Characterisation of lipoxygenase from pea seeds (Pisum sativum var. Telephone L.)

Lipoxygenase (LOX) from pea seeds (Pisum sativum var. Telephone L.) was extracted and studied of biochemical properties. The molecular mass of purified lipoxygenase was 93 kDa. The effects of substrate specificity, pH, and sensibility to various inhibitors: caffeic acid, ferulic acid, benzoic acid, catechin, quercetin and kaempferol of LOX were investigated. Lipoxygenase showed the highest activity toward linoleic acid and the lowest toward oleic acid as substrates. Kinetic studies indicated that V_max of the LOX activity was 151.5 U/min and corresponding K_m value of 0.44 × 10⁻³ M. Optimum pH of lipoxygenase was reported at 5.5. Caffeic acid was the most effective inhibitor and kaempferol was the least effective.     

Genotypic abundance of carotenoids and polyphenolics in the hull of field pea (Pisum sativum L.)

BACKGROUND: Consumption of pulse crops, including field pea, is considered effective for a healthy diet. Hulls (seed coats) play an important role for protection of the cotyledon and embryo, but also as mediating positive effects on health outcomes. The biochemical attributes of field pea hulls were thus assessed to determine the occurrence of specific phytochemicals and their genotypic variability. RESULTS: Sequestered bioproducts in mature hulls predominantly consisted of trans‐lutein and chlorophylls a and b. Trace amounts of other carotenoid and pheophytin metabolites were identified. In developing hulls, violaxanthin, neoxanthin, lutein, zeaxanthin, chlorophylls a and b and β‐carotene were detected. Genotypic differences in the accumulation of lutein and chlorophylls a and b were observed over years and locations. Polyphenolics and hydroxybenzoic acids were detected in the ‘dun’ and ‘maple’ field pea types—the only genotypes to have pigmented hulls. Unextractable patches of condensed tannin influenced the visual uniformity of the maple and dun genotypes, CDC Rocket and CDC Dundurn. CONCLUSIONS: Within the yellow and green market classes, carotenoid and chlorophyll accumulation was consistent. Green cotyledon varieties sequestered higher concentrations of lutein than the yellow cotyledon varieties. Maple and dun types were more variable, reflective of different selection criteria. The occurrence of flavonoid‐related compounds was correlated only with pigmented seed coat genotypes. The dietary potential of the chlorophylls and carotenoids that accumulated in the hulls split from the green and yellow field pea types is discussed as a value‐added prospect in food supplements. © 2012 Society of Chemical Industry     

Seed coat has no value in protecting cowpea seed against attack by Callosobruchus maculatus (F.)

Experiments were conducted to compare the oviposition preference of the cowpea seed beetle Callosobruchus maculatus (F.) on 22 cowpea varieties, with and without seed coat. The cowpeas included five resistant, four moderately resistant and 13 susceptible varieties. Ten of the varieties had smooth seed coats while 12 were wrinkled. Mean numbers of eggs laid on smooth and wrinkled varieties were not significantly different. The survival of the bruchid was also assessed on intact and decorticated seeds of five varieties, comprising two resistant varieties “Kanannado” and “IT89KD-288”, a moderately resistant variety “IT93K-513-2” and two susceptible varieties “IT87K-941-1” and “IT89KD-374-57”. There was no correlation of resistance level with the number of eggs oviposited on cowpea varieties. Under limited and free-choice conditions, cowpea seeds with intact seed coats were preferred to decorticated seeds for oviposition. Adult emergence, mean development periods and pre-adult mortality were similar when seed coats were removed or left intact. It is concluded that the seed coat may not be a useful aspect to consider for breeding of bruchid resistance into cowpea varieties.     

Isolation and characterization of a lectin with antifungal activity from Egyptian Pisum sativum seeds

A plant lectin isolated in its pure state from the Egyptian seeds of Pisum sativum (PSL) produced two bands in SDS–PAGE (5.53 and 19.3 kDa; i.e. α and β chain) but one peak by gel filtration chromatography on Sephadex G-100, corresponding to 50 kDa, i.e., a dimeric structure of two monomers, each consisting of one α and one β subunit. PSL is a glycoprotein bound with glucose (2 mol/mol of protein) and stabilized by 2 atoms of each of Ca²⁺ and Mn²⁺ per molecule of protein. It highly agglutinated human, rabbit and rat erythrocytes but weakly agglutinated chicken erythrocytes, while no agglutination occurred with sheep erythrocytes. Hemagglutination was markedly affected by acidic pH, but was heat stable below 60 °C for 30 min. Among the various tested sugars, PSL agglutination was most inhibited by mannose. PSL is rich in hydroxyl amino acids while totally lacking sulfur amino acids. PSL inhibited the growth of Aspergillus flavus, Trichoderma viride and Fusarium oxysporum.     

Antioxidant and antimicrobial activities of Laetiporus sulphureus (Bull.) Murrill

Antioxidant capacity and antimicrobial activities of Laetiporus sulphureus (Bull.) Murrill. extracts obtained with ethanol were investigated in this study. The study was aimed at determining the antioxidant activity (DPPH free radical-scavenging, β-carotene/linoleic acid systems), total phenolic content and total flavonoid concentration of L. sulphureus. Inhibition values both of L. sulphureus ethanol and the standards increased parallel with the elevation of concentration in the linoleic acid system. Inhibition values of L. sulphureus (LS) extract, BHA and α-tocopherol standards were found to be 82.2%, 96.4% and 98.6%, respectively, at a concentration of 160 μg/ml. DPPH free radical-scavenging activity was found to exhibit 14%, 26%, 55% and 86% inhibition, respectively, at concentrations of 100, 200, 400 and 800 μg/ml. Total flavanoids were 14.2 ± 0.12 μg mg⁻¹ (quercetin equivalent) while the phenolics were 63.8 ± 0.25 μg mg⁻¹ (pyrocatechol equivalent) in the extract. Positive correlations were found between total phenolic content in the mushroom extracts and their antioxidant activities. Edible mushrooms may have potential as natural antioxidants. L. sulphureus showed narrow antibacterial activity against Gram-negative bacteria and strongly inhibited the growth of the Gram-positive bacteria tested. The crude extract exhibited high anticandidal activity on Candida albicans. Therefore, the extracts could be suitable as antimicrobial and antioxidative agents in the food industry.     

Antioxidant potentials and rosmarinic acid levels of the methanolic extracts of Salvia verticillata (L.) subsp. verticillata and S. verticillata (L.) subsp. amasiaca (Freyn & Bornm.) Bornm

This study was designed to examine the in vitro antioxidant activities and rosmarinic acid levels of the methanol extracts of Salvia verticillata subsp. verticillata and S. verticillata subsp. amasiaca. The extracts were screened for their possible antioxidant activity by two complementary test systems, namely DPPH free radical-scavenging and β-carotene/linoleic acid systems. In the first case, S. verticillata subsp. verticillata was superior to the subsp. amasiaca with an IC₅₀ value of 14.5 ± 1.21 μg mg⁻¹. In the β-carotene/linoleic acid test system, inhibition capacity of S. verticillata subsp. verticillata was 74.4 ± 1.29%. Antioxidant activities of BHT, ascorbic acid, curcumin and α-tocopherol were determined in parallel experiments. Activity of rosmarinic acid was also screened for better establishing the relationship between rosmarinic acid level and antioxidant activity for the plant extracts. S. verticillata subsp. verticillata had the highest rosmarinic acid level with a value of 28.7 ± 0.89 μg mg⁻¹. There is a strong correlation between the rosmarinic acid level and antioxidant activity potential. Our results showed that rosmarinic acid and its derivatives are more likely to be responsible for most of the observed antioxidant activities of Salvia species.     

Antioxidant and antibacterial activities of exopolysaccharides from Bifidobacterium bifidum WBIN03 and Lactobacillus plantarum R315

The objective of this study was to investigate the antioxidant and antibacterial activities of exopolysaccharide (EPS) from Bifidobacterium bifidum WBIN03 (B-EPS) and Lactobacillus plantarum R315 (L-EPS). The 1,1-diphenyl-2-picrylhydrazyl (DPPH)-radical scavenging, hydroxyl radical-scavenging, and superoxide radical-scavenging abilities were measured to evaluate antioxidant activity. Inhibition of erythrocyte hemolysis and lipid peroxidation was also measured. Both B-EPS and L-EPS had strong scavenging ability against DPPH and superoxide radicals at high concentration. The inhibitory effect of B-EPS on erythrocyte hemolysis was stronger than that of L-EPS in a concentration range from 0.30 to 1.00 mg/mL, whereas the hydroxyl scavenging ability of L-EPS (39.15 ± 0.58%) was significantly higher than that of 0.15 mg/mL ascorbic acid (24.33 ± 1.17%) and B-EPS (17.89 ± 3.30%) at 0.10 mg/mL. The inhibition of lipid peroxidation of 0.50 mg/mL B-EPS and L-EPS was 13.48 ± 1.74% and 12.43 ± 0.51%, respectively, values lower than that of ascorbic acid at the same concentration (23.20 ± 1.41%). Furthermore, all these abilities were enhanced in a concentration-dependent manner. Agar diffusion assay showed that both EPS exhibited antibacterial activities against tested pathogens such as Cronobacter sakazakii, Escherichia coli, Listeria monocytogenes, Staphyloccocus aureus, Candida albicans, Bacillus cereus, Salmonella typhimurium, and Shigella sonnei at 300 μg/mL. In conclusion, both EPS have antimicrobial and antioxidant activities and could have applications in the food industry.     

Antioxidant activities of Sechium edule (Jacq.) Swartz extracts

The antioxidant activities (AA) of Sechium edule extracts were tested by three established in vitro methods, namely reducing power, β-carotene linoleate model and 1,1- diphenyl-2 picrylhydrazyl (DPPH) radical-scavenging. Leaf ethanolic extracts and leaf and seed water extracts showed strong inhibitory activity by β-carotene bleaching (AA values of 90%). Furthermore, these extracts exerted hydrogen-donating ability in the presence of DDPH stable radical (IC₅₀ 2 μg/ml). These extracts also showed strong reducing power by the potassium ferricyanide reduction method. Leaf and seed extracts may be exploited as biopreservatives in food applications as well as for health supplements or functional food, to aleviate oxidative stress.     

干燥温度对醇提余甘子多酚含量及其抗氧化活性的影响

为探究干燥方式(冷冻真空干燥、热风干燥)和干燥温度(冻干、40、60、80、100℃)对余甘子多酚活性成分的影响,利用高效液相色谱(HPLC)检测不同干燥处理后余甘子醇提液中没食子酸、柯里拉京、鞣花酸、诃子鞣酸的含量,并测定其总多酚含量和抗氧化活性(ABTS⁺自由基清除能力和DPPH自由基清除能力)。结果表明,随着干燥温度的升高,余甘子中没食子酸、柯里拉京、鞣花酸、诃子鞣酸含量均增加,100℃热风干燥时达最高(分别为12.83、6.04、16.89、13.48 mg/g)。总多酚含量与抗氧化活性(ABTS⁺·清除能力和DPPH·清除能力)也随干燥温度升高而增加,80℃热风干燥时达最高(分别为200.92、695.76、725.05 mg/g)。此外,试验结果表明柯里拉京、诃子鞣酸和总多酚的含量与余甘子醇提样品ABTS⁺自由基清除能力呈显著或极显著正相关(P<0.05或P<0.01)。本次试验中,与热风干燥相比,冷冻干燥的样品中4种多酚单体和总多酚含量以及抗氧化活性无明显优势,综合考虑,80℃热风干燥为余甘子的最佳干燥方式。     

Antioxidant Activity of Nontocopherol Hazelnut (Corylus spp.) Phenolics

Hazelnuts were investigated for the presence of antioxidant compounds other than tocopherol. Hazelnuts from 2 regions were extracted with methanol:water (2:1; v/v). Extracts were subjected to either acid or alkaline hydrolysis but neither improved the separation quality during high pressure liquid chromatography (HPLC) analysis. Nonhydrolyzed extracts of hazelnut had greater antioxidant activity in comparison to hydrolyzed extracts. The 1st 10 minute eluent in the HPLC had greater antioxidant activity relative to the later eluting fractions. Gallic acid, p-hydroxyl benzoic acid, caffeic acid and/or epicatechin, sinapic acid, and quercetin were tentatively identified using HPLC.     

Chemical and antioxidative assessment of dietary turnip (Brassica rapa var. rapa L.)

The phenolic compounds and organic acids of turnip (Brassica rapa var. rapa L.) edible parts (leaves and stems, flower buds and roots) were determined by HPLC–DAD and HPLC–UV, respectively. The results revealed a profile composed of 14 phenolics (3-p-coumaroylquinic, caffeic, ferulic and sinapic acids, kaempferol 3-O-sophoroside-7-O-glucoside, kaempferol 3-O-sophoroside-7-O-sophoroside, kaempferol 3-O-(feruloyl/caffeoyl)-sophoroside-7-O-glucoside, kaempferol 3,7-O-diglucoside, isorhamnetin 3,7-O-diglucoside, kaempferol 3-O-sophoroside, 1,2-disinapoylgentiobiose, 1,2′-disinapoyl-2-feruloylgentiobiose, kaempferol 3-O-glucoside and isorhamnetin 3-O-glucoside) and six organic acids (aconitic, citric, ketoglutaric, malic, shikimic and fumaric acids). The quantification of the identified compounds showed kaempferol 3-O-sophoroside-7-O-glucoside, kaempferol 3-O-(feruloyl/caffeoyl)-sophoroside-7-O-glucoside, isorhamnetin 3,7-O-diglucoside and isorhamnetin 3-O-glucoside as the main phenolics, and malic acid as the organic acid present in highest amounts. A screening of the antioxidative potential was also performed by means of the DPPH radical scavenging assay. Turnip flower buds exhibited the strongest antioxidant capacity.     

Phytochemicals and antioxidant activity of different parts of bambangan (Mangifera pajang) and tarap (Artocarpus odoratissimus)

Mangifera pajang (family: Anacardiaceae; local name: bambangan) and Artocarpus odoratissimus (familiy: Moraceae; local name: tarap) are popular edible fruits in Sabah, Malaysia. The flesh, kernel and peel from M. pajang; seed and flesh from A. odoratissimus were analysed for total antioxidant activity, total polyphenol, total flavonoid and total anthocyanins contents. M. pajang kernel extract displayed the highest free radical scavenging and ferric reducing activities. Total phenolic content of the samples were in the range of 5.96–103.3 mg gallic acid equivalent/g. M. pajang kernel and M. pajang flesh contained the highest and lowest total flavonoid content with the values of 10.98 and 0.07 mg rutin equivalent/g, respectively. The antioxidant activities of extracts were significantly correlated with the total phenolic and flavonoid content (but not the anthocyanins content). The phytochemicals and antioxidant properties of M. pajang and A. odoratissimus, especially their by-products (kernel/seed), indicate that they may impart health benefits when consumed and should be regarded as a valuable source of antioxidant-rich nutraceuticals.     

The in vitro and in vivo antioxidant properties of seabuckthorn (Hippophae rhamnoides L.) seed oil

The antioxidant capacity of seabuckthorn (Hippophae rhamnoides L.) seed oil was investigated with a number of established in vitro assays and in an in vivo study of carbon tetrachloride (CCl₄)-induced oxidative stress in mice. The results showed that DPPH radical scavenging activity, ferrous ion chelating activity, reducing power and inhibition of lipid peroxidation activity all increased with increasing concentrations of seabuckthorn seed oil. Moreover, the EC₅₀ values of seabuckthorn seed oil from the hydrogen peroxide, superoxide radical, hydroxyl radical scavenging assays were 2.63, 2.16 and 0.77 mg/ml, respectively. In the in vivo study, seabuckthorn seed oil inhibited the toxicity of CCl₄, as seen from the significantly increased activities of the antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase. The GSH content in the liver was also increased, whereas hepatic malondialdehyde was reduced. Taken together, these results clearly indicate that seabuckthorn seed oil has significant potential as a natural antioxidant agent.     

Antioxidant activity and total phenolic content of Agaricus brasiliensis (Agaricus blazei Murril) in two stages of maturity

The antioxidant capability and total phenolic contents of methanolic extracts of Agaricusbrasiliensis in two stages of maturity, young (YB) and mature (MB), were evaluated in this work. Four complementary assays, reducing power, radical scavenging capacity, inhibition of lipid peroxidation and chelating ability for ferrous ions were used to screen the antioxidant properties of extracts. Minor differences in the composition of phenolic compounds were detected, but the extracts showed similar antioxidant activities, except for the chelating ability for ferrous ions, higher in MB than in YB. Our results support the use of both young and mature fruiting bodies of Agaricus blazei as sources of antioxidant compounds.     

烘焙对红松种籽衣活性成分含量及抗氧化活性的影响

红松种籽衣中含有多酚、黄酮等活性成分,松籽加工中烘焙工艺会影响籽衣中活性成分含量及抗氧化活性。本研究分别对带壳松籽和不带壳松籽进行烘焙,在130℃条件下烘焙10、20、30、40min,分析其种籽衣中总多酚、黄酮含量和颜色变化,并对其抗氧化能力进行评价。结果表明:烘焙后总多酚、总黄酮含量均低于未焙烤组。不带壳烘焙种籽衣的抗氧化能力强于带壳样品。种籽衣的DPPH·清除能力在不带壳烘焙20 min时最强,IC_(50)为0.16 mg/mL,低于未烘焙组0.17 mg/mL;种籽衣的羟基自由基清除能力在不带壳烘焙20 min时最强,IC_(50)为0.10 mg/mL,低于未烘焙组0.14 mg/mL。L*值、a值、b值随着烘焙时间均呈降低趋势。总多酚和总黄酮含量与DPPH·清除能力和羟基自由基清除能力正相关,相关系数分别为0.799和0.648。种籽衣提取物最大吸收波长在274～279 nm之间。烘焙加工影响红松松籽衣中活性成分含量、抗氧化活性和颜色。     

Antioxidant activity and phenolic composition of sumac (Rhus coriaria L.) extracts

Antioxidant activity and phenolic compounds of sumac extracts were investigated. Sumac was extracted in methanol and subjected to solvent–solvent partitioning to yield two fractions as ethyl acetate and aqueous. Methanol extract was further fractioned over Sephadex LH-20 column. Antioxidant activity of extracts and fractions were screened using ferric thiocyanate and DPPH radical scavenging methods. Phenolic composition of active fraction(s) was determined by HPLC–MS systems. Those fractions which exhibited strong antioxidant activity were rich in anthocyanins and hydrolysable tannins. While gallic acid was the main phenolic acid in the extracts, anthocyanin fraction contained cyanidin, peonidin, pelargonidin, petunidin, and delphinidin glucosides and coumarates. Pentagalloyl glucose was abundant in the hydrolysable tannin fraction. Effective scavenging concentration (EC₅₀) on DPPH radical was 0.70 μg/mL both in ethyl acetate and tannin fractions, and 5.33 μg/mL in anthocyanin rich fraction. Same extracts and fractions showed moderate lipid peroxidation inhibition effect compared with the synthetic antioxidants. The findings demonstrate that sumac can be used as a natural antioxidant.     

Flavonoids of Zizyphus jujuba L. and Zizyphus spina-christi (L.) Willd (Rhamnaceae) fruits

The ripe edible fruits of jujube, Zizyphus jujuba Miller (syn. Z. sativa Gaertner, Z. vulgaris Lam.) and Christ’s thorn jujube Zizyphus spina-christi (L.) Willd (Rhamnaceae family) were phytochemically investigated, comparing their quali-quantitative flavonoids profile. Twelve compounds from both methanol extracts have been recognized as quercetin, kaempferol, and phloretin derivatives by means of HPLC/ESI-MS analyses. Six major compounds have been purified by Sephadex LH-20 column chromatography followed by HPLC and were characterized using NMR spectroscopy. One C-glycoside, 3′,5′-di-C-β-d-glucosylphloretin, was detected in Z. spina-christi. The quantitative analysis of all compounds was also reported showing a higher content of flavonoids in Z. jujuba.