrup. Composite samples were characterized using four different methods: oxygen radical absorbance capacity (ORAC), vitamin C equivalence antioxidant capacity (VCEAC), total polyphenols, and procyanidins. All composite lots were further characterized for percent nonfat cocoa solids (NFCS) and percent fat. Natural cocoas had the highest levels of antioxidant activities, total polyphenols, and procyanidins followed by baking chocolates, dark chocolates and baking chips, and finally milk chocolate and syrups. The results showed a strong linear correlation between NFCS and ORAC (R (2) = 0.9849), total polyphenols (R (2) = 0.9793), and procyanidins (R (2) = 0.946), respectively. On the basis of principal component analysis, 81.4% of the sample set was associated with NFCS, antioxidant activity, total polyphenols, and procyanidins. The results indicated that, regardless of the product category, NFCS were the primary factor contributing to the level of cocoa antioxidants in the products tested. Results further suggested that differences in cocoa bean blends and processing, with the possible exception of Dutching, are minor factors in determining the level of antioxidants in commercially available cocoa-containing products in the United States.     

Assessment of the antioxidant potential of scotch whiskeys by electron spin resonance spectroscopy: relationship to hydroxyl-containing aromatic components.

Electron spin resonance (ESR) spectroscopy has been used to assess the antioxidant capacity of eight Scotch whiskeys by measuring the extent by which the original spirits, or pyridine solutions of their residues, reduced Fremy's radical or galvinoxyl radical. All whiskeys displayed antioxidant activity greater than that of a 0.2 mM solution of Trolox in the Fremy's assay and of a 0.1 mM solution of quercetin in the galvinoxyl assay. The relative antioxidant capacities determined according to the two assays were highly correlated and strongly related to the total phenol content as determined by using the Folin-Ciocalteu method. Activity was a consequence of maturation in oak casks with the "newmake" spirit showing no effect. Of 10 aromatic constituents analyzed, activity was most strongly correlated with ellagic acid and gallic acid in both assays. The reductive capacities of four major phenolics were determined, which, in summation, accounted for 31-53% of the total antioxidant activity of the whiskeys. There was no evidence for synergistic interaction between the phenols investigated.     

Scavenging capacity of berry crops on superoxide radicals, hydrogen peroxide, hydroxyl radicals, and singlet oxygen

The antioxidant activities against superoxide radicals (O(2)(*)(-)), hydrogen peroxide (H(2)O(2)), hydroxyl radicals (OH(*)), and singlet oxygen ('O(2)) was evaluated in fruit juice from different cultivars of thornless blackberries (Rubus sp.), blueberries (Vaccinium spp.), cranberries (Vaccinium macrocarpon Aiton), raspberries (Rubus idaeus L. and Rubus occidentalis L.), and strawberries (Fragaria x ananassa Duch.). Among the different cultivars, juice of 'Hull Thornless' blackberry, 'Earliglow' strawberry, 'Early Black' cranberry, 'Jewel' raspberry, and 'Elliot' blueberry had the highest antioxidant capacity against superoxide radicals (O(2)(*)(-)), hydrogen peroxide (H(2)O(2)), hydroxyl radicals (OH(*)), and singlet oxygen ('O(2)). In general, blackberries had the highest antioxidant capacity inhibition of O(2)(*)(-), H(2)O(2), and OH(*). Strawberry was second best in the antioxidant capacity assay for these same free radicals. With regard to 'O(2) scavenging activity, strawberry had the highest value, while blackberry was second. Cranberries had the lowest inhibition of H(2)O(2) activity. Meanwhile, blueberries had the lowest antioxidant capacity against OH(*) and 'O(2). There were interesting and marked differences among the different antioxidants in their abilities to scavenge different reactive oxygen species. beta-Carotene had by far the highest scavenging activity against 'O(2) but had absolutely no effect on H(2)O(2). Ascorbic acid was the best at inhibiting H(2)O(2) free radical activity. For OH(*), there was a wide range of scavenging capacities from a high of 15.3% with alpha-tocopherol to a low of 0.88% with ascorbic acid. Glutathione had higher O(2)(*)(-) scavenging capacity compared to the other antioxidants.     

EFFECTS OF CARBONIZED CHICKEN MANURE ON THE GROWTH,NODULATION, YIELD,NITROGEN AND PHOSPHORUS CONTENTS OF FOUR GRAIN LEGUMES

The effects of carbonized chicken manure (CCM) on the growth, nodulation, yield, nitrogen (N) and phosphorus (P) contents of four grain legumes (soybean, cowpea, common bean and adzuki bean) were evaluated in a greenhouse experiment. Carbonized chicken manure produced from chicken manure dried in a furnace at 450°C was used in this experiment. The manure was incorporated into the sandy loam soil of each grain legume at two rates (0 kg N ha^?1 and 100 kg N ha^?1) three weeks before sowing. Growth, nodulation and total biomass N and P were evaluated at peak flowering stage of growth. The CCM showed positive effects on nodule number and weight of soybean and cowpea while it depressed nodule number in adzuki bean. Biomass total N content of soybean and cowpea increased with CCM supply while it decreased in adzuki bean. Biomass and seed total P content of soybean, cowpea and adzuki bean all increased in response to CCM application. Soybean and cowpea seed yields increased by 27% and 43% respectively in response to CCM supply. There was a strong positive correlation between seed P content and seed yield of soybean which indicates the importance of elemental P to soybean seed yield. No such phenomenon was observed in adzuki bean. A strong positive correlation was also observed between seed total N content and seed yield of the grain legumes. The results indicate that although common bean had the highest biomass total P content at peak flowering stage both vegetative and reproductive growth were poor due to the unsuitably high day/night temperatures in the greenhouse. Application of CCM slightly depressed yield of adzuki bean due to the reduction in the number of pods per pot and the 100 seed weight. This study shows that CCM is a good source of N and P for the growth, nodulation and yield of some grain legumes particularly soybean and cowpea.     

Antiradical efficiency of Maillard reaction mixtures in a hydrophilic media

The Maillard reaction (MR) has a clear impact in food science, nutrition, and medical research. Free radical scavenging capacities of several MR mixtures made from single combinations of glucose or lactose and amino acids (gly, his, lys, trp, met, and cys) were evaluated by using the N,N-dimethyl-p-phenylenediamine radical cation assay. Medium-roasted coffee brew was used as reference of a thermally processed food. A novel approach has been applied in order to get more information about the kinetic behavior of the radical scavenging properties of MR mixtures in a watery environment. Antiradical efficiency (AE) concept has been applied, and it takes into consideration the reaction time, apart from the amount of antioxidant necessary to decrease by 50% the radical initial concentration (EC(50)). Cysteine and histidine reveal as powerful amino acids to exert a high AE in the MR mixtures. No relationship between AE parameter and browning was observed.     

Antioxidant capacity and other bioactivities of the freeze-dried Amazonian palm berry, Euterpe oleraceae mart. (acai)

The fruit of Euterpe oleraceae, commonly known as acai, has been demonstrated to exhibit significantly high antioxidant capacity in vitro, especially for superoxide and peroxyl scavenging, and, therefore, may have possible health benefits. In this study, the antioxidant capacities of freeze-dried acai fruit pulp/skin powder (OptiAcai) were evaluated by different assays with various free radical sources. It was found to have exceptional activity against superoxide in the superoxide scavenging (SOD) assay, the highest of any food reported to date against the peroxyl radical as measured by the oxygen radical absorbance capacity assay with fluorescein as the fluorescent probe (ORACFL), and mild activity against both the peroxynitrite and hydroxyl radical by the peroxynitrite averting capacity (NORAC) and hydroxyl radical averting capacity (HORAC) assays, respectively. The SOD of acai was 1614 units/g, an extremely high scavenging capacity for O2*-, by far the highest of any fruit or vegetable tested to date. Total phenolics were also tested as comparison. In the total antioxidant (TAO) assay, antioxidants in acai were differentiated into "slow-acting" and "fast-acting" components. An assay measuring inhibition of reactive oxygen species (ROS) formation in freshly purified human neutrophils showed that antioxidants in acai are able to enter human cells in a fully functional form and to perform an oxygen quenching function at very low doses. Furthermore, other bioactivities related to anti-inflammation and immune functions were also investigated. Acai was found to be a potential cyclooxygenase (COX)-1 and COX-2 inhibitor. It also showed a weak effect on lipopolysaccharide (LPS)-induced nitric oxide but no effect on either lymphocyte proliferation and phagocytic capacity.     

Phytic acid, phytase, minerals, and antioxidant activity in Canadian dry bean ( Phaseolus vulgaris L.) cultivars

Ten bean cultivars grown in southern Manitoba in 2006 were evaluated for variability in phytate, phenolic, and mineral contents, phytase activity, and antioxidant properties to elucidate the relationship of these components. Phytic acid content and phytase activity varied significantly among cultivars and market classes, ranging from 16.7 to 25.1 g/kg and from 224 to 361 phytase activity unit/kg of sample, respectively. The bean cultivars with total phenolic content ranging from 2.2 to 5.6 g of catechin equiv/kg of sample exhibited significant variation in antioxidant capacity [1.6-11.2 microM Trolox equiv (TE)/g of dry matter] and peroxyl radical scavenging activity (72-158 microM TE/g) using photochemiluminescence and fluorescence assays, respectively. Multivariate data analysis performed on 22 components analyzed in this study using principal component analysis and cluster methods demonstrate that differences in phytase, antioxidant activity, mineral contents, and bioavailability are much larger within market class than among bean cultivars.     

Chemical compositions, antioxidant capacities, and antiproliferative activities of selected fruit seed flours

Seed flours from black raspberry, red raspberry, blueberry, cranberry, pinot noir grape, and chardonnay grape were examined for their total fat content, fatty acid composition, total phenolic content (TPC), total anthocyanin content (TAC), radical scavenging capacities against the peroxyl (ORAC) and stable DPPH radicals, chelating capacity against Fe(2+), and antiproliferative activities using the HT-29 colon cancer cell line. Significant levels of fat were detected in the fruit seed flours and their fatty acid profiles may differ from those of the respective seed oils. Cranberry seed flour had the highest level of alpha-linolenic acid (30.9 g/100 g fat) and the lowest ratio of n-6/n-3 fatty acids (1.2/1). The ORAC value of the chardonnay seed flour was 1076.4 Trolox equivalents mumol/g flour, and its TPC was 186.3 mg gallic acid equivalents/g flour. These values were 3-12 times higher than the other tested fruit seed flours. Furthermore, the ORAC value was significantly correlated to the TPC under the experimental conditions (P < 0.05). These fruit seed flours also differed in their TAC values and Fe(2+)-chelating capacities. In addition, black raspberry, cranberry, and chardonnay grape seed flour extracts were evaluated for their antiproliferative effects using HT-29 colon cancer cells. All three tested seed flour extracts significant inhibited HT-29 cell proliferation. The data from this study suggest the potential of developing the value-added use of these fruit seed flours as dietary sources of natural antioxidants and antiproliferative agents for optimal human health.     

Screening of foods containing proanthocyanidins and their structural characterization using LC-MS/MS and thiolytic degradation

A normal-phase HPLC-MS/MS method was applied to screen for proanthocyanidins in 88 different kinds of foods. Thirty-nine foods were found to contain proanthocyanidins. These foods include 19 kinds of fruits, eight cereals/beans, seven nuts, two beverages, two spices, and one vegetable. Twenty-five kinds of foods were found to contain both oligomeric (DP 10), and the other 14 foods contained only oligomers. Procyanidins with B-type linkages were detected as the only components in 21 foods and also as principal components in the others. Propelargonidins were identified in pinto bean, raspberry, strawberry, and almond, etc. Plum, avocado, peanut, curry, and cinnamon were identified as potential sources of A-type proanthocyanidins in addition to cranberry. Thiolytic degradation and MS/MS analyses indicated that the A-type linkages are present as a terminal unit in plum or between the extension units in curry, cinnamon, and avocado, whereas A-type linkages exist at both positions in cranberry and peanut.     

Toxicity interaction of metals (Ag, Cu, Hg, Zn) to urease and dehydrogenase activities in soils

A study of the individual and mixture toxicities of the trace metals Ag, Cu, Hg, Zn to the soil enzymes dehydrogenase and urease was undertaken. An agricultural soil and a sandy forest soil were spiked with metal salts, individually and in combinations. The anion additions to the various treatments and controls were normalized for added anions using Ca salts. The soils were then left to equilibrate and leached to reduce the excess metals and anions. Total and dissolved metal concentrations were measured concurrently in order to consider the effect of soil chemistry on the enzyme activities. Dose-response relationships for total soil metals and soil solution metals were estimated for each metal separately following a log-logistic curve fitting. Ag and Hg were the most efficient metals to reduce soil enzyme activities. The Bliss independence model was used to predict the toxicity of metal combinations. The enzyme responses in relation to the total soil metal combinations were synergistic for the agricultural soil and antagonistic for the forest soil; possibly as a result of a higher organic matter content and higher pH in the latter soil. Enzyme activities expressed in relation to the dissolved metal concentrations were more variable than against the total metal contents and consequently we observed both synergistic and antagonistic interactions.     

Antioxidant activity of oregano, parsley, and olive mill wastewaters in bulk oils and oil-in-water emulsions enriched in fish oil

The antioxidant activity of oregano, parsley, olive mill wastewaters (OMWW), Trolox, and ethylenediaminetetraacetic acid (EDTA) was evaluated in bulk oils and oil-in-water (o/w) emulsions enriched with 5% tuna oil by monitoring the formation of hydroperoxides, hexanal, and t-t-2,4-heptadienal in samples stored at 37 degrees C for 14 days. In bulk oil, the order of antioxidant activity was, in decreasing order (p < 0.05), OMWW > oregano > parsley > EDTA > Trolox. The antioxidant activity in o/w emulsion followed the same order except that EDTA was as efficient an antioxidant as OMWW. In addition, the total phenolic content, the radical scavenging properties, the reducing capacity, and the iron chelating activity of OMWW, parsley, and oregano extracts were determined by the Folin-Ciocalteau, oxygen radical absorbance capacity, ferric reducing antioxidant power, and iron(II) chelating activity assays, respectively. The antioxidant activity of OMWW, parsley, and oregano in food systems was related to their total phenolic content and radical scavenging capacity but not to their ability to chelate iron in vitro. OMWW was identified as a promising source of antioxidants to retard lipid oxidation in fish oil-enriched food products.