Phenolic content,anthocyanins and antiradical capacity of diverse purple bran rice genotypes as compared to other bran colors

Anthocyanins are flavonoids, a subgroup of phenolic compounds in bran of purple rice that have shown health benefits in animal studies and human clinical trials. We studied the genetic diversity of the concentrations of total phenolics, flavonoids and anthocyanins, and, antiradical capacity in diverse purple rice brans. More than 13-, 12-, 25- and 8-fold variations were found for these respective traits. Cyanidin-3-glucoside and peonidin-3-glucoside were the major anthocyanins identified. The color parameter b* of whole grain rice was correlated with anthocyanins and can be used as a non-destructive quick screening tool. Purple brans that accumulated both anthocyanins and proanthocyanidins had the highest total phenolics, total flavonoids, and oxygen radical absorbance capacity among all color brans. Purple brans had the widest genotypic diversity of these chemical traits, followed by red, brown, light brown, and white. In terms of antioxidant properties of total flavonoid compounds in the sample extracts, purple and red brans had similar reducing capacity per unit of total flavonoids; while purple bran had higher oxygen radical absorbance capacity per unit of total flavonoids. In conclusion, new rice cultivars with colored bran having specific amounts and types of phenolic compounds can be developed using traditional breeding.     

Antioxidant activity of small grain cereals caused by phenolics and lipid soluble antioxidants

In this study, the content of soluble, free forms of phenolic compounds (total phenolics, flavonoids, PVPP (polyvinylpolypyrrolidone) bound phenolics, proanthocyanidins and phenolic acids), as well as the content of carotenoids and tocopherols, were determined in whole grains of bread and durum wheat, rye, hull-less barley and hull-less oat, each represented with four genotypes. Antioxidant activity was evaluated as radical scavenging activity with DPPH (2,2-diphenyl-1-picrylhydrazyl) reagent, as well as by hydrogen transfer reaction (reduction power) based on the reduction of Fe³⁺. Generally, a considerable variation in antioxidant activities and phytochemical contents was observed between the cereals. Remarkably higher DPPH radical scavenging ability and reducing power were detected in hull-less barley, followed by rye and hull-less oat and durum and bread wheat, indicating that small grain species have different major antioxidants with different properties. Hull-less barley had the highest content of total free phenols, flavonoids, PVPP bound phenolics and contained flavan-3-ols, not found in other species. Hull-less oat had the highest content of tocopherols, very high content of yellow pigments and PVPP bound phenolics. Ferulic acid was the major free phenolic acid in small grain cereals tested. The relationship between the content of soluble phenols, as well as reducing power and DPPH^• scavenging activity are also considered.     

Chemopreventive Effects of Free and Bound Phenolics Associated to Steep Waters (Nejayote) Obtained After Nixtamalization of Different Maize Types

Free and bound phenolics extracts from nejayote solids were obtained after optimally lime-cooking blue, normal white, red, normal yellow, high-carotenoid and quality protein maize types. The extraction yield ranged from 4.47 to 10.05%. Bound phenolics extracts had higher content of total phenolics, antioxidant activity and ferulic acid compared to the free phenolics extracts. In general, free phenolics extracts were less cytotoxic than the bound phenolics counterparts. Bound phenolics extracts had higher induction of quinone reductase (QR) and particularly the normal yellow nejayote exerted the highest chemopreventive index tested in Hepa1c1c7 cells. When tested for monofunctional phase 2 induction capacity in BPrc1 cells, the bound phenolics extracts of blue, normal white and quality protein nejayotes were better inducers than the normal yellow counterpart. Particularly, the free phenolics extract of the white maize nejayote induced BPrc1 cells QR and exerted a higher chemopreventive index compared to the bound phenolics extract. Therefore, the nejayote of the normal white maize was the best source of monofunctional phase 2 enzyme inducers.     

Polyphenolic Composition and Antioxidant Characteristics of Kumquat (<Emphasis Type="Italic">Fortunella margarita</Emphasis>) Peel Fractions

The polyphenolic composition of two Fortunella margarita (Nagami kumquat) specimens from Greece and Egypt was investigated employing fractionation by solvent partition and liquid chromatography-mass spectrometry. The main groups of phenolics identified in the different fractions generated were C-glycosylated flavones, O-glycosylated flavones, C-glycosylated flavanones, O-glycosylated flavanones, flavonols, chalcones, phenolic acids and derivatives thereof. The antioxidant potency of the fractions was assessed using two representative in vitro tests, including antiradical activity and hydroxyl free radical scavenging activity. It was revealed that the ethyl acetate fractions from both specimens contained the higher polyphenol content and exhibited the better antioxidant characteristics. The results indicated that F. margarita peels may be regarded as a rich source of potentially bioactive polyphenols.     

超声波和微波对柑橘杂交种果皮中酚类物质浸提及其抗氧化能力的影响

以柑橘杂交品种葡萄柚、茂谷橘橙果皮为材料,研究超声波和微波对柑橘果皮提取物中酚类物质及其抗氧化活性的影响。结果表明:葡萄柚果皮中含有丰富的柚皮苷、芦丁、橙皮素等酚类物质,茂谷橘橙果皮中含有丰富的槲皮素、川陈皮素、橙皮素等酚类物质。葡萄柚果皮提取液的抗氧化活性高于茂谷橘橙。葡萄柚果皮超声波提取液中酚类物质的含量和抗氧化活性高于微波提取液。柑橘果皮提取物中酚类物质的含量与其DPPH自由基和羟自由基清除能力呈正相关。此结果说明超声波提取法可提高葡萄柚果皮中酚类物质的提取率和提取液抗氧化能力。     

大叶蟹甲草不同萃取部位抗氧化活性研究

目的研究大叶蟹甲草不同萃取部位的抗氧化活性。方法采用ABTS、DPPH自由基及还原性反应体系,利用分光光度法测定大叶蟹甲草的总提液、乙酸乙酯层、正丁醇层和石油醚层在不同浓度下的抗氧化能力及其总酚含量。结果大叶蟹甲草的不同萃取部位对AB＇IS、DPPH自由基均具有较强的清除能力及还原能力,其结果与浓度呈良好的量效关系。其中乙酸乙酯层抗氧化能力最强,在浓度为0．62mg／mL时,对ABTS自由基的最大清除率为91．57％,对DPPH·的最大清除率为94．87％,与同浓度VC的清除率接近,且其IC50分别为0．066mg／mL、0．004mg／mL,测得乙酸乙酯层总酚含量最高,达10．45％。大叶蟹甲草具有较好的抗氧化能力,其中乙酸乙酯层抗氧化能力最显著,与总酚含量有较大的相关性,同时该结果也客观地反映了DPPH法、ABTS-＋法及还原性法测定大叶蟹甲草抗氧化活性的准确性。     

Phenolic Content and Radical Scavenging Capacity of Berries and Related Jams from Certificated Area in Serbia

Chemical composition and the effects of domestic processing and storage were studied in organically cultivated or wild growing berries, harvested in certificated area in Serbia. The total phenolics content in fresh berries ranged from 380 to 1660 mg GAE/100 g. The phenolic content decreased during the processing to jams, and storage in almost all samples, except in black currant. Among fresh berries, the highest amount of total anthocyanins was found in bilberry (0.61 ± 0.03 %). Processing and storage caused decrease in anthocyanin content. The most ubiquitous anthocyanin aglycone was found to be cyanidin. Ellagic acid was detected in fresh and frozen black raspberries and related jams, and its content increases during thermal processing to jam. Among fresh berries, bilberry showed the strongest DPPH radical scavenging activity with an IC₅₀ value of 0.82 mg/ml. However, frozen as well as processed berries in our study still showed comparable high values of radical scavenging activity. After 9 months of storage all investigated jams were microbiologicaly correct. Regardless of the losses in the amount of total phenolics, total anthocyanins and radical scavenging activity, frozen berries and related jams are still excellent sources of nutritional substances with antioxidant potential.     

Variation in Antioxidants,Bioactive Compounds and Antioxidant Capacity in Germinated and Ungerminated Grains of Ten Rice Cultivars

Present study was conducted to characterise ten rice(Oryza sativa L.) cultivars viz. IET-23466, Dhan-201, IET-23448, MAS-946, IET-23445, IET-23463, IET-23455, PR-123, PR-115 and IET-23449 based on antioxidants(total phenolics, flavonols and tannins), bioactive compounds(phytic acid, gamma amino butyric acid, tocopherol and reduced ascorbate) and antioxidant activity(1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, hydroxyl radical scavenging activity, free radical antioxidant power and total reducing power) with an aim to identify cultivars containing higher health promoting components after germination. Three cultivars IET-23466, IET-23463 and PR-123 performed better as revealed by higher level of antioxidants, bioactive compounds and antioxidant activity before and after germination. Three cultivars MAS-946, IET-23445 and IET-23449 had moderate level of antioxidants, bioactive compounds and antioxidant activity. Four cultivars Dhan-201, IET-23448, IET-23455 and PR-115 performed intermediately. Strong positive correlation was observed among total phenolics and the antioxidant activity. Phytic acid was found to be negatively correlated to the antioxidant activity. Our results highlighted that cultivars IET-23466, IET-23463 and PR-123 hold great potential after germination and would open up a useful opportunity for the functional food industry, and consumption of these cultivars after germination would afford health benefits to consumers since they contain higher level of antioxidants.     

Changes in Phenolic Compounds in Garlic (<Emphasis Type="Italic">Allium sativum</Emphasis> L.) Owing to the Cultivar and Location of Growth

The contents of total phenolic compounds, flavonoids, and phenolic acids were determined in selected garlic cultivars grown at four locations. The total phenolic content varied from 3.4 mg gallic acid equivalents (GAE)/g of dry matter (dm) to 10.8 mg GAE/g of dm with a mean value of 6.5 mg GAE/g of dm. The myricetin, quercetin, kaempferol, and apigenin flavonoids were not detected in any of the samples. Caffeic acid and ferulic acid were the major phenolic acids found with mean values of 2.9 mg/kg of dm and 2.6 mg/kg of dm, respectively. The mean contents of vanillic, p-hydroxybenzoic, and p-coumaric acids were comparable (0.4–0.8 mg/kg of dm), and the level of sinapic acid was negligible (< 0.1 mg/kg of dm). There was a significant effect of location but an insignificant effect of genotype on contents of caffeic, vanillic, p-hydroxybenzoic, and p-coumaric acids. However, genotype but not location affected the contents of total phenolics and ferulic acid. On average, the white garlic cultivars and Chinese garlic cultivars contained higher contents of total phenolics and ferulic acid than the purple garlic cultivars. However, the differences in the total phenolic content between the purple and white garlic cultivars were not significant.     

Total phenolics,flavonoids, antioxidant capacity in rice grain and their relations to grain color,size and weight

Total phenolics, flavonoid contents and antioxidant capacity from a wide collection of rice germplasm were measured, and their relations to grain color, grain size and 100-grain weight were investigated. Highly significant genotypic differences were observed in total phenolics, flavonoid contents and 2,2-azino-bis-(3-ehylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical cation antioxidant capacity. They displayed an increasing order in the white rice, red rice and black rice, yet several white rice had higher phenolics and flavonoids contents than the red rice. Significant positive pair-wise correlations were found among the phenolics, flavonoid contents and antioxidant capacity, and the coefficient between the phenolic contents and antioxidant capacity was extremely high (r = 0.96). Among all rice accessions, the grain color parameters had negative correlations with the phenolics, flavonoid contents and antioxidant capacity (p < 0.001). The negative correlation between a* and antioxidant capacity, and the positive correlation between H° and antioxidant capacity were consistent within the respective white rice and red rice groups. Flavonoid contents had positive correlation with grain length and length to width ratio, and had negative correlation with the 100-grain weight among all rice accessions. It was also found that 100-grain weight still had negative correlations with phenolics, flavonoid contents and antioxidant capacity within the white rice genotypes. These relationships may serve as indexes to indirectly select breeding lines high in the phenolics, flavonoids and antioxidant capacity. Principal component analysis including the information for phenolics, flavonoids, antioxidant capacity, grain color parameters, grain size and 100-grain weight extracted five principal components that explained 83.7% of the total variances. The results of this study may provide new opportunities for rice breeders and eventually commercial rice growers to promote the production of rice with enhanced nutritional quality.     

不同颜色色板对假眼小绿叶蝉和天敌缨小蜂及其它蜂类的引诱效应?

研究了不同颜色色板对假眼小绿叶蝉诱集效果和对天敌缨小蜂的引诱作用，结果表明黄色板诱集的小绿叶蝉数量最多为68.33头·板-1，紫色板最低5.28头·板-1，黄色板诱集数量极显著高于其他色板（F=10.50，P＜0.01），不同色板的诱集效果为黄色＞绿色＞黑色＞灰色＞红色＞蓝色＞白色＞紫色。不同色板诱集缨小蜂的数量差异极显著（F=16.82，P＜0.01），黄色板诱集缨小蜂数量最多19.00头·板-1，色板引诱缨小蜂的数量为黄色＞绿色＞蓝色＞白色＞红色＞紫色＞灰色＞黑色。黄色板对寄生蜂的引诱力最强，平均每板30.89头，不同色板诱集的缨小蜂与假眼小绿叶蝉的益害比差异不显著（F=1.20， P＞0.05）。     

胡萝卜多糖体外抗氧化活性研究

采用热水浸提法从胡萝卜中提取胡萝卜多糖,通过测定胡萝卜多糖对超氧阴离子自由基(O-2.)、羟基自由基(.OH)、DPPH自由基的清除能力以及对卵黄脂蛋白脂质过氧化的抑制作用,研究其体外抗氧化活性。结果表明,胡萝卜多糖对.OH、O-2.、DPPH自由基具有较强的清除能力,对卵黄脂蛋白脂质过氧化具有一定的抑制作用,因此胡萝卜多糖具有良好的体外抗氧化活性。     

Antiradical properties of sorghum (Sorghum bicolor L. Moench) flour extracts

Epidemiological studies support the belief that whole grains are protective against several chronic diseases. The health benefits of whole grains are attributed in part to their unique phytochemical composition. Major phytochemicals in grains include various classes of phenolic compounds, flavonoids and coumarin derivatives, etc. Phenolic compounds present in grains possess antioxidant properties that are associated with the health benefits of grains and grain products. Sorghum is one of the main staple cereal grains in hot dry tropics and ranks fifth among cereal crops in the world. Although sorghum is rich in phenolics and tannins which are proven anticancer and cardioprotective constituents, human consumption of sorghum is limited. To our knowledge, there is limited literature on the profile of antioxidant phytochemicals in the local white variety of sorghum. Hence, the objective of this study was to investigate the antioxidant property of white sorghum flour extracts in vitro and also to identify the fractions responsible for the antioxidant activity. In the present study, we analyzed the antioxidative properties of various extracts (water, 60% methanol, 60% ethanol, and 60% t-butanol) of white sorghum flour employing the 1,1-diphenyl-2-picrylhydrazyl (DPPH) model system. Phenolics, antiradical and antioxidant activities were also examined in chromatographic sub-fractions of the soxhlet methanolic extract. Our results indicated that the various extracts exhibited significant antioxidant activity that did not correlate with the phenolic content. Further, two sub-fractions eluted with methanol and acetone/methanol were found to possess strong antioxidant activity in two assay systems. Our results suggest that a diet rich in sorghum may be useful in combating diseases in which free radical production plays a key role.     

槟榔红色素的抗氧化活性

测定槟榔红色素(areca red pigment,AP)对 DPPH·和·OH的清除能力、对脂质体过氧化的抑制能力、对Fe2+的络合能力,并测定其还原能力.结果表明:槟榔色素对DPPH·、·OH的清除能力较强:对脂质体过氧化的抑制能力很强,抑制率高达79.84%;与VE、没食子酸(gallic acid,GA)、BHT相比,槟榔色素的还原力、对Fe2+的络合能力较弱.说明槟榔红色素是较好的抗氧化剂.     

Radical scavenging activity of einkorn (Triticum monococcum L. subsp. monococcum) wholemeal flour and its relationship to soluble phenolic and lipophilic antioxidant content

The present research assessed the radical scavenging activity against the synthetic 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl radical of the water-saturated 1-butanol extracts of wholemeal flour from 63 Triticum monococcum accessions, which originated from different eco-geographical areas. On average, T. monococcum had higher radical scavenging activity than T. turgidum and T. aestivum species, which served as controls (0.90, 0.64 and 0.70 mmol TE/kg DM, for T. monococcum, T. turgidum and T. aestivum, respectively). A significant correlation between radical scavenging activity and tocol content was observed, while no correlation existed with soluble phenolics and carotenoid contents.     

Effect of the mycorrhizal symbiosis time in the antioxidant activity of fungi and Pinus pinaster roots, stems and leaves

The ectomycorrhizal (ECM) symbiosis that develops between the roots of host trees and the soil ECM fungi is an important factor towards the survival, health and growth of these trees, as it stimulates their water and nutrient uptake. Ectomycorrhizal colonization can result in the deposition of phenolic compounds in peripheral cortex cells and a similar answer can be recognized as one way of plant defense against pathogenic infections. The aim of the present work was the evaluation of antioxidant potential of the ectomycorrhizal fungi, Paxillus involutus and Pisolithus arhizus, in presence and absence of the symbiont - Pinus pinaster - in response to the symbiotic association, under different contact periods (45 days and 48 h). Phenolic contents in mycelia, culture media and plant leaves, stems and roots were determined by Folin-Ciocalteu assay, and their antioxidant properties were evaluated by three in vitro assays: 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, reducing power and lipid peroxidation inhibition through β-carotene bleaching inhibition. Comparing the response of the symbionts to the host species, P. pinaster benefited most with the association, because it generally decreases the phenolics content and the antioxidant activity values in the presence of both ectomycorrhizal fungi along time. P. arhizus also decreased, in general, its phenolics levels and antioxidant properties, alongside with P. pinaster, unlike P. involutus that did not have the same response as it increases its content of phenolics and some of its values of antioxidant activity. These results can be considered as an hypothetical signal of a symbiotic differential compatibility of mycorrhizal fungi for a host.     

Soil-borne transmission of cavity spot of carrots,grown in north Lincolnshire for processing

A commercial processing crop of Amsterdam forcing carrots had a very uneven field distribution of cavity spot ranging from 0% to 59% of carrots affected when harvested. Carrots grown in the soil in pots developed similar blemishes which propamocarb drenching and gamma irradiation of the soil decreased. Drenches of dieldrin, aldicarb and tolclofos-methyl did not decrease the proportion of carrots with blemishes. It is suggested that cavity spot is soil borne, caused by an organism that may be controlled by fungicides with activity against oomycete fungi.     

Phase II-Inducing,Polyphenols Content and Antioxidant Capacity of Corn (<Emphasis Type="Italic">Zea mays</Emphasis> L.) from Phenotypes of White,Blue, Red and Purple Colors Processed into Masa and Tortillas

White, blue, red and purple corns (Zea mays L.) were lime-cooked to obtain masa for tortillas. The total phenolics and anthocyanins content, antioxidant activity expressed as total reducing power (TRP), peroxyl radical bleaching (PRAC), total antioxidant activity (TAA) and quinone reductase (QR) induction in the murine hepatoma (Hepa 1 c1c7 cell line) as a biological marker for phase II detoxification enzymes were investigated. Among the extracts prepared from raw corn varieties the highest concentration of total phenolics, anthocyanins, antioxidant index and induction of QR-inducing activity were found in the Veracruz 42 (Ver 42) genotype. The nixtamalization process (masa) reduced total phenolics, anthocyanins and antioxidant activities and the ability for QR induction when was compared to raw grain. Processing masa into tortillas also negatively affected total phenolics, anthocyanin concentration, antioxidant activities, and QR induction in the colored corn varieties. The blue variety and its corresponding masa and tortillas did not induce QR. Ver 42 genotype and their products (masa and tortilla) showed the greatest antioxidant activity and capacity to induce QR     

Evaluation of the Total Antioxidant Capacity,Polyphenol Contents and Starch Hydrolase Inhibitory Activity of Ten Edible Plants in an In vitro Model of Digestion

The total phenolics contents, total antioxidant capacity (TAC) and starch hydrolase inhibitory activity of the aqueous extracts of 10 edible plants and the stability of these parameters after the gastric and duodenal digestion in an in vitro model was investigated. The TAC was evaluated using the oxygen radical absorbance capacity (ORAC) assay, ferric reducing antioxidant power (FRAP) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH?) and 2, 2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS?+) radical scavenging assays. Characterization and quantification of five polyphenol compounds which were previously identified to be present in all the selected plants were carried out. None of the extracts showed a decrease in the total phenolics content or the ORAC and FRAP values following digestion. None of the quantified phenolic compounds had decreased during any of the digestion phases – an observation which was deemed as beneficial in terms of therapeutic properties. Overall, the parameters analyzed were relatively stable throughout the digestive process in all the extracts.

     

视频扫描测定油菜饼粕自由基清除活力方法的研究

用视频扫描平板色谱和稳定自由基1，1－二苯基－2－间三硝苯基偕腙肼（DPPH）检测油菜饼粕自由基清除活力的方法，研究抗坏血酸，维生素E，酚酸和类黄酮等17种常见酚类化合物对自由基的清除活力，发现自由基清除面积与样品量的相关系数为0．947－0．996，检测下限为40－690ng，以维生素E指数为清除活力指标，视频扫描法与常规标准比色法的测定结果具有良好的相关性，测定油菜饼粕提取液自由基清除活力发现，68－75％的化合物具有自由基清除能力，Rf值为0．41的化合物清除活力最高，占总活力的38％。