Photochemiluminescence Method Research Articles

Antioxidant Activity of some Nutraceuticals Based on Romanian Black and Red Fruits Mixed Extracts

With content rich in polyphenols, carotenoids vitamins, minerals and many other bioactive compounds, fruits extracts from Morus nigra L. – black mulberry (blackberry) from Moraceae family, Cerasus avium (syn. Prunus avium) Moench. - bitter cherry from Rosaceae family, Cornus mas L. – cornelian cherry from Cornaceae family, may be useful as a supplementary treatment and especially in preventing many diseases which arise from action of oxidative stress. The aim of this paper is to obtain selected syrups with an increased antioxidant activity based on a mixture of fluids extracts from Morus nigra L. , Cerasus avium (syn. Prunus avium) Moench. and Cornus mas L. indigenous Romanian fruits. Fluid extracts were obtained using different extraction methods (maceration, reflux) and solvents (ethylic alcohol 40% and 70%). The obtained fluid extracts were mixed in different molar ratio and analysed for their physical-chemical properties, total polyphenols assay (Folin–Ciocalteu assay) and total antioxidative capacity by photochemiluminescence method (ACL, Analytik Jena AG procedure). The selected mixed fluid extracts with greatest content of polyphenols and antioxidant activity were used for syrups obtaining. The new obtained syrups were analysed for their physical-chemical properties (appearance, pH and relative density), polyphenols content and total antioxidative capacity. Preliminary results emphasize that syrups with highest antioxidant activity correlated with the polyphenols content would represent a possible new stimulating nutraceuticals that could be used in oxidative stress associated to different diseases. DOI: 10.5901/ajis.2015.v4n1s2p199

Bioactive compounds in potatoes: Accumulation under drought stress conditions

Background: Potato (Solanum tuberosum) is a valuable source of bioactive compounds. Besides starch, crude fibre, amino acids (AAS), vitamins and minerals, the tubers contain diverse phenolic compounds. These phenolics and AAS confer anti-oxidant protection against reactive oxygen species, tissue damage, and diseases like atherosclerosis, renal failure, diabetes mellitus, and cancer. Climate change and drought stress may become a major risk for crop production worldwide, resulting in reduced access for those who depend on the nutritional value of this staple crop.Objective: The aim of this study is to determine the effect of drought stress on water, lipid soluble antioxidants, anthocyanins (Ac), soluble phenols, proteins, free AAS, peroxidase (POD) and lipid acyl hydrolase activity (LAH) in tuber tissue.Methods: The study was carried out on three potato genotypes comprising one yellow-fleshed cultivar and two purple breeding clones. The plants were grown in pots (from April to September) in a glasshouse with sufficient water supply and under drought stress conditions. After harvest, the tubers of both variants were analysed for antioxidants measured as ascorbic acid (ACE) and Trolox equivalent (TXE) using a photo-chemiluminescent method. Amounts of anthocyanins (Ac), soluble phenols, proteins, as well as POD and LAH activities were analysed using a UV photometer. Finally, free AAS were measured by HPLC.Results: The results revealed that drought stress significantly reduces tuber yield, but has no significant effect on antioxidants, Ac, soluble phenols and POD. Drought stress significantly increased the levels of soluble protein (P < 0.0001) and LAH (P < 0.001). Also, total amounts of Functional Foods in Health and Disease 2015; 5(3): 108-116 Page 109 of 116 free AAS were higher in the drought stressed tubers (+34.2%, on average) than in the tubers grown with a sufficient water supply. Above all, proline was elevated due to drought stress.Key words: anthocyanins, antioxidants, free amino acids, phenols, proteins, tuber quality

Development of a new measurement method to determine plant antioxidant status


 The antioxidant capacity of 12 cultivar that were harvested in 2014, were determined by FRAP (Ferric Reducing Ability of Plasma), DPPH (1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity) TEAC (Trolox Equivalent Antioxidant Capacity) and photochemiluminescence method. In sour cherry, the most antioxidant effects of natural bioactive compounds are anthocyanins. Our results show that the photochemiluminescence method is the most suitable to determine the antioxidant capacity of red soft fruits and tart cherries

Phenolic content and antioxidant capacity in algal food products.

The study objective was to investigate total phenolic content using Folin-Ciocalteu’s method, to assess nine phenols by HPLC, to determine antioxidant capacity of the water soluble compounds (ACW) by a photochemiluminescence method, and to calculate the correlation coefficients in commercial algal food products from brown (Laminaria japonica, Eisenia bicyclis, Hizikia fusiformis, Undaria pinnatifida) and red (Porphyra tenera, Palmaria palmata) seaweed, green freshwater algae (Chlorella pyrenoidosa), and cyanobacteria (Spirulina platensis). HPLC analysis showed that the most abundant phenolic compound was epicatechin. From spectrophotometry and ACW determination it was evident that brown seaweed Eisenia bicyclis was the sample with the highest phenolic and ACW values (193 mg·g−1 GAE; 7.53 µmol AA·g−1, respectively). A linear relationship existed between ACW and phenolic contents (r = 0.99). Some algal products seem to be promising functional foods rich in polyphenols.

Random amplified polymorphic DNA (RAPD) fingerprint and antioxidants profile as markers for Tropea red onion (Allium cepa L.) authenticity

Random amplified polymorphic DNA (RAPD) and chemotype analyses were applied to characterise Tropea red onion (Allium cepa L.), a typical Italian variety that is cultivated in specific areas of Calabria. Seven Tropea red onion samples and three commercial cultivars of different coloured onions were evaluated. Amplification of genomic DNA using random primers highlighted a good clustering differentiating Tropea red onion cultivar from commercial reference samples used in this study. The total antioxidant activity and the content of quercetin-3,4′-O-diglucoside (3,4′Qdg) and quercetin-4′-O-monoglucoside (4′Qmg) were measured using photochemiluminescence method (Photochem®) and capillary electrophoresis, both very interesting because of their very short measuring times. The difference in antioxidant activity and quercetin contents between Tropea red onion and commercial sample and also the difference within Tropea cultivar suggested that the nutrient composition did not depend only on particular genetic characters but was probably connected to the intrinsic pedological soil and climate features.

Antioxidant activity measurement of oleoresin from rosemary and sage

The antioxidant activity of oleoresin from rosemary (Rosmarinus officinalis L.) (ROSM) and sage (Salvia officinalis L.) (SAG) was evaluated using photochemiluminescent method (PCL assay), spectrophotometric method based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and Rancimat test. Using PCL assay, the antioxidant content of lipid (ACL) soluble compound in the extracts was quantified (μmol Trolox equivalents/g extract). Rancimat test was used to evaluate the induction period (IP) of sunflower oil blended with ROSM and SAG at 500 and 1000mg/kg under elevated temperature (110°C). The IP was used to determine the oxidative stability index (OSI) and percentage antioxidant activity (%AA). In addition, the phenolic characterization of extracts was performed using ultra performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) which suggested that phenolic diterpenes could be the major antioxidant compounds. The EC50 value obtained from PCL and DPPH assays were significantly correlated (r=0.997, p<0.01). The SAG showed significantly (p<0.05) higher antioxidant activity than ROSM in all the tested methods. The OSI and %AA of ROSM and SAG blended oil was significantly higher (p<0.05) than the control sunflower oil sample. In conclusion, the PCL and Rancimat test were successfully used for direct and dependable monitoring of antioxidant activity and intended as the alternative to DPPH assay for industrial application.

Use of photochemiluminescence for the determination of antioxidant activities of carotenoids and antioxidant capacities of selected tomato products.

The purpose of this study was to compare the antioxidant activity of carotenoids to that of α-tocopherol by using a photochemiluminescence method (PCL). Comparisons to results obtained by using other established methods (α-TEAC, FRAP, DPPH, LPSC) were carried out. A relationship between the chemical structure of carotenoids and their antioxidant activity could be discussed. The number of conjugated double bonds and functional groups had a positive influence. Additionally, the lipophilic antioxidant capacities of selected tomato products were analyzed using PCL and α-TEAC. HPLC was used to identify and quantify contents of carotenoids, tocopherols, and tocotrienols. The raw material fresh tomatoes had the lowest antioxidant effect in both assays due to the lower carotenoid content. Tomato ketchup had the highest AOC in PCL, and tomato puree, in α-TEAC. The antioxidant capacities were mainly dependent on the water content of the samples. Furthermore, a concentration-dependent effect could be observed in both assays.

Sour cherry as a functional food

The antioxidant capacity of ’Debreceni bőtermő’, ’Újfehértói fürtös’ and ’Érdi bőtermő’ cultivars were determined by FRAP (Ferric Reducing Ability of Plasma), DPPH (1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity) and photochemiluminescence method. In sour cherry, the most antioxidant effects of natural bioactive compounds are anthocyanins. Our results show that the photochemiluminescence method out of applied assays is ratheris suitable to determine the antioxidant capacity of red soft fruits and tart cherries. The correlation is good between the determined anthocyanin concent by this technic and pH-differential spectrophotometry. However, both FRAP and DPPH assays are inaccurate.&#x0D; The anthocyanin composition of ’Debreceni bőtermő’, ’Újfehértói fürtös’ and ’Érdi bőtermő’ ’Csengődi csokros’ sour cherry varieties were analised. There are big differences between the accumulation of anthocyanan compounds of cultivars. ’Csengődi csokros’ produce melatonin in large quantity. On the evidence of the results, we can say that the hungarian sour cherry cultivars are suitable for functional food development.

Blood Pressure and Lipid Lowering Effects of Nigella sativa Seeds and Honey Mixture

The aim of this study was to investigate the effect(s) of a mixture ofNigella sativaseeds (N. sativa; black cumin or fennel) and honey on (i) the modulation of cardiovascular disease (CVD) risks among hypercholesterolemic and healthy subjects; and (ii) to assess the lipid-soluble antioxidants capacity of samples using the photochemiluminescence (PCL) method. Sixty-five subjects, aged twenty-five to fifty-eight, were enrolledand assigned to three groups. Two groups of healthy andhypercholesterolemic subjects were supplemented with N. sativa seeds and honey at 50 mg/kg (body weight) daily for three months. The third group served as control (healthy subjects without supplementation). Fasting blood samples were taken at baseline and again after three months of supplementation to measure (i) total cholesterol (TC), (ii) triglycerides (TG), (iii) low density lipoprotein-cholesterol (LDL-c), (iv) high density lipoprotein-cholesterol (HDL-c), (v) blood glucose, and (vi) hemoglobin concentrations. The findings were significant (p  0.05),indicatingthat N. sativa seeds mixed with honey had hypolipidemic, antiobesity and hypotensive effects.Results showed significant reductions in TG (20.1%), TC:HDL-c (12.3%),accompanied by increased HDL-c (15.0%) among healthy subjects.Supplementation also significantly decreased TC (6.2%), TG (13.3%), TC:HDL-c (19.5%),with increased HDL-c (8.4%) in the hypercholesterolemic group. Furthermore, there were significant reductions in body weight, body mass index and body fat by 2.3%, 2.2%, 4.5%, and by 1.8%, 1.9%, 4.5% in healthy and hypercholesterolemic subjects, respectively. Blood pressureslowering werealso observed in hypercholesterolemic subjects with significant reductions in systolic blood pressure (3.9%) and diastolic blood pressure (5.5%). There were no significant effectsfromsupplementation on blood glucose or hemoglobin concentrations. It is postulated that the positive effects observed may be due to antioxidant activity. The combination of of N. sativa seeds with honey showed higher synergistic effectswhen compared withsupplementation ofN. sativa seeds or honey on their own. Overall, these findings suggest that a mixture of N. sativa seeds with honey hasbeneficial effects in loweringthe citedrisk indicators for cardiovascular disease as a natural source of antioxidant activity; thus aidingthe maintainence of health bylowering CVD risk factors.

Comparison of methods for evaluation of the antioxidant capacity and phenolic compounds in common spices

The present study investigates the antioxidant capacity (AC) of ethanol and ethanol/water (1:1, v/v) extracts of selected spices, using cyclic voltammetry (CV), spectrophotometric and photochemiluminescence (PCL) methods. The ABTS test was used for the measurement of the scavenging capacity of the extracts against 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical cations whilst a photochemiluminescence technique was employed to measure the scavenging capacity against superoxide anion radicals (O2−). The cyclic voltammetry (CV) method provided the reducing capacity values of spices. The total phenolics (TPC) and total flavonoids (TF) were determined in both types of spice extracts.With the exception of vanilla, ethanol/water (1:1, v/v) was a better extraction solvent of TPC and TF in all spices when compared to ethanol alone. The order of AC values of spices determined by the applied methods was as follows: ABTS test > PCL assay > CV method. The obtained results were useful for classification of the tested spices into groups with high antioxidant capacity (clove, cinnamon and allspice), middle (star anise and nutmeg) and low AC (anise, ginger, vanilla, fennel, cardamom, white pepper and coriander). In conclusion, these findings may be useful for the selection of spices for further applications in different food formulations to support their function as antioxidants.

Decrease in the Antioxidant Capacity in Beverages Containing Tea Extracts during Storage

The aim of this work was to determine antioxidant capacity of beverages containing black, white, and green tea extracts using the photochemiluminescence method, and to monitor its changes based on the storage temperature and time. Samples were stored at two different temperatures (refrigerated at 4°C and laboratory temperature 22°C), analyzed after opening of the original package, and consequently after 4 and 7 days. Results of the antioxidant capacity are expressed as the standard equivalents, that is, ascorbic acid in mmol/L. The highest mean value of the antioxidant capacity was found after opening of the original package in fruit-juice-enriched samples and totaled 9.793 mmol/L. This group revealed significant dependence (P < 0.05) not only on the storage time, but also temperature. In samples without added fruit juices containing preservatives the value was 0.428 mmol/L. This group showed significant dependence (P < 0.05) on the decrease of antioxidant capacity only when based on the storage time. Samples without fruit juices or preservatives showed significant decrease in the antioxidant capacity (P < 0.05) after 4 days of storage based on the storage time. The dependence on temperature was revealed only after 7 days of storage.

Changes in polyphenolic content and antioxidant activity after thermal treatments of grape seed extract and grape pomace

This study was undertaken to investigate the effect of heat treatment on polyphenolic content and antioxidant activity in grape pomace (GP) and grape seed extract (GSE). GP and GSE were heat treated in a furnace or autoclaved at 100 °C for 15, 30 and 60 min. Structural modifications of the polyphenols during thermal processes were determined by HPLC–MS, and the antioxidant activity was determined by ABTS, DPPH and photochemiluminescence methods. In general, furnace thermal treatment of GSE and GP did not affect the total extractable polyphenols content, tannin content, procyanidin components and the antioxidant activity. Autoclave treatment caused an extensive hydrolysis of gallocatechin (70%), catechin (61%), epicatechin (65%), procyanidin B1 (75%) and procyanidin B2 (73%) in GSE, and an increase in gallic acid (71%), gallocatechin (100%) and epicatechin gallate (129%) in GP. Autoclave treatment did not affect the antioxidant activity of GSE or GP. It can be concluded that the effect of autoclave was more severe than furnace heat treatment modifying the phenolic profile in a different manner depending on the grape seed product used. These modifications were not related with changes in antioxidant activity.

In‐vitro study on the efficacy of tannin fractions of edible nuts as antioxidants

AbstractTannin fractions were isolated from crude acetonic extracts of defatted walnut, hazelnut and almond kernels using Sephadex LH‐20 column chromatography. The obtained material was characterized by content of total phenolics and electrophoretic separations using capillary zone electrophoresis (CZE). The antioxidant activities of the tannin fractions were analyzed by several methods: DPPH and ABTS assays, photochemiluminescence (PCL) method, as well as in two lipid model systems: emulsion with β‐carotene‐linoleic acid and L‐α‐lecithin liposomes. The contents of total phenolics in the tannin fractions of walnuts, hazelnuts and almonds were 550, 329 and 83 mg catechin eq/g, respectively. The electrophoretic profiles of hazelnut and almond tannin fractions were similar, in contrast to the walnut profile. All analyzed fractions exhibited strong antioxidant properties. The antioxidant capacity of lipid‐soluble (ACL) compounds determined by PCL method was the highest for the fraction isolated from walnuts – 7.35 mmol Trolox eq/g. The DPPH radical and the ABTS radical cation were scavenged by the walnut tannin fraction with a higher efficacy than by the two other fractions. EC50 values of the DPPH method were 1.8 times higher for the hazelnut fraction and 2.3 times higher for the almond fraction when compared to the walnut tannins. In turn, the total antioxidant activity values were 8.17, 2.82 and 1.98 mmol Trolox eq/g for the walnut, hazelnut and almond fractions, respectively. On the other hand, in both lipid models applied, lower antioxidant activity of walnut tannins than of hazelnut tannins was noted. The antioxidant effect of almond tannins was weaker or similar than that of walnut tannins in the β‐carotene‐linoleic acid emulsion and the L‐α‐lecithin liposomal system, respectively.

Enzymatic hot pressurized fluids extraction of polyphenolics from Pinus taiwanensis and Pinus morrisonicola

This study was engaged in application of enzymatic hydrolysis on the hot pressurized fluid extraction (HPFE) to isolate the polyphenols from the needles of Pinus taiwanensis (PT) and Pinus morrisonicola (PM). This HPFE process was investigated using an L 18 orthogonal experimental design. Our experimental results indicate that a mixed enzyme of cellulase, hemicellulase, pectinase and protease is able to enhance cell breakage during the sample pretreatment and the HPFE process. A suitable dynamic enzymatic HPFE conditions were 1.5% wt of mixed enzymes in 70% ethanol (pH 6) at a flow rate of 10 mL/min, under pressure 689 kPa and 343 K for 180 min. The content of polyphenols obtained from the dynamic mixed enzymatic hydrolysis HPFE process is higher than that obtained from the static enzymatic hydrolysis HPFE process at 4137 kPa and 343 K for 180 min. Anti-oxidative activities of the ethyl acetate fraction from partition of the resultant of the dynamic enzymatic HPFE process determined by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, peroxide radical release inhibition, nitrite oxide radical scavenging and photochemiluminescence were highly correlated with the content of polyphenols in the extracts. The extracts of PT needles have higher chemical antioxidant activities than that obtained from PM needles . However, in terms of antioxidant abilities from water-soluble and lipid-soluble fractions determined by photochemiluminescence method, the PM needles extracts demonstrated better activity than that from the PT needles extract. In the bioassay tests, the extracts of PM and PT needles demonstrate only a little viability of normal control cells at doses of 8.59 μg/mL and 5.86 μg/mL, respectively, but exhibit 10% and 16% of growth inhibition effect on DBTRG-glioblastoma cell of the human brain.

Evaluation of the antioxidant capacity of lupin sprouts germinated in the presence of selenium

Antioxidant capacity of 5 DAS (days after seeding) lupin sprouts germinated in the presence of selenate or selenite was determined by cyclic voltammetry (CV), Folin-Ciocalteu reagent (FCR) application and photochemiluminescence (PCL) methods. The hydrophilic (80% methanol) and lipophillic (hexane/methanol) extracts of 5 DAS lupin sprouts germinated in the absence of selenium (control sprouts) showed higher antioxidant capacity than ungerminated seeds. Five DAS sprouts produced in the presence of higher concentration of selenate or selenite (6–8 mg/L) showed increased total antioxidant capacity formed by both hydrophilic and lipohillic antioxidants when evaluated by CV and FCR methods. The hydrophilic extracts from sprouts produced in the presence of low concentration of selenate (2–6 mg/L) showed a significantly higher antioxidant capacity of water-soluble compounds (PCL ACW) while no changes were noted in those germinated in the presence of the highest concentration in relation to the control sprouts. In contrast, the antioxidant capacity of lipid-soluble compounds (PCL ACL) lowered significantly in relation to the control sprouts. The similar changes in antioxidant capacity of sprouts produced in the presence of selenite were found by both PCL assays. Comparison of PCL with CV and FCR reducing capacity assays has shown that these methods yielded considerably different chemical information. Moreover, the changes in total antioxidant and total reducing capacity of sprouts germinated in the presence of either selenate or selenite provided by CV and FCR assays were higher than those obtained by photochemiluminesce measurements. It can be suggested to use 6–8 mg/L of selenite rather than selenate in order to obtain a lupin sprouts with high antioxidant capacity.

Major Phenolic Acids and Total Antioxidant Activity in Mamaki Leaves, Pipturus albidus

Three phenolic acids, (+)catechins, chlorogenic acid, and rutin, were identified and quantified in Mamaki leaves using a liquid chromatograph-mass spectrometer technique. Concentrations of (+)catechins, chlorogenic acid, and rutin varied from 1.1 to 5.0 mg/g of Mamaki leaves as determined in the extract using 0.5% acetic acid in 90% aqueous methanol. This study also quantified total antioxidant capacity using the photochemiluminescence method, which was expressed in equivalents to ascorbic acid (AA). Mamaki teas brewed for 30 min contained total antioxidant activity (TAA) between 238 and 259 mg AA/g of tea. Mamaki teas brewed for 1 h and stored at 4 h, 1 d, and 3 d at 4 degrees C had available TAA 293, 271, 172, and 163 mg AA/g of tea leaves, respectively. The concentrations of (+)catechins and rutin in Mamaki leaves are compared to other types of popular teas. Mamaki teas contained relatively low amounts of TAA compared to green teas and Lipton teas.

Fatty Acid Profiles, Tocopherol Contents, and Antioxidant Activities of Heartnut (Juglans ailanthifolia Var. cordiformis) and Persian Walnut (Juglans regia L.)

The fatty acid and tocopherol compositions of three heartnut (Juglans ailanthifolia var. cordiformis) varieties (Imshu, Campbell CW1, and Campbell CW3) were examined and compared with those of two Persian walnut (Juglans regia L.) varieties (Combe and Lake). The major fatty acids found in heartnuts and walnuts were identified by gas chromatography as linoleic (18:2n-6), alpha-linolenic (18:3n-3), oleic (18:1n-9), palmitic (16:0), and stearic acid (18:0). Polyunsaturated fatty acids were the main group of fatty acids found in both heartnut and walnut, ranging from 73.07 to 80.98%, and were significantly higher in heartnut than in Persian walnuts (P < 0.001). In addition, heartnuts had significantly higher levels of 18:2n-6 and lower levels of 18:3n-3 compared to the Persian walnuts. gamma-Tocopherol was the main tocopherol homologue present in both types of nuts, followed by delta- and alpha-tocopherol. The highest concentration of gamma-tocopherol was found in Combe Persian walnut at 267.87 mug/g, followed by Lake Persian walnut and Imshu, Campbell CW1, and CW3 heartnut at 205.45, 187.33, 161.84, and 126.46 mug/g, respectively. Tocopherols, particularly the gamma-tocopherol, were found to contribute the most to the strong total antioxidant activities of both walnut and heartnut oils using either the free radical 2,2-diphenyl-1-picrylhydrazyl assay or the photochemiluminescence method.

The use of photochemiluminescence for the measurement of the integral antioxidant capacity of baobab products

The number of methods to measure antioxidants in botanicals, foods, nutraceuticals and other dietary supplements are increased considerably in the last 10 years. However most techniques require long experimental times and high costs to determine antioxidant capacity of hydrophilic or lipophilic compound in a food mixture. By means of a photochemiluminescence method, we assessed the Integral Antioxidant Capacity (IAC) which represents the sum of the antioxidant capacity of hydrophilic and lipophilic antioxidants. In this study the IAC of extracts from Adansonia digitatata (i.e. red fiber, fruit pulp and leaves), was assessed in comparison to those deriving from other natural sources of antioxidants (i.e. orange, kiwi, apple and strawberry). When compared, IAC values for the examined product resulted as follows: Adansonia digitata red fibre ⋙ Adansonia digitata fruit pulp ≫ Adansonia digitata fresh leaves ≫ Adansonia digitata seeds ⩾ Adansonia digitata radix cuticle ⩾ orange fresh pulp ≫ strawberry fresh fruit pulp > Adansonia digitata radix > bilberry fresh pulp ⩾ kiwi fruit pulp. Results clearly indicate the interesting antioxidants properties of Adansonia digitata red fibre, in particular the IAC value of baobab red fibre was 66 time higher than that of orange pulp, with value of 1617.3 μmol/g and 24.3 μmol/g, respectively.

Polyphenolic Profiles and Antioxidant Activities of Heartnut (Juglans ailanthifolia Var. cordiformis) and Persian Walnut (Juglans regia L.)

The polyphenolic compositions of three heartnut (Juglans ailanthifolia var. cordiformis) varieties (Imshu, Campbell CW1, and Campbell CW3) were examined and compared with those of two Persian walnut (Juglans regia L.) varieties (Combe and Lake). The nuts were defatted, extracted, and separated into three different fractions, the free phenolic acid (FPA), acid-hydrolyzable phenolic acid (AHPA), and bound phenolic acid (BPA) fractions. The total phenolic contents (TPCs) in both FPA and AHPA of the Persian walnuts were significantly higher (P < 0.001) than those of the heartnuts, but not in the BPA (P = 0.20). LC-ESI-MS(n)() studies revealed that except for the FPA fraction, the major polyphenolics in both heartnut and Persian walnut were ellagic acid and valoneic acid dilactone. Persian walnuts contained an average of 0.29 and 1.31 mg of ellagic acid/g nut in the 80% methanol extractable fractions FPA and AHPA, respectively. Heartnuts contained an average of 0.16 and 0.60 mg of ellagic acid/g nut in the respective fractions. Bound ellagic acid in the residue was 0.93 and 0.70 mg/g of nut in the Persian walnut and in the heartnut, respectively. Valoneic acid dilactone was tentatively identified and quantified as milligrams of ellagic acid equivalent per gram of nut. These components were found to contribute to the strong total antioxidant activities measured using ferric reducing antioxidant power and photochemiluminescence methods.

Isoflavone characterization and antioxidant activity of ohio soybeans.

Seventeen Ohio soybeans were screened for isoflavone content and antioxidant activity. Isoflavone content was determined by C(18) reversed phase high-performance liquid chromatography coupled with a photodiode array detector. Antioxidant activities of soybean extracts were measured using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical and photochemiluminescence (PCL) methods. The highest and lowest total isoflavone contents were 11.75 and 4.20 micromol/g soy, respectively, while the average was 7.12 micromol/g soy. Antioxidant activities of soybean extracts ranged from 7.51 to 12.18 micromol butylated hydroxytoluene (BHT) equivalent/g soy using the DPPH method. Lipid and water soluble antioxidant activities of soybean extracts ranged from 2.40 to 4.44 micromol Trolox equivalent/g soy and from 174.24 to 430.86 micromol ascorbic acid equivalent/g soy, respectively, using the PCL method.