Simple method of isolation and purification of alpha-galactosides from legumes

A simple method for the isolation and purification of alpha-galactosides, raffinose family oligosaccharides (RFOs), from legumes has been developed. The method includes (i) imbibition of seeds, (ii) extraction with 50% ethanol, (iii) precipitation of RFOs, (iv) purification of RFOs on diatomaceous earth and charcoal, and (v) cation-exchange chromatography. The described method allows one to obtain high purity RFO preparations (90% for lentil and 80% for pea seeds, determined by HPLC-RI analysis) in the form of white, fine powder. Yields of alpha-galactosides isolated from 100 g of seeds of lentil and pea were 5.6 and 4.3 g, respectively.     

Effect of industrial dehydration on the soluble carbohydrates and dietary fiber fractions in legumes

The effects of soaking, cooking, and industrial dehydration treatments on soluble carbohydrates, including raffinose family oligosaccharides (RFOs), and also on total dietary fiber (TDF), insoluble dietary fiber (IDF), and soluble (SDF) dietary fiber fractions were studied in legumes (lentil and chickpea). Ciceritol and stachyose were the main alpha-galactosides for chickpea and lentil, respectively. The processing involved a drastic reduction of soluble carbohydrates of these legumes, 85% in the case of lentil and 57% in the case of chickpea. The processed legume flours presented low residual levels of alpha-galactosides, which are advisable for people with digestive problems. Processing of legumes involved changes in dietary fiber fractions. A general increase of IDF (27-36%) due to the increase of glucose and Klason lignin was observed. However, a different behavior of SDF was exhibited during thermal dehydration, this fraction increasing in the case of chickpea (32%) and decreasing in the case of lentil (27%). This is probably caused by the different structures and compositions of the cell wall networks of the legumes.     

Improved method to obtain pure alpha-galactosides from lupin seeds

Improvement of a previously described method of purification of alpha-galactosides, members of the raffinose family of oligosaccharides (RFOs), has been developed for lupins. The considerable amount of sucrose present in the RFO preparations obtained by the previous method has been removed by modifying the purification stage on diatomaceous earth and charcoal. The present method allows for the preparation of high-purity RFOs containing approximately 99.4% of RFOs in the form of a white fine powder, which provides new perspectives for the production of pure alpha-galactoside preparations for their use as prebiotics in functional foods.     

Compositional variations for alpha-galactosides in different species of leguminosae, brassicaceae, and barley: a chemotaxonomic study based on chemometrics and high-performance capillary electrophoresis

The contents of raffinose family oligosaccharides (RFO) and sucrose in Brassica, Lupinus, Pisum, and Hordeum species were investigated by chemometric principal component analysis (PCA). Hordeum samples contained sucrose and raffinose, and Brassica samples all contained sucrose, raffinose, and stachyose. In addition to these, the Pisum samples contained verbascose and the Lupinus samples also contained ajugose. High stachyose and low ajugose contents were found in Lupinus albus in contrast to Lupinus angustifolius, having low stachyose and high ajugose contents. Lupinus luteus had average stachyose and ajugose contents, whereas large amounts of verbascose were accumulated in these seeds. Lupinus mutabilis had high stachyose and low ajugose contents, similar to the composition in L. albus but showing higher raffinose content. The Brassica samples also showed compositional RFO variations within the species, and subgroup formations were discovered within the investigated Brassica napus varieties. PCA results indicated compositional variations between the investigated genera and within the various species of value as chemotaxonomic defined parameters and as tools in evaluations of authenticity/falsifications when RFO-containing plants are used as, for example, feed and food additives.     

Development of a single fluorescence-based optosensor for rapid simultaneous determination of fungicides benomyl and thiabendazole in waters and commercial formulations

A novel, sensitive, and straightforward spectrofluorimetric flow injection method is proposed in this work for the resolution of a binary mixture of two widely used fungicides (thiabendazole and benomyl). The continuous flow methodology is based on the implementation of on-line solid phase extraction (SPE), preconcentration, and separation of both analytes on a surface of C(18) silica gel beads placed just in the flow cell, with solid surface fluorescence detection. A 45- and 25-fold sensitivity enhancement was obtained for benomyl and thiabendazole, respectively (in relation to the liquid phase measurements in the absence of solid support). The separation of the pesticides was performed because of the different retention-desorption kinetics in their interaction with the solid support, in the zone where the stream impinges the solid material. No previous separation of the analytes before they reach the flow cell is needed, simplifying extraordinarily both the procedure and the manifold. Using a sample volume of 3200 microL, the system was calibrated in the range of 0.4-20 and 20-400 ng x mL(-)(1) with detection limits of 0.06 and 3.6 ng x mL(-)(1) for thiabendazole and benomyl, respectively, and RSD values (n = 10) smaller than 0.8% for both analytes. The RSD values obtained replacing the solid support in each measurement were lower than 3%, and the day-to-day reproducibility RSD value was also lower than 5%. Sampling frequencies of 10 and 18 h(-)(1) were obtained with 600 and 3200 microL of sample volume. Recovery studies carried out on natural water samples spiked with known amounts of both analytes at concentration levels in the range of 1-10 and 25-200 ng x mL(-)(1) provided mean recovery percentages ranging from 98.8 to 102% and from 98 to 103% for thiabendazole and benomyl, respectively. The proposed methodology was also applied to pesticide formulations.     

Oligosaccharide Content and Composition of Legumes and Their Reduction by Soaking,Cooking, Ultrasound,and High Hydrostatic Pressure

Oligosaccharides, including raffinose, stachyose, ciceritol, and verbascose, are commonly found in legumes and often result in flatulence in humans. Effects of soaking, soaking with ultrasound (47 MHz), soaking with high hydrostatic pressure (HHP, 621 MPa), and subsequent cooking on the oligosaccharide content of lentils, chickpeas, peas, and soybeans were investigated. Legumes were soaked for 3 or 12 hr in water, soaked for 1.5 or 3 hr with ultrasound, or soaked for 0.5 or 1 hr with HHP. Oligosaccharides of lentils and chickpeas were mainly composed of raffinose, ciceritol, and stachyose, while those of peas and soybeans were raffinose and stachyose. Verbascose was the minor oligosaccharide in lentils and peas and was absent in chickpeas and soybeans. Ciceritol was not detected in peas and soybeans. Total oligosaccharide content of raw legumes ranged from 70.7 mg/g in yellow peas to 144.9 mg/g in chickpeas. Soaking was effective for the reduction of oligosaccharides in the tested legumes. Compared with soaking for 3 hr, soaking legumes with ultrasound for 3 hr in all tested legumes or soaking legumes with HHP for 1 hr, with exception of soybeans, appeared to be more effective for the reduction of oligosaccharides. The effect of cooking on the reduction of oligosaccharide content of presoaked legumes was evident in lentils, while oligosaccharide content of chickpeas, peas, and soybeans was either unchanged or even increased by cooking after presoaking, with or without ultrasound, probably due to the leaching of other soluble components and the release of bound oligosaccharides during cooking. During soaking or cooking of legumes, raffinose leached out faster than other oligosaccharides.     

Raffinose family oligosaccharides in seeds of <Emphasis Type="Italic">Pisum</Emphasis> wild taxa,type lines for seed genes,domesticated and advanced breeding materials

The content of raffinose family oligosaccharides (RFOs) in pea seeds constrains their usage in feeding humans and animals. In our research, the content of soluble carbohydrates—particularly α-d-galactosides of sucrose (RFOs)—was analyzed. The materials were as follows: 248 accessions from the Polish Pisum Genebank including representatives of taxa (from species to convarietas), type lines for genes controlling seed characters, and breeding materials and cultivars. Accessions were divided into homogeneous groups considering content of total soluble carbohydrates, total RFOs and individual RFOs: raffinose, stachyose and verbascose. The highest content of total soluble carbohydrates and total RFOs were stated for accessions with wrinkled seeds (r and rb genes) and the lowest content for seeds of the wild species P. fulvum Sibth. et Sm. Accessions valuable for breeding (for further decreasing of anti-nutritional compounds) were found among domesticated taxa (P. sativum subsp. sativum convar. vulgare Alef. and speciosum (Dierb.) Alef.), breeding lines, and some wild taxa. Accessions with decreased content of a total RFOs and verbascose are particularly valuable. It was found that the content of total RFOs was the most highly, frequently, and positively correlated with a stachyose and verbascose content. However, in P. fulvum seeds with the lowest content of RFOs and verbascose, a high correlation between the content of total RFOs and stachyose was revealed. Contents of all oligosaccharides were substantially lower in lines with dominant alleles of main pea seed genes (R, A, and I). It can be assumed that wild, primitive peas were characterized by not-all-to-high (rather not high) content of oligosaccharides; then recessive mutations in mentioned genes resulted in an increased content of RFOs. It seems to be an interesting observation from an evolutionary point of view.     

A universal HPLC method for the determination of phenolic acids in compound herbal medicines

A universal method to separate and quantify 13 phenolic acids (gallic acid, chlorogenic acid, gentsic acid, vanillic acid, caffeic acid, syringic acid, sinapic acid, p-coumaric acid, ferulic acid, anisic acid, rosmarinic acid, salicylic acid, and cinnamic acid) in some compound herbal medicines was established by liquid chromatographic (HPLC). On an Agela XBP-C18 (5 microm, 4.6 mm x 150 mm) column, a multistep binary gradient elution program and a simplified sample pretreatment approach were used in the experiment. For all of the phenolic acids, detection limits ranged around 0.01 mg/L. Linear ranges of higher than 2 orders of magnitude were obtained with a correlation coefficient of 0.9991 to 1. Repeatability was 0.39-2.24% (relative standard deviation, RSD) for intraday, 1.17-3.96% (RSD) for interday, and 0.14-5.33% (RSD) for drug sample analysis. Recovery, tested by a standard addition method, ranged from 83.3% to 104.9% for various trace phenolic acids.     

Nutritional Enhancement of Soy Meal via Aspergillus oryzae Solid‐State Fermentation

Antinutritional factors in soy meal (SM) include trypsin inhibitor, galactooligosaccharides (GOSs), structural polysaccharides, and large‐molecular‐weight protein. These antinutritional factors limit the usage of SM for young monogastric animals. Aspergillus oryzae solid‐state fermentation was applied to eliminate these factors, and changes in physical and chemical characteristics of SM were investigated. A. oryzae–treated SM was more nutrient dependent than oxygen dependent, which was illustrated by scanning electron microscopy. After 36 h of fermentation, the concentration of GOSs (raffinose, stachyose, and verbascose) and trypsin inhibitor decreased from an initial value of 9.48 mmol/100 g to a nondetectable level. Structural polysaccharides decreased by 59% (w/w), and the degree of hydrolysis of SM protein increased from an initial value of 0.9 to 7% (w/w) through the seven‐day fermentation. Fermentation also modified nutritional factors. Protein content increased from 50.47 to 58.93% (w/w) after 36 h of fermentation. Amino acid contents were significantly enhanced. The research thoroughly studied the A. oryzae solid‐state fermentation of SM, and the resulting premium product could provide a better protein source for monogastric animals.     

Acute and chronic effects of honey and its carbohydrate constituents on calcium absorption in rats

The effects of honey and its carbohydrate constituents (glucose, fructose, and raffinose) on calcium absorption in rats were investigated in acute and chronic feeding studies. In the acute study, rats ( n = 120) were gavaged with an oral solution consisting of (a) 10 microCi (45)Ca, (b) 25 mg of calcium as calcium acetate, and (c) one of the following: 0 mg of honey (control), or 200, 500, or 800 mg of honey, a glucose-fructose mixture, 10.75 mg of raffinose, or 200 mg of raffinose. Another group received (45)Ca intraperitoneally. Femurs were collected 2 days later and analyzed for (45)Ca content. Rats given 500 and 800 mg of honey showed 25.5 and 33.6% increases in calcium absorption ( P<0.05), respectively, over the control group. Groups given the glucose-fructose mixture or 200 mg of raffinose had a significantly higher increase in calcium absorption than the control group (17.1 and 25.6%, respectively). In the chronic study, rats (n=96) were fed for 8 weeks with either 0% honey (control), 5% honey, 10% honey, or a glucose-fructose-raffinose (GFR) mixture. Femurs of GFR-fed rats had significantly lower calcium content, (45)Ca absorption, width, and BMD (at distal region) than control rats. Groups fed honey did not show the negative effects of GFR on bone, but had no advantage over the control group. No significant differences were observed in femur length, density, strength, or BMC among any treatment group compared to the control group. These results indicate that although a positive dose-response effect of honey and its carbohydrate constituents on calcium absorption was observed in the acute study, this effect disappeared upon long-term feeding in rats, implying adaptation had occurred.     

Ultrasensitive detection of genetically modified maize DNA by capillary gel electrophoresis with laser-induced fluorescence using different fluorescent intercalating dyes

In this work, four different fluorescent intercalating dyes are compared for the ultrasensitive CGE-LIF detection of DNA from transgenic maize in flours. The fluorescent intercalating dyes compared are YOPRO-1, SYBR-Green-I, Ethidium bromide (EthBr), and EnhanCE. For all the four dyes optimum concentrations are established, and efficient separations of DNA fragments ranging in size from 80 to 1000 bp are obtained. The comparative study demonstrates that SYBR-Green-I and YOPRO-1 provide better limits of detection (LODs) than EnhanCE or EthBr (i.e., LODs are, respectively, 700, 1000, 11300, and 97400 zmol, calculated for a 200-bp DNA fragment). Separations using YOPRO-1 are faster than those using SYBR-Green-I (30 min vs 47 min for the analysis of the 80-1000 bp DNA fragments). Also, separations using YOPRO-1 are more efficient than those using SYBR-Green-I (e.g., 2.4 x 10(6) plates/m vs 1.6 x 10(6) plates/m, respectively, calculated for the 200-bp fragment). Also, buffer depletion and cost per analysis are worse with SYBR-Green-I than with YOPRO-1. Therefore, YOPRO-1 was selected as the preferred intercalating dye. Using this fluorescent compound, analysis time reproducibility for the CGE-LIF separation of the DNA fragments is determined to be better than 1.7% (% RSD, n = 10) within the same day, and better than 1.9% (% RSD, n = 30) for three different days. Moreover, the fluorescence signal obtained using this dye is shown to vary linearly with the DNA concentration in the range studied, i.e., 1-500 ng/microL. It is demonstrated that by using this method 0.01% of transgenic maize can be detected in flour by direct injection of the PCR-amplified sample.     

Rapid method for quantitative analysis of the aroma impact compound, 2-acetyl-1-pyrroline, in fragrant rice using automated headspace gas chromatography

A rapid method employing static headspace gas chromatography (HS-GC) has been developed and validated for quantitative analysis of the impact aroma compound, 2-acetyl-1-pyrroline (2AP), in grains of fragrant rice. This developed method excludes wet extraction, and the rice headspace volatiles are brought directly and automatically to GC analysis. The conditions of the static HS autosampler were optimized to achieve high recovery and sensitivity. The most effective amount of rice sample used was 1 g, which provided 51% recovery and a linear multiple headspace extraction (MHE) plot of the peak area of 2AP. The sensitivity of the method was enhanced by utilizing a megabore fused silica capillary column in conjunction with a nitrogen-phosphorus detector (NPD). Method validations performed for both static HS-GC-FID and HS-GC-NPD demonstrated linear calibration ranges of 20-10 000 (r(2) = 0.9997) and 5-8000 (r(2) = 0.9998) ng of 2AP/g of rice sample, respectively. The limits of detection for both systems were 20 and 5 ng of 2AP, and the limits of quantitation were 0.30 and 0.01 g of brown rice sample, respectively. Reproducibility calculated as intraday and interday coefficients of variation were 3.25% RSD (n = 15) and 3.92% RSD (n = 35), respectively, for SHS-GC-FID and 1.87% RSD (n = 15) and 2.85% RSD (n = 35), respectively, for SHS-GC-NPD. The method was found to be effective when applied to the evaluation of aroma quality, based on 2AP concentrations, of some fragrant rice samples.     

Fermented pigeon pea (Cajanus cajan) ingredients in pasta products

Pigeon pea (Cajanus cajan var. aroíto) seeds were fermented in order to remove antinutritional factors and to obtain functional legume flour to be used as pasta ingredients. Fermentation brought about a drastic reduction of alpha-galactosides (82%), phytic acid (48%), and trypsin inhibitor activity (39%). Fermented legume flours presented a notable increase of fat and total soluble available carbohydrates, a slight decrease of protein, dietary fiber, calcium, vitamin B2, vitamin E, and total antioxidant capacity, and a decrease of soluble dietary fiber, Na, K, Mg, and Zn contents. No changes were observed in the level of starch and tannins as a consequence of fermentation. The fermented flour was used as an ingredient to make pasta products in a proportion of 5, 10, and 12%. The supplemented pasta products obtained had longer cooking times, higher cooking water absorptions, higher cooking loss, and higher protein loss in water than control pasta (100% semolina). From sensory evaluations, fortified pasta with 5 and 10% fermented pigeon pea flour had an acceptability score similar to control pasta. Pasta supplemented with 10% fermented pigeon pea flour presented higher levels of protein, fat, dietary fiber, mineral, vitamin E, and Trolox equivalent antioxidant capacity than 100% semolina pasta and similar vitamins B1 and B2 contents. Protein efficiency ratios and true protein digestibility improved (73 and 6%, respectively) after supplementation with 10% fermented pigeon pea flour; therefore, the nutritional value was enhanced.     

Investigations into genotypic variations of peanut carbohydrates

Carbohydrates are known to be important precursors in the development of roasted peanut quality. However, little is known about their genotypic variation. A better understanding of the role of carbohydrates in roasted peanut quality requires first an understanding of the genotypic variation in the soluble carbohydrate components. Ion exchange chromatography was used to isolate 20 different carbohydrate components in 52 genotypes grown in replicated trials at two locations. Inositol, glucose, fructose, sucrose, raffinose, and stachyose were quantitated, and 12 unknown peaks were evaluated on the basis of the peak height of the unknown relative to the cellobiose internal standard peak height. Peaks tentatively identified as verbascose and ajugose could not be properly integrated because of tailing. Of the 18 carbohydrates that were estimated, 9 exhibited significant variation between test environments, 5 among market types, 14 among genotypes within market types, and 11 exhibited some significant form of genotype x environment interaction. Genotypes accounted for 38-78% of the total variation for the known components, suggesting that broad-sense heritability for these components is high. The observed high genotypic variation in carbohydrate components is similar to the high genotypic variation observed for the sweetness attribute in roasted peanuts, which raises the question regarding possible interrelationships. The establishment of such interrelationships could be most beneficial to peanut breeding programs to ensure the maintenance of flavor quality in future peanut varieties.     

Pesticide sorption and diffusion in natural clay loam aggregates

Pesticide sorption in soils is controlled by time-dependent processes such as diffusion into soil aggregates and microscopic sorbent particles. This study examines the rate-controlling step for time-dependent sorption in clay loam aggregates. Aggregates (5 mm) were stabilized with alginate, and adsorption of azoxystrobin, chlorotoluron, and cyanazine was measured in batch systems equilibrated for periods between 1 h and 7 days. Stepwise desorption was measured at 1- or 3-day intervals following 1 or 7 days of adsorption. Time-dependent adsorption was also measured on dispersed soil. Results were interpreted using process-based modeling. Adsorption on dispersed soil was described by intraparticle sorption and diffusion. Adsorption in the aggregates was much less than in suspension, suggesting that part of the sorption capacity of the dispersed soil was not available within the aggregates (approximately 50%). Adsorption and desorption were reversible and could be described by pore diffusion into the aggregate with effective diffusion coefficients between 0.5 x 10(-10) and 1 x 10(-10) m2 s(-1), a factor 3-6 slower than estimated theoretically. Intraparticle diffusion did not seem to contribute to sorption in the aggregates at this time scale. Apparent hysteresis was explained by nonattainment of equilibrium during the adsorption and desorption steps.     

Antioxidant synergy and regeneration effect of quercetin, (-)-epicatechin,and (+)-catechin on alpha-tocopherol in homogeneous solutions of peroxidating methyl linoleate

Antioxidant interactions between flavonoids and alpha-tocopherol have been demonstrated by oximetry (oxygen concentration measured by ESR signal line width). In tert-butyl alcohol, a solvent in which flavonoids are weak retarders of peroxidation of methyl linoleate when initiated by alpha,alpha'-azoisobutyronitrile, quercetin and (-)-epicatechin were found to act synergistically with the chain-breaking antioxidant alpha-tocopherol. In chlorobenzene, a solvent in which flavonoids are chain-breaking antioxidants, quercetin and (+)-catechin each regenerated alpha-tocopherol, resulting in a co-antioxidant effect. The stoichiometric factor of the flavonoids as chain-breaking antioxidants in 1:1 mixtures with alpha-tocopherol was measured to be close to 1 for quercetin and slightly smaller for the catechins. The apparent inhibition rate constant, k(inh), for the mixture quercetin/alpha-tocopherol was measured to be 4.1 x 10(5) and 2.6 x 10(6) M(-1) s(-1) in tert-butyl alcohol and chlorobenzene, respectively, at 50 degrees C. A k(inh) of 4.4 x 10(5) M(-1) s(-1) was measured for (+)-catechin alone in chlorobenzene at 50 degrees C.     

Microdetermination of naphthionic acid in serum and amniotic fluid

A simple, rapid, sensitive, and reproducible microdetermination of naphthionic acid (NA) in serum and amniotic fluid is described. The detection limit of the method is 1 ng NA in 20 microL serum, and 3 ng NA in 50 microL amniotic fluid. The concentration of nonderivatized NA was measured by fluorescence spectrophotometry (excitation 328 nm, emission 420 nm) of the supernate, after precipitation of proteins with absolute ethanol and heating for 30 min at 75 degrees C. Standard deviations of determinations for 2, 10, and 50 ng NA in 20 microL serum were 10.1, 7.59, and 7.64%, respectively. An analyst can perform about 100 determinations daily; results are available within 2 hr of sampling. A modification of the procedure to permit quantitation of NA in urine is also described.     

Flax (Linum usitatissimum) seed cake: a potential source of high molecular weight arabinoxylans?

Water-soluble polysaccharides were extracted from flaxseed cake and analyzed. Two groups were separated by anion-exchange chromatography. The first one (nonretained) was the major fraction (83%) and possessed a high molecular weight (HMW) arabinoxylan (56%) with an Ara/Xyl ratio of 0.32 and an M(w) of 846 000. This polymer was accompanied by a smaller galactoglucan (44%), with an M(w) of 6.5 x 10(4). The latter group (17%), retained by the gel, was further described as a HMW pectin heterogeneous group, with, respectively, 3.1 x 10(5) and 1.3 x 10(5). Despite the presence of HMW arabinoxylans, the investigation of rheological flow sweep at the concentration of 2% (w/v) has shown a slight shear thinning behavior with a small zero-rate viscosity at 9.6 Pa.s.     

Enzymatic determination of urea in milk by sequential injection with spectrophotometric and conductometric detection

In this work, an analytical system based on the coupling of gas diffusion separation and sequential injection analysis for urea determination in milk is presented. A versatile manifold that could simultaneously be used for either spectrophotometric or conductometric detection was constructed. The sample and urease solution are sequentially aspirated into the holding coil and sent to a thermoreactor, where urea is enzymatically hydrolyzed by urease and converted into ammonium. This stream merges an alkaline solution at a confluence point where ammonia is formed. Ammonia diffuses through a hydrophobic membrane and modifies the bromothymol blue indicator color, when spectrophotometric detection is used, or changes the conductance of a boric acid solution acceptor stream, when conductometric detection is used.This methodology was applied to the determination of urea in 18 milk samples and the results were statistically comparable with those furnished by the enzymatic recommended procedure. The detection limits were 2.6 x 10(-4) and 2.8 x 10(-5) mol L(-1) for conductometric and spectrophotometric detection, respectively. Repeatability (relative standard deviation, RSD) was better than 3.7% and 2.6% for conductometric and spectrophotometric detection, respectively.     

Antioxidant mechanism of flavonoids. Solvent effect on rate constant for chain-breaking reaction of quercetin and epicatechin in autoxidation of methyl linoleate.

The rate of oxygen depletion, as measured by electron spin resonance spectroscopy (oximetry using a spin probe), in a homogeneous solution of peroxidating methyl linoleate (initiated by an azo initiator) in the presence or absence of antioxidants was converted to second-order rate constants for the inhibiting reaction of quercetin and epicatechin. In the non-hydrogen-bonding solvent chlorobenzene at 50 degrees C, k(inh) had values of 4.3 x 10(5) M(-)(1) s(-)(1) for quercetin and 4.2 x 10(5) M(-)(1) s(-)(1) for epicatechin, respectively. In the hydrogen-accepting "water-like" solvent tert-butyl alcohol, the values were 2.1 x 10(4) and 1.7 x 10(4) M(-)(1) s(-)(1), respectively. The solvent effect (factor of 20) is more significant than for alpha-tocopherol (factor of 4), and the two flavonoids have efficiencies comparable to that of alpha-tocopherol in scavenging peroxyl radicals in the nonpolar solvent but not in the hydrogen-bonding solvent.