Phenolic content and antioxidant activities of selected potato varieties and their processing by-products

The total content of free, esterified and bound phenolics of the peel and flesh of four potato varieties (Purple, Innovator, Russet and Yellow) were determined using the Folin–Ciocalteu method. The respective antioxidant activities of these potatoes and/or their skins were evaluated using several in vitro assays. The phenolic profiles of potato peel and flesh samples were determined using high-performance liquid chromatography with photodiode array detection (HPLC-DAD). Bound and esterified phenolics contributed as much or even more than the free phenolics to the antioxidant activity of the peels; extracts from Purple variety showing the highest activity. The peels of all varieties showed significantly (p < 0.05) higher phenolic content and antioxidant activities than their respective flesh. Chromatographic data showed differences in the amounts, but not in types, of phenolic compounds in the potato peel samples. Thus, potato processing discard may be used in food formulations and their extracts could potentially be employed as an effective source of antioxidants in food systems.     

不同品种蓝靛果化学成分及抗氧化活性比较

以黑龙江黑河果园产为产地的4个蓝靛果品种（1-100-82、蓝彷垂、加洛奇卡、蓝鸟）为试验材料,测定其成熟果实中的理化指标及黄酮、花色苷、多酚三种抗氧化物质的含量;以不同溶剂提取蓝靛果有效成分,测定提取物的1,1-二苯基-2-三硝基苯肼（DPPH）自由基（DPPH·）清除能力、超氧阴离子自由基（O2-·）清除能力、羟自由基（·OH）清除能力。结果表明,蓝彷垂百粒质量（135.50 g）、还原糖含量（9.51 g/100 g）高,适宜鲜食;蓝鸟多酚、黄酮含量最高（612.08 mg/g、458.20 mg/100 g）,加洛奇卡花色苷含量最高（322.64 mg/100 g）,适宜作为活性物质的提取加工品种;4种蓝靛果的醇提物抗氧化活性均优于水提物,在醇含量为60%时,抗氧化活力达到最高。     

Comparison of the antioxidant activity of two Spanish onion varieties

Phenol content and antioxidant activity of two Spanish onion varieties, namely white onion and Calçot de Valls, have been studied. White onions contained higher phenol content than Calçot onions, with values which ranged from 2.57 ± 0.51 to 6.53 ± 0.16 mg gallic acid equivalents/g dry weight (GAE/g DW) and 0.51 ± 0.22 to 2.58 ± 0.16 mg GAE/g DW, respectively, depending on the solvent used. Higher phenol content was associated with higher antioxidant capacity. White onion extracts had the highest antioxidant activity at 86.6 ± 2.97 and 29.9 ± 2.49 μmol Trolox/g DW for TEAC and FRAP assays, respectively, while the values for the Calçot variety were 17.5 ± 0.46 and 16.1 ± 0.10 μmol Trolox/g DW.     

糜子品种理化特性与体外抗氧化性研究

对39个粳性、糯性糜子品种的品质特性进行分析。结果表明,不同糜子品种的红绿值a*、粗脂肪、灰分、直链淀粉、溶解度、膨胀度、DPPH·清除率和糊化特性差异较大。糜子的平均淀粉含量73.91%,蛋白11.37%,粗脂肪4.02%,灰分0.55%,直链淀粉11.81%,支链淀粉62.10%;糜子的多酚、黄酮含量分别为8.20 mg/g、59.00 mg/100 g,对DPPH·和ABTS+·有一定的清除作用。糯性糜子较粳性糜子色泽鲜黄,具有较高的吸水性、溶解度和膨胀度。除破损值外,粳性糜子的各糊化指标值高于糯性糜子。聚类分析将糜子品种分为4类,可满足不同的加工需求。     

牡蛎活性多肽的抑菌作用与抗氧化性能研究

使用Alcalase碱性蛋白酶和菠萝蛋白酶分步酶解牡蛎蛋白,获得含牡蛎活性多肽的酶解产物,并测定了酶解产物对几种陆生致病菌和海洋病原细菌的抑菌活性和体外抗氧化能力.结果表明,牡蛎活性多肽对枯草芽孢杆菌(Bacillus subtilis)、哈维氏弧菌(Vibrio harveyi)和副溶血弧菌(Vibrio prarhaemolyticus)具有一定的抑制作用,并具有一定的还原能力和对超氧阴离子自由基的清除作用.     

Phytochemical content and antioxidant activity of six diverse varieties of whole wheat

The phytochemical content and antioxidant activity of six diverse varieties of whole wheat are reported. The free phenolic content ranged from 255 (KanQueen) to 499 (Roane) μmol gallic acid equivalents/100 g DW. The bound phenolic content ranged from 582 (Roane) to 662 (Cham1) μmol gallic acid equivalents/100 g DW. The bound fraction contributed 53.8–69.7% of the total phenolic content of the wheat varieties analysed. Ferulic acid was the predominant phenolic acid found in whole wheat. Total ferulic acid content ranged from 310.8 (Caledonia) to 496.1 (KanQueen) μmol ferulic acid/100 g DW. The percentage of ferulic acid found in the insoluble-bound fraction ranged from 87.4% (Caledonia) to 97.2% (KanQueen). Other phenolic acids, p-coumaric acid, syringic acid, vanillic acid, and caffeic acid were also detected. Lutein was the predominant carotenoid found in the whole wheat varieties analysed. Zeaxanthin, β-carotene, and β-cryptoxanthin were also detected. Mainly α- and β-tocopherols and α- and β-tocotrienols were found in all varieties of whole wheat though γ-tocopherol was detected in all but two varieties. β-Tocotrienol was the predominant form of vitamin E found in all varieties of whole wheat. The antioxidant activity was assessed using the oxygen radical absorbance capacity (ORAC) assay. The ORAC of the free fraction ranged from 1958 to 3749 μmol Trolox equivalents/100 g DW. The ORAC of the bound fraction ranged from 3190 to 5945 μmol Trolox equivalents/100 g DW. Total phenolic content was correlated with oxygen radical absorbance capacity (R² = 0.810; p < 0.001). The phytochemicals found in whole grains may be responsible for the health benefit of whole grain consumption.     

紫粒小麦麸皮花色苷提取工艺优化及其抗氧化活性研究

以紫粒小麦麸皮为原料,研究其花色苷超声波辅助提取工艺及其体外抗氧化活性。选取超声辅助提取功率、提取温度、提取时间、料液比和乙醇浓度等为考察因素进行了提取工艺的单因素及正交实验。实验结果表明,乙醇浓度为60%、料液比1∶10(g/m L)、提取时间10 min、提取温度60℃、超声波功率160 W。在此条件下,花色苷得率为(1.82±0.23)mg/g,是普通浸提法的2.09倍。体外抗氧化实验显示:紫小麦麸皮花色苷提取物具有一定的清除DPPH自由基和ABTS自由基能力以及铁还原力,其花色苷含量与DPPH自由基、ABTS自由基清除率、铁还原力有显著的相关性(相关系数R2分别为0.9938,0.9737和0.9985),IC50值分别为7.81、12.20、5.18 mg/L。这一结果将为以紫小麦麸皮花色苷为原料的功能性食品的开发提供有益提示和理论基础。      

紫粒小麦麸皮花色苷提取工艺优化及其抗氧化活性研究

以紫粒小麦麸皮为原料,研究其花色苷超声波辅助提取工艺及其体外抗氧化活性。选取超声辅助提取功率、提取温度、提取时间、料液比和乙醇浓度等为考察因素进行了提取工艺的单因素及正交实验。实验结果表明,乙醇浓度为60%、料液比1∶10(g/m L)、提取时间10 min、提取温度60℃、超声波功率160 W。在此条件下,花色苷得率为(1.82±0.23)mg/g,是普通浸提法的2.09倍。体外抗氧化实验显示:紫小麦麸皮花色苷提取物具有一定的清除DPPH自由基和ABTS自由基能力以及铁还原力,其花色苷含量与DPPH自由基、ABTS自由基清除率、铁还原力有显著的相关性(相关系数R2分别为0.9938,0.9737和0.9985),IC50值分别为7.81、12.20、5.18 mg/L。这一结果将为以紫小麦麸皮花色苷为原料的功能性食品的开发提供有益提示和理论基础。     

20种黑米的总酚含量与抗氧化活性

采用超声波辅助乙醇法提取20种黑米中的总酚,福林-酚法测定总酚含量,铁氰化钾法、铁还原抗氧化能力（FRAP）法、1,1-二苯基-2-三硝基苯肼（DPPH）法测定抗氧化活性。对黑米的总酚含量和不同抗氧化方法测定的抗氧化活性开展相关性分析。结果表明,黑米的总酚含量及抗氧化活性因品种不同存在显著差异（p<0.05）,总酚含量介于（2.305±0.035）^4.842±0.030mg/g之间,得到五种高总酚含量、高抗氧化活性黑米品种。相关性分析发现,黑米总酚抗氧化能力与总酚含量之间呈现极显著的正相关（R2>0.900,p<0.01）。本研究为全面开展黑米品种资源的选育及综合开发利用提供了参考价值和科学依据。      

Nutritional characteristics,biochemical composition and antioxidant activities of Moroccan Oat varieties

Oat has been recognized as a healthy food for a long time. In this study, physicochemical analysis including, moisture, pH, ash, fibres, proteins, starch, carbohydrates, some minerals, sugars, fatty acids, sterols, total phenolic, and flavonoid contents of four Moroccan Oat varieties (Amlal, Tissir, Zahri and Ghali) were investigated. Additionally, starch morphology has been described according to scanning electron microscopy, and viscosity as measured on a rotary rheometer, increased with stabilization time. Furthermore, Oat extracts were analyzed with regard to their antioxidant activities using DPPH radicals’ cation, Trolox equivalent antioxidant capacity and ferric reducing/antioxidant power. Results from this investigation demonstrated that Moroccan Oat varieties constitute an interesting supplement of natural antioxidants, especially phenolic compounds. Moreover, potassium was the main mineral in Oat seeds (1628.17–2541.52 mg/Kg); also, the oleic, linoleic, and palmitic acids were the dominant fatty acids. While the major sterols were, β-sitosterol, Δ-5-avenasterol and campesterol. Finally, sugar analysis by HPLC-RI indicate that sucrose content was higher than glucose and fructose respectively, and that Ghali and Amlal varieties exhibit an important total sugars levels. Those results highlight the possible contributions of Oat seeds to nutritional therapy.     

Identification of polyphenols in tobacco leaf and their antioxidant and antimicrobial activities

Crude polyphenols were extracted from tobacco leaf by 80% ethanol solution with ultrasonic treatment and then purified by a macroporous resin. The polyphenols from tobacco leaf (PTL) were subjected to analyses by reverse-phase high-performance liquid chromatography (RP-HPLC) and electrospray ionization mass spectrometry (ESI-MS). The dominant polyphenols in tobacco leaf were identified as chlorogenic acid and rutin. Furthermore, the antioxidant activities of PTL were investigated, including scavenging activities of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals (5.02 μg/ml IC₅₀ value), hydroxyl radicals (49.6 μg/ml IC50 value) and superoxide anion radicals (44.0 μg/ml IC₅₀ value), inhibition activity of lipid peroxidation (132 μg/ml IC₅₀ value) and reducing power. The proliferation inhibition activities on Escherichia coli, Staphylococcus aureus and Bacillus subtilis were also measured for evaluating the antimicrobial activity of PTL. The diameters of inhibition zones were 20.23 ± 0.42, 17.66 ± 0.86 and 12.89 ± 0.29 mm, respectively. The results showed that PTL had great potential as antioxidant and antimicrobial agent.     

Brazilian red propolis: unreported substances, antioxidant and antimicrobial activities

BACKGROUND: Chloroform, ethyl acetate and methanol extracts of a sample of red propolis from the state of Alagoas (northeast Brazil) were analyzed by gas chromatography–mass spectrometry and high‐performance liquid chromatography–diode array detection–electrospray ionization‐mass spectrometry. Antimicrobial and antioxidant activities were also obtained. RESULTS: The propolis sample contained low content of narigenin‐8‐C‐hexoside, this being the first report of a C‐glycoside in propolis. The main constituent found was characterized as 3,4,2′,3′‐tetrahydroxychalcone. Other important constituents were the chalcone isoliquiritigenin, the isoflavans (3S)‐vestitol, (3S)‐7‐O‐methylvestitol, the pterocarpan medicarpin, the phenylpropenes trans‐anethol, methyl eugenol, elimicin, methoxyeugenol and cis‐asarone, and the triterpenic alcohols lupeol and α‐ and β‐ amyrins. The methanol extract exhibited high antioxidant activities by 2,2‐diphenyl‐1‐picrylhydrazyl and β‐carotene/linoleic acid assay methods, and antimicrobial activity toward Gram‐positive and Gram‐negative bacteria. CONCLUSION: Structures are suggested for new substances never before seen in any kind of propolis. This is the first report of 3,4,2′,3′‐tetrahydroxychalcone and a flavone C‐glycoside in a propolis sample. Copyright © 2011 Society of Chemical Industry     

小麦发芽过程中酚类物质及其抗氧化活性的变化

以扶麦1228为研究对象,探讨小麦在发芽过程中酚类化合物成分和含量的变化,及其对抗氧化活性的影响。结果表明,发芽能显著提高小麦总酚含量(P0.01),且受到发芽时间的影响,发芽小麦的酚类化合物种类更加丰富,抗氧化活性更强,其中的酚类化合物主要包括咖啡酸、羟基酪醇、香草醛、对羟基苯甲酸、绿原酸、芹菜素、没食子酸、阿魏酸、芦丁、对香豆酸等。发芽能够促进小麦酚类化合物的形成,并提高其抗氧化活性,发芽小麦可作为一种潜在的天然抗氧化剂来源。     

Evaluation of antioxidant activities and total phenolic contents of typical malting barley varieties

Fourteen typical malting barley varieties from China were evaluated for their DPPH radical, ABTS radical cation and superoxide anion radical scavenging activities, reducing power, metal chelating activities, and total phenolic contents (TPC). All barley samples exhibited significant antioxidant activities determined by different assays, and contained significant levels of phenolic compounds. Gan4 and Wupi1 barley exhibited the highest DPPH radical scavenging activity, ABTS radical cation scavenging activity and reducing power. Gan4 and Humai16 barley showed the highest TPC, whereas the highest superoxide anion radical scavenging activity and metal chelating activity were found in Huaimai19 and Ken3 barley, respectively. The Pearson correlation analysis revealed that the TPC showed strong correlations with DPPH radical scavenging activity, ABTS radical cation scavenging activity, and reducing power (P < 0.01), whereas its correlations with superoxide anion radical scavenging activity and metal chelating activity were poor (P > 0.05). Moreover, DPPH radical scavenging activity, ABTS radical cation scavenging activity and reducing power were well positively correlated with each other (P < 0.01). Principal component analysis (PCA) was applied to understand the interrelationships among the measured antioxidant activity evaluation indices, and to gain an overview of the similarities and differences among the 14 barley varieties.     

Comparison of phytochemical profiles,cellular antioxidant and anti-proliferative activities in five varieties of wampee (Clausena lansium) fruits

Wampee (Clausena lansium) fruit is a seasonal food containing high levels of bioactive phytochemicals which may be useful for health benefits. This study compared the phytochemical composition, total and cellular antioxidant activities (CAA) as well as anti-proliferative activities of five different varieties of wampee fruits. The results showed that six phytochemical compounds (vanillic acid, ferulic acid, rutin, syringin, catechin and hesperetin) were found in wampee fruits. Total antioxidant activities varied dramatically in these five varieties when measured with oxygen radical absorbance capacity assay and peroxyl radical scavenging capacity assay. The results also showed that wampee fruit extracts varied enormously in their CAA and exhibited significant anti-proliferative activities against HepG2 human liver cancer cells. These results suggest the potential of wampee fruits as functional foods and industrial application of wampee fruit in the future.     

Comparison of the antioxidant activities of roasted and explosive puffed coffees

We investigated the explosive process effect on antioxidant activities of coffee bean. The total polyphenol contents of powdered extract of explosive puffing coffee bean at 0.75 MPa (PEP 7.5) and powdered extract of explosive puffing coffee bean at 0.9 MPa (PEP 9.0) were at a significantly higher than that of the powdered extract of roasting coffee bean (PER) (P < 0.05). PEP 7.5 showed the highest levels of 3‐CQA (86.23 μg mg^?1), 4‐CQA (43.71 μg mg^?1), and 5‐CQA (31.66 μg mg^?1), and PEP 9.0 had also similar levels of chlorogenic acids, with 3‐CQA (77.99 μg mg^?1), 4‐CQA (43.71 μg mg^?1), and 5‐CQA (30.32 μg mg^?1). PEP 7.5 and PEP 9.0 showed relatively higher antioxidant capacities in DPPH, ABTS, taurine, FRAP, and β‐carotene/linoleic acid assays. PEPs partly recovered the HepG2 cell damage induced by t‐BOOH. These results suggest that puffed coffee has beneficial health effects, and could be used for the development of novel processed coffee products.