苦荞不同部位酚类化合物组成与抗氧化活性

目的:研究苦荞不同部位酚类化合物组成与抗氧化活性。方法:利用70%乙醇分别提取苦荞壳、苦荞麸皮和苦荞粉三部分中的酚类物质,并分析提取物的酚类化合物组成和抗氧化活性。结果:麸皮部位总酚、总黄酮分别为(3 042±31) mg GAE/100 g·DW和(5 290±233) mg RE/100 g·DW,分别占全苦荞的60.8%和67.7%。芦丁是麸皮提取物中的主要酚类化合物,其含量为(5 152±61) mg/100 g·DW。苦荞壳、苦荞麸皮和苦荞粉提取物均表现出抗氧化活性,其中苦荞麸皮提取物的抗氧化活性最强,其ORAC、FRAP、DPPH自由基清除率和ABTS自由基清除率分别为(1 503.3±249.5)μmol/g·DW、(8 477.5±441.1) mg TE/100 g·DW、(5 642.4±241.3) mg TE/100 g·DW和(16 764±742) mg TE/100 g·DW。结论:麸皮是苦荞酚类化合物的主要富集部位,这些化合物表现出较强的抗氧化活性。     

苦荞酒酒糟中酚类化合物成分分析及其体外抗氧化活性

目的:探究苦荞酒酒糟中酚类化合物的组成及含量,并研究其抗氧化活性。方法:通过高效液相色谱和液相质谱鉴定苦荞酒酒糟中酚类化合物的组成,并评价苦荞酒酒糟的体外抗氧化活性。结果:苦荞酒酒糟中共鉴定出7种酚类化合物,包括5种黄酮类化合物和2种酚酸类化合物,其中芦丁含量最高为(9.350±0.050) mg/g、其次为槲皮素、异槲皮素、山奈酚-3-o-芸香糖苷及山奈酚。当苦荞酒糟提取液质量浓度为0.5 mg/mL时,对羟自由基、ABTS⁺自由基、DPPH自由基的清除率分别为(73.29±0.09)%,(96.21±0.25)%,(82.55±0.68)%,FRAP值为(2.49±0.09) mmol/L。结论:发酵后的苦荞酒酒糟提取物具有一定的抗氧化活性,在低浓度条件下,对羟自由基和ABTS⁺自由基仍表现出较好的清除效果。     

基于HepG2细胞模型的褐赭色羊肚菌多酚抗氧化及抗增殖活性研究

本实验研究了褐赭色羊肚菌游离酚和结合酚体内抗氧化能力以及对HepG2细胞的毒性和抗增殖作用。采用HPLC对褐赭色羊肚菌多酚组分进行鉴定,测定多酚抗氧化能力指数(ORAC);以人肝癌细胞HepG2为模型,测定多酚细胞抗氧化活性(CAA值)及抗增殖活性(EC50值)。结果显示:褐赭色羊肚菌游离酚和结合酚含量分别为(4.27±0.07)、(0.14±0.01)mg GAE/g DW;其ORAC值分别为(4624.52±400)、(429.41±60)μmol TE/100 g DW;CAA值分别为(15.33±0.60)、(0.37±0.01)μmol QE/100 g DW(PBS清洗)和(51.84±0.83)、(1.27±0.04)μmol QE/100 g DW(不经PBS清洗)。游离酚和结合酚浓度为125μg/m L和70μg/m L时,对HepG2细胞增殖抑制率分别为77.28%、66.31%,且试验浓度范围内,羊肚菌多酚对HepG2基本无细胞毒性。褐赭色羊肚菌多酚具有一定的细胞抗氧化及抗增殖活性,可将褐赭色羊肚菌作为开发此类功能营养食品的原料,为羊肚菌的进一步综合利用提供理论依据。     

体外模拟胃肠消化过程中蒸汽爆破处理的苦荞麸皮的抗氧化及抗增殖活性

利用蒸汽爆破技术对苦荞麸皮进行预处理,并结合体外模拟胃肠消化模型,研究了汽爆处理前、后的苦荞麸皮多酚在不同胃肠消化阶段的释放量,抗氧化及抗增殖活性。结果表明:汽爆处理前后的苦荞麸皮多酚释放量及氧自由基吸收能力均有提高;汽爆处理后苦荞麸皮胃、肠消化液的细胞抗氧化性增强,EC50值分别为(19. 95±0. 37)和(150. 32±6. 43) mg/m L;汽爆处理后苦荞麸皮胃消化液对Hep G2细胞有抑制效果,EC50值为(9. 37±1. 20) mg/m L。说明蒸汽爆破处理的苦荞麸皮具有一定的抗氧化及抗增殖活性,可为科学评价苦荞麸皮的营养价值提供参考。     

亮叶杨桐叶中酚类物质的抗氧化和抗HepG2细胞增殖作用

研究春秋两个季节亮叶杨桐叶中酚类物质体外抗氧化活性及对Hep G2细胞的抗增殖作用。采用福林酚法、硼氢化钠/四氯苯醌比色法、超氧自由基吸收能力(ORAC)、超氧自由基清除能力(PSC)、细胞抗氧化法(CAA)和亚甲基蓝染色法分析游离态/结合态多酚含量、游离态/结合态黄酮含量、游离态/结合态提取物胞外抗氧化能力、游离态提取物胞内抗氧化能力和游离态提取物对Hep G2细胞的抗增殖作用。秋季亮叶杨桐叶中游离态酚、游离态黄酮含量高,分别是142.69±0.58 mg GAE/g DW和112.98±0.37 CE/g DW;游离态提取物超氧自由基吸收能力强、超氧自由基清除能力强和细胞抗氧化能力强,分别是1723.08±109.27μmol TE/g DW、24.07±1.98μM VCE/g DW和900.84±2.68μmol QE/100 g;游离态提取物对Hep G2细胞的抗增殖作用强,EC50值为4.30 mg/m L。亮叶杨桐叶富含酚类物质,特别是秋季亮叶杨桐叶是一种新型的天然抗氧化剂的原料,可进一步开发。     

杏鲍菇发酵苦荞提取物对小鼠酒精性肝、胃损伤的保护作用

目的：研究杏鲍菇发酵苦荞提取物的体外抗氧化活性及体内对酒精性肝脏、胃黏膜损伤的保护作用。方法：本实验检测杏鲍菇发酵苦荞提取物中功能成分的含量,并分析提取物的抗氧化能力;以Lieber-DeCarli酒精液体饲料建立小鼠慢性酒精性肝脏、胃黏膜损伤模型,考察发酵后的苦荞提取物在低、高剂量(1.5 g/kg B.W.、3.0 g/kg B.W.)对肝脏和胃粘膜损伤的保护作用。结果：杏鲍菇发酵苦荞提取液中含有较多的抗氧化成分,其中多酚、黄酮、三萜含量分别为11.40±0.32 mg GAE/g DW、17.19±0.30 mg RE/g DW、7.59±0.24 mg/g,黄酮类物质：芦丁和槲皮素含量分别为13.55±0.05、0.665±0.01 mg/g;杏鲍菇发酵苦荞提取液的铁离子还原抗氧化能力及其对DPPH和ABTS⁺自由基清除率分别为：16.66±0.65、33.49±1.26、15.68±1.17μmol Trolox/g DW;与模型组相比,高、低剂量组均能显著降低丙二醛(P<0.05)、天冬氨酸氨基转移酶(P<0.01)、丙氨酸氨基转移酶(P&...     

苦荞麸皮黄酮抗氧化及抗肿瘤活性

以西南地区的两种苦荞麸皮为实验材料（重庆酉阳苦荞麸皮（T1）;四川西昌苦荞麸皮（T2））,通过氧化自由基吸收能力实验（oxygen radical absorbance capacity,ORAC）测定苦荞麸皮黄酮的化学抗氧化能力,采用人肝癌细胞HepG2为细胞模型,研究苦荞麸皮黄酮的细胞抗氧化活性（cellular antioxidant activity,CAA）及对He pG2 细胞抗增殖活性。结果表明： T 1 和T 2 苦荞麸皮黄酮的ORAC值分别为（ 5 7 . 0±3 . 5 ） 、（73.6±6.3）μmol TE/g。T1和T2苦荞麸皮黄酮的细胞抗氧化值分别为（44.4±5.2）、（52.5±2.7）μmolQE/100 g（PBS清洗）;（32.9±3.2）、（30.9±2.2）μmol QE/100 g（不经PBS清洗）。在对HepG2细胞体外抗增殖活性研究实验中,通过与对照组细胞相比,发现当苦荞麸皮黄酮的质量浓度为21.9 mg/mL时,T1和T2苦荞麸皮黄酮对HepG2细胞增殖的抑制率分别约为51%和82%（P＜0.01）,二者相应的EC50值分别为（23.0±0.5）mg/mL和（13.7±0.1）mg/mL。因此,苦荞麸皮黄酮具有一定的体外细胞抗氧化和抗增殖的能力,可将苦荞麸皮作为此类功能性食品开发的原料资源。     

溶剂与提取方式对苦荞提取液抗氧化性能的影响

目的:比较不同溶剂体系和提取方式对苦荞抗氧化活性物质含量及活性的影响,寻找适宜实验室使用的高效、便捷的苦养抗氧化活性物质的提取方法.方法:以苦荞麸皮为试材,对比不同溶剂(80%丙酮、50%丙酮、80%甲醇、60%甲醇、80%乙醇和纯乙醇)和提取方式(均质、回流、超声波助提、浸泡法及振摇法)对苦荞麸皮提取物的总酚、总黄酮含量及抗氧化活性(清除ABTS·+、DPPH·能力及在β-胡萝卜素-亚油酸体系中的护色效果)的影响.结果:不同溶剂体系中,80%丙酮提取液的总酚和总黄酮含量最高,分别为(2 370.27±137.94)mgGA eq/100g DW、(3 361.28±132.95)mg RU eq/100g DW,其次依次为50%丙酮＞80%甲醇＞60%甲醇＞80%乙醇＞乙醇;80%丙酮提取物在3个抗氧化模型评价中排序较高.以80%丙酮为溶剂,对比不同提取方式研究中,总酚含量由高到低依次为回流提取＞均质提取、超声波30 min提取及浸泡提取＞超声波10 min提取与振摇提取.其中,超声波30 min提取液在3个抗氧化模型中表现出最强的抗氧化能力.提取时间顺序:浸泡15 h＞回流2 h、振摇2 h＞均质10min/次(3次)、超声波30min＞超声波10min.结论:80%丙酮是适于苦荞抗氧化物质提取的溶剂体系,同时辅助超声波30 min处理.是实验室便捷、高效的提取方法.     

亨氏马尾藻醇提取物及其不同溶剂萃取物的抗氧化活性研究

研究了亨氏马尾藻95%乙醇提取物不同溶剂级分的体外抗氧化活性。采用Folin-Ciocalteu法测定亨氏马尾藻醇提取物(总提取物)以及石油醚萃取物、乙酸乙酯萃取物、正丁醇萃取物和水萃取物五个部位的总酚含量,并通过DPPH·、ABTS~+·清除及ORAC三种方法评价五种提取物的抗氧化活性。结果表明,乙酸乙酯萃取物的总酚含量最高,为(12.71±0.02)mg GAE/g(没食子酸当量)。在不同抗氧化测定方法中,亨氏马尾藻醇提取物及其不同溶剂萃取物均表现出不同程度的抗氧化活性。其中,乙酸乙酯萃取物抗氧化活性较强,其DPPH和ABTS半数清除率分别为(0.89±0.01)mg/m L和(0.73±0.03)mg/m L,ORAC值达到(1803.78±81.37)μmol TE/g。     

蓝莓叶不同溶剂提取物抗氧化活性研究

研究蓝莓叶不同溶剂提取物中总酚和黄酮的含量以及抗氧化活性.分别用水、甲醇、乙醇、乙酸乙酯、氯仿、石油醚等不同极性溶剂提取蓝莓叶中的活性物质,采用Folin-Cioeaile法、三氯化铝显色法分别测定不同提取物中总酚和黄酮的含量;应用1,1-二苯基-2-三硝基苯肼(DPPH)自由基和2,2-联氮基双(3-乙基苯并噻唑啉-6-磺酸)二铵盐(ABTS)自由基清除体系及β-胡萝卜素-亚油酸体系评价其抗氧化活性,考察活性物质含量与抗氧化活性的关系.结果表明,蓝莓叶提取物的抗氧化活性随提取溶剂极性的减小而减小.水提取物具有较强的抗氧化活性,其清除DPPH·和ABTS+·的EC50分别为(12.78±0.10)、(6.35±0.03) μg/mL,抑制β-胡萝卜素淬灭IC50值为(25.33±0.02) μg/mL.含量测定显示水提物中总酚含量最高,为(264.67±0.29)mg/g,而甲醇提取物中黄酮含量最高,为(68.94±0.08)mg/g,相关性分析表明,不同溶剂提取物抗氧化能力差别较大,总酚和黄酮含量与抗氧化能力具有相关性,提示水可作为蓝莓叶抗氧化活性物质提取的优选溶剂,而总酚和黄酮含量可作为蓝莓叶抗氧化提取物的质量评价指标.     

Antioxidant,Antibacterial, and Antiproliferative Activities of Free and Bound Phenolics from Peel and Flesh of Fuji Apple

This study was conducted to investigate the antioxidant, antibacterial, and antiproliferative activities of flesh free (FF), flesh bound (FB), peel free (PF), and peel bound (PB) phenolics from Fuji apple. The PB, which had highest total phenolic contents (126.15 ± 2.41 mg/100 g wet weight) and lowest total carbohydrate contents (34.68 ± 2.78 mg/100 g wet weight), showed the strongest 2,2’‐azinobis‐(3‐ethylbenthiazoline‐6‐sulphonate) (ABTS) radical scavenging activity (EC₅₀ = 0.36 ± 0.02 mg/mL), 1,1‐diphenyl‐2‐picryhydrazyl (DPPH) radical scavenging activity (EC₅₀ = 0.26 ± 0.01 mg/mL), and ferric reducing antioxidant power (Ferric reducing antioxidant power; EC₅₀ = 0.19 ± 0.02 mg/mL) compared with those of FF, FB, and PF. The PB also showed the strongest antibacterial activities on Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes and it also showed the highest antiproliferative effects on Caco‐2 human colonic cancer cell (EC₅₀ = 1.44 ± 0.01 mg/mL) and Hela human cervical cell (EC₅₀ = 2.81 ± 0.01 mg/mL). Both free and bound phenolics from Fuji apple showed good antioxidant, antibacterial, and antiproliferative activities in our study, and bound phenolics had significantly higher activities compared with those of free phenolics.     

Analysis of Phenolic Composition of Noble Muscadine (Vitis rotundifolia) by HPLC‐MS and the Relationship to Its Antioxidant Capacity

Abstract: Phenolic compounds and anthocyanins in muscadines have attracted much attention due to their diverse biological activities. With bioassays of antioxidant activities in terms of total phenolic content (TPC), total anthocyanin content (TAC), total procyanidin content (TPA), oxygen radical absorbance capacity (ORAC), and ferric reducing antioxidant power (FRAP) of different parts of the Noble muscadine, the butanol (BuOH) extract of the muscadine skin showed the highest TPC (317.91 ± 1.83 mg GAE/100 g FW), which might be ascribed to its high TAC of 227.06 ± 1.29 mg/100 g fresh weight (FW). The ethyl acetate (EtOAc) extract of the muscadine seed contained the highest TPA (55.30 ± 0.63 mg CE/100 g FW). Correlation analyses demonstrated a significant linear relationship of TPC and TAC compared to their ORAC and FRAP values within the range of R² from 0.9283 to 0.9936, which suggested that phenolics and anthocyanins in the extracts contributed significantly to their antioxidant potential. Nineteen individual phenolics and 5 anthocyanins were identified by HPLC‐MS, which indicated different chemical profiles of anthocyanins and other phenolics in the muscadine extracts. Practical Application: The paper has provided rich information of bioactive phytochemical profiles in different solvent extracts and their correlation with the antioxidant activity in the muscadine that is a very special regional fruit in U.S. Its high content of phenolic compounds demonstrates that muscadine could be beneficial to human health.     

四种豆类中多酚、类黄酮含量及抗氧化活性研究

对豇豆、红小豆、绿豆和蚕豆4种豆类中游离态和结合态的多酚及类黄酮的含量进行测定,并比较了其体外抗氧化活性。数据表明,4种不同豆类的游离态多酚和结合态多酚含量范围分别为1.35～1.75 mg/g和8.63～10.11 mg/g;游离态类黄酮和结合态类黄酮含量范围分别为1.58～2.07 mg/g和3.92～5.08 mg/g;其中结合态多酚含量是游离态多酚的5倍以上,结合态类黄酮含量是游离态的2倍以上。4种豆类游离态和结合态提取物均具有良好的抗氧化活性,其中游离态提取物对DPPH自由基的清除能力明显高于结合态,而结合态对FRAP、ABTS、O2-自由基的清除能力明显高于游离态。豆类中含有丰富的酚类、类黄酮等物质,并且主要以结合态形式存在,具有较强的抗氧化活性。     

A comparative study on free and bound phenolic acid content and their antioxidant activity in bran of rice (Oryza sativa L.) cultivars of Eastern Himalayan range

In our study, seven most prevailing but unexplored indigenous rice cultivars of northeast India, situated in the Eastern Himalayan Range, were investigated for their phenolic acid profile, total phenolic content (TPC) and antioxidant capacities in free and bound phenolic extracts of their bran. HPLC studies showed the presence of ferulic, p‐coumaric, sinapic, caffeic, chlorogenic and vanillic acids, with ferulic and p‐coumaric acids being the dominant phenolic acids in the bound form. The lower EC₅₀ values of the bound extracts than the free extracts suggested the better radical scavenging activity of the bound extracts. Significant correlations were observed between TPC and phenolic acid content (HPLC‐DAD) of bound extracts, and between Trolox equivalents antioxidant capacity (TEAC) and phenolic acid content (HPLC‐DAD) of both free and bound extracts. The findings suggest that phenolic acids in the rice cultivars investigated were exclusively present in bound form and contribute significantly towards their antioxidant capacity.     

Bioaccessibility and antioxidant activity of phenolic compounds in cooked pulses

The aim of this study was to evaluate the bioaccessibility of polyphenols and antioxidant activity in cooked pulses and to study the effect of cooking on their total phenolic content (TPC) and antioxidant capacity. Cooked faba beans showed the highest TPC, followed by soybeans and lentils or peas. TPC ranged from 10.4 ± 0.2 to 52.9 ± 0.3 mg/100 g and was positively correlated with antioxidant activity. Cooking resulted in increased TPC and antioxidant activity of the methanolic extracts, caused by cell disruption and improved extraction of polyphenols. Although polyphenols were lost in the cooking water, boiled legumes had more polyphenols than those resulting cooking broths. In vitro gastrointestinal digestion resulted in increased TPC and antioxidant capacity of the extracts. Soybeans showed the highest amount of bioaccessible polyphenols. The release of phenolics from cooked legumes was mainly achieved during the intestinal phase. Literature data may underestimate the TPC and antioxidant capacity of pulses.     

Antioxidant and antiproliferative effects of methanol extracts from raw and fermented parts of mulberry plant (<Emphasis Type="Italic">Morus alba</Emphasis> L.)

Total phenolic content, phenolic acids, radical scavenging activity and antiproliferative properties of different parts of mulberry (Morus alba L.) were determined. The highest phenolic content was found in methanol extracts of mulberry root (117.7 ± 2.0), followed by leaves (71.4 ± 2.4), branches (49.0 ± 1.5) and fruit (11.2 ± 0.3) [mg ferulic acid equivalents (FAE) kg⁻¹ dry weight (DW)] (P < 0.05). The highest level of total phenolics in the fractions was in roots (166.2 ± 7.5 and 160.8 ± 7.2 mg kg⁻¹ DW for BuOH and EtOAC, respectively). Methanol extracts and their fractions dose dependently increased radical scavenging activity of mulberry branches, roots and leafs (more than 70%). Total phenolic content of the tested plant extracts was highly correlated with the radical scavenging activity. The antiproliferative effect of mulberry parts on human cell lines was different and connected to the concentrations of the investigated extracts. The fermentation of the mulberry leaves did increase their methanol extract antiproliferative effect only on human gastric carcinoma (SNU-601) cell line in concentration of 1,000 mg mL⁻¹. In conclusion, some plant parts of the Korean mulberry could be recommended as preventative and therapeutic agents, based on their antioxidant and antiproliferative properties.     

Antioxidant and antiproliferative activities of common edible nut seeds

Frequent consumption of nuts has been linked to a lowered risk of cardiovascular disease. Phytochemicals, especially phenolics, in nuts may be considered to be the major bioactive compounds for health benefits. Nine types of tree nuts and peanuts commonly available in the United States were evaluated for total phenolic and flavonoid contents, antioxidant, and antiproliferative activities. The profiles of total phenolics and flavonoids, including both soluble free and bound forms, were investigated by utilizing solvent extraction, base digestion, and solid-phase extraction methods. Walnuts had the highest total phenolic and flavonoid contents (1580.5 ± 58.0 mg/100 g, 744.8 ± 93.3 mg/100 g, respectively). Walnuts also possessed the highest total antioxidant activity (458.1 ± 14.0 μmol of vitamin C equiv/g of nut). Both soluble phenolic and flavonoid contents were positively correlated with total antioxidant activity (R² = 0.9901, p < 0.05; and R² = 0.9749, p < 0.05, respectively). The proliferation of HepG₂ and Caco-2 cells was significantly inhibited in a dose-dependent pattern after exposure to the extracts of nuts, with walnuts and pecans exhibiting the highest antiproliferative activity. These results provide new knowledge about health functions of nuts and may influence consumers toward purchasing nuts exhibiting greater potential health benefits.     

Antioxidant Properties of Free,Soluble Ester and Insoluble‐Bound Phenolic Compounds in Different Barley Varieties and Corresponding Malts

Ten different barley cultivars and their corresponding malts were used to obtain different fractions. Phenolics extracted belonged to free, soluble esters and insoluble‐bound fractions. Total phenolic content (TPC) of the free fraction, as measured according to the Folin‐Ciocalteu method, ranged from 37.7 to 167.2 mg gallic acid equiv/kg of dried material (GAE/kg_dw) for barley and between 34.1 and 72.3 mg GAE/kg_dw for malt. The bound phenolic content ranged from 210.3 to 320.5 and between 81.1 and 234.9 mg GAE/kg_dw for barley and malt, respectively. The contribution of bound phenolics to the TPC was significantly higher than that of free and esterified fractions. Catechin and ferulic acid, quantified by high performance liquid chromatography with diode array detector (HPLC‐DAD), were the most abundant phenolics in the free and bound fractions, respectively. The p‐coumaric acid content was lower in hulless genotypes, as compared to hulled genotypes, showing that it is mainly concentrated in the hull. The antioxidant activities of the phenolic fractions were investigated using the radical scavenging assay (DPPH) and ferricyanide reducing power. The bound phenolics demonstrated a significantly higher antioxidant capacity compared to the free and esterified phenolics. During the malting process, a significant decrease of the bound phenolics was observed with a corresponding increase of the esterified fraction.     

Effect of storage period on physiochemical,total phenolic content and antioxidant properties of bran enriched snacks

The objective of this investigation was to compare total phenolic content and antioxidant activities of various types of cereal brans enriched snack as affected by storage conditions. Extruded snacks were prepared by the addition of cereal brans (wheat, oat and rice) singly and in combination (w:r:o::2:1.5:1.5) to rice flour at 10, 20 and 30 % bran supplementation. The content of total phenolics in the extracts (conventional and microwave assisted extraction) was determined spectrometrically according to the Folin–Ciocalteu procedure and calculated as gallic acid equivalents. Radical scavenging capacity measured by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) methods was studied. The effect of the storage on antioxidant content and capacity showed that total phenolic content and antioxidant activities of bran enriched snacks decreased during storage at ambient temperature. However, a little increase in moisture content, water activity and free fatty acid was observed in six of month’s storage period.     

Phytochemicals and antioxidant capacities in rice brans of different color

Rice bran, a byproduct of the rice milling process, contains most of the phytochemicals. This study aimed at determining the concentrations of lipophilic, solvent-extractable (free), and cell wall-bound (bound) phytochemicals and their antioxidant capacities from brans of white, light brown, brown, purple, and red colors, and broccoli and blueberry for comparison. The concentrations of lipophilic antioxidants of vitamin E (tocopherol and tocotrienols) and γ-oryzanols were 319.67 to 443.73 and 3861.93 to 5911.12 μg/g bran dry weight (DW), respectively, and were not associated with bran color. The total phenolic, total flavonoid, and antioxidant capacities of ORAC (oxygen radical absorbance capacity), DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging, and iron-chelating in the free fraction were correlated with the intensity of bran color, while variations of these in the bound fraction were less than those in the free fraction among brans. Compounds in the bound fraction had higher antioxidant capacity of ORAC than DPPH, relative to those in the free fraction. The bound fraction of light-color brans contributed as much to its total ORAC as the free fraction. Total proanthocyanidin concentration was the highest in red rice bran, while total anthocyanin was highest in purple brans. The predominant anthocyanin was cyanidin-3-glucoside. Red and purple brans had several fold higher total phenolics and flavonoids as well as ORAC and DPPH, from both free and bound fractions, than freeze-dried blueberry and broccoli. These results indicate that rice brans are natural sources of hydrophilic and lipophilic phytochemicals for use in quality control of various food systems as well as for nutraceutical and functional food application.