Phenolic Compounds and Antioxidant Capacities of 10 Common Edible Flowers from China

The free and bound phenolic compounds in 10 common Chinese edible flowers were investigated using reversed phase high‐performance liquid chromatography. Their antioxidant capacities were evaluated using 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical‐scavenging activity, 2,2'‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulphonic acid) (ABTS) radical‐scavenging activity, oxygen radical absorption capacity (ORAC), ferric reducing antioxidant power (FRAP), and cellular antioxidant activity (CAA). Free factions were more prominent in phenolic content and antioxidant capacity than bound fractions. Paeonia suffruticosa and Flos lonicerae showed the highest total phenolic content (TPC) 235.5 mg chlorogenic acid equivalents/g of dry weight and total flavonoid content 89.38 mg rutin equivalents/g of dry weight. The major phenolic compounds identified were gallic acid, chlorogenic acid, and rutin. P. suffruticosa had the highest antioxidant capacity in the DPPH, ABTS, and ORAC assays, which were 1028, 2065, 990 μmol Trolox equivalents/g of dry weight, respectively, whereas Rosa chinensis had the highest FRAP value (2645 μmol Fe²⁺ equivalents /g of dry weight). The P. suffruticosa soluble phenolics had the highest CAA, with the median effective dose (EC₅₀) 26.7 and 153 μmol quercetin equivalents/100 g of dry weight in the phosphate buffered saline (PBS) and no PBS wash protocol, respectively. TPC was strongly correlated with antioxidant capacity (R = 0.8443 to 0.9978, P < 0.01), which indicated that phenolics were the major contributors to the antioxidant activity of the selected edible flowers.     

Antioxidant activity of three edible seaweeds from two areas in South East Asia

Total phenolic content (TPC) and antioxidant activity (AOA) of 50% aqueous methanol extracts of the marine algae, Padina antillarum, Caulerpa racemosa and Kappaphycus alvarezzi were studied. TPC was measured using Folin-Ciocalteu method while 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, ferric reducing antioxidant power (FRAP), ferrous ion chelating (FIC) assay and beta carotene bleaching (BCB) assay were used to study their AOA. P. antillarum was found to have the highest TPC, 2430±208 mg gallic acid equivalents (GAE) per 100 g dried sample and ascorbic acid equivalent antioxidant capacity (AEAC), 1140±85 mg AA/100 g. C. racemosa and K. alvarezzi displayed lower TPC and AEAC. C. racemosa had 144±22 mg GAE/100 g dried sample of TPC and 14.3±2.0 mg AA/100 g of AEAC, while K. alvarezzi had 115±35 mg/100 g dried sample of TPC and 37.8±16.8 mg AA/100 g of AEAC. In addition, P. antillarum displayed the highest reducing power, 15.7±2.6 mg GAE/g and highest chelating ability. C. racemosa and K. alvarezzi exhibited lower reducing power, 0.737±0.423 mg GAE/g and 0.561±0.269 mg GAE/g, and lower chelating ability. However, the AOA of these three seaweeds as assessed by BCB assay were equally high.     

海藻中碘的形态及其食用安全性研究进展

碘是人体甲状腺激素合成的必需元素,也是人体必需的微量元素之一。依据世界卫生组织提出的食盐加碘补碘策略, 1994年我国颁布了《食盐加碘消除碘缺乏危害管理条例》。但长期过量摄入无机碘,不仅会引起甲状腺功能失调,增加患甲状腺癌的几率,还会导致其他组织器官病变。海藻是天然的食用碘资源,有机碘含量最高达80%。通过海藻碘、有机碘和无机碘的毒性研究发现,长期大量摄入海藻碘和有机碘对甲状腺的危害要小很多。本文分析了我国补碘现状及国内外碘的限量,对比海藻碘、有机碘和无机碘的毒性差异,阐述当前海藻碘的毒性研究进展,为进一步开展海藻碘的食用安全性评估和制定碘的限量提供参考。     

Antioxidant activity and phenolic content of pressurised liquid and solid–liquid extracts from four Irish origin macroalgae

The efficiency of solid–liquid extraction (SLE) and pressurised liquid extraction (PLE) for the recovery of antioxidant and polyphenols from the Irish macroalgae, Fucus serratus, Laminaria digitata, Gracilaria gracilis and Codium fragile, was assessed using the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays and the Folin–Ciocalteu total phenol content (TPC) assay. Fucus serratus had TPC and antioxidant activities thirty times higher than the other species. Solid–liquid extraction cold water (CW_SLE) had the highest TPC (81.17 μg GAE mg^?1 sample) derived from F. serratus, compared with the TPC of 61.12 μg GAE mg^?1 sample for the corresponding PLE extract. For both SLE and PLE extracts, low TPC levels were observed in L. digitata, G. gracilis and C. fragile. The majority of SLE extracts possessed higher FRAP and DPPH activities compared with their PLE counterparts. This study indicates that the high temperatures and pressures in PLE did not enhance the antioxidant activities relative to conventional SLE extraction.     

常见药食植物提取物体外抗氧化活性的评价

本实验选用普鲁士兰法、邻二氮菲-Fe2+氧化法、光照核黄素一氮蓝四唑(NBT)法和DPPH·(1,1-Diphenyl一2-Picryl-Hydrazyl)法四种常用的体外抗氧化活性评价方法,以蒸馏水、80%乙醇和乙酸乙酯作为样品提取剂,对27种常见的植物原料的抗氧化能力进行全面的比较分析.结果表明,不同植物体外抗氧化能力差别较大,同种植物对不同抗氧化能力也存在一定差异,而同一植物的三种提取物在同一个抗氧化评价指标上也有差距.     

分段提取香茅草精油及其对食用油脂的抗氧化活性研究

目的:提取云南产香茅草精油,研究不同提馏段精油对食用油脂的抗氧化活性。方法:采用水蒸气蒸馏法分段提取香茅精油,并以猪油和菜籽油为介质,过氧化值（POV）为指标,考察香茅精油的抗氧化活性,以BHT和BHA做对照。结果:水蒸气蒸馏法提取香茅精油的最佳工艺为:料液比为1∶20,Na Cl的质量浓度为7g/L,提取时间为160min,总出油率为1.23%。GC-MS分析前20min和20¹60min香茅精油中柠檬醛、橙花醛、橙花醇等主要成分的含量差别较大。香茅精油对猪油的抗氧化活性较低。20¹60min香茅精油对菜籽油有较好的抗氧化活性,与VC复合使用时,其对菜籽油的抗氧化活性与BHT相当。20¹60min精油对DPPH·的清除能力较BHT和BHA差,而其总抗氧化活性与BHT和BHA相当。结论:香茅草精油具有较好的抗氧化活性,并且精油中高沸点物质的活性大于低沸点物质的活性。      

Antioxidant activity and free radical-scavenging capacity of a selection of wild-growing Colombian plants

BACKGROUND: The replacement of some synthetic food antioxidants by safe natural antioxidants has fostered research on the screening of raw materials to find new vegetable sources of antioxidants. In this study the antioxidant activity of eight wild‐growing Colombian plants was assessed by four complementary assays. RESULTS: An evaluation of the antioxidant activity of ten ethanolic extracts from Baccharis chilco, Cinnamomum triplinerve, Ilex laurina, Lachemilla orbiculata, Lepechinia conferta, Quercus humboldtii, Rubus urticifolius and Tephrosia cinerea was carried out. Furthermore, the total phenolic content was determined by the Folin–Ciocalteu method, and the relationship between phenolic content and activity was also statistically investigated. Cinnamomum triplinerve, L. conferta and I. laurina were found to have the highest phenolic contents. Baccharis chilco, C. triplinerve, I. laurina, L. conferta, Q. humboldtii and R. urticifolius showed higher radical‐scavenging activity (DPPH and superoxide assays) than commercial rosemary oleoresin (reference). Lachemilla orbiculata and R. urticifolius showed higher antioxidant activity (β‐carotene‐bleaching test) than the reference. The protection factor of all studied plant extracts was below that of the reference according to the Rancimat test. CONCLUSION: On the basis of the results obtained, C. triplinerve, Q. humboldtii and R. urticifolius seem to be the most promising species for further investigation in order to identify the compounds responsible for their activity. Copyright © 2011 Society of Chemical Industry     

Wild Mediterranean plants as traditional food: a valuable source of antioxidants

Some wild Mediterranean plants used as traditional food are an extraordinary source of antioxidants. We tested some properties of 10 of these herbaceous plants, used in Liguria (Northwest Italy) to prepare a traditional dish known as "prebuggiun." A total of 9 of them were found to have a polyphenol content and antioxidant properties similar or better than those of red chicory and blueberry, which are, in the case of vegetables and fruits, among the richest of antioxidants. Practical Application: In this article, we reported a study on wild plants growing in the Mediterranean area. These herbs have been neglected and this study aimed to revalue these plants because they are an extraordinary source of antioxidants. The increasing demand for natural antioxidants (additives in the food industry too) justifies the search for new sources of natural antioxidants. The revaluation of these plants will be interesting for: (1) consumer health, rediscovering a vegetable source of high antioxidant power; (2) possibility of producing new commercial products, such as food supplements of high quality and low cost; (3) pharmacological applications.     

In vitro determination of digestible and unavailable protein in edible seaweeds

Edible seaweeds are considered a complementary source of food protein for human and animal nutrition. The physiological effects of seaweed protein depend on the degree of enzymatic digestion of protein in the small intestine and bacterial fermentation in the large intestine. The objective of this work was to estimate total, digestible, fermentable and unavailable protein in some red and brown seaweeds. Brown seaweeds Fucus vesiculosus, Laminaria digitata and Undaria pinnatifida and red seaweeds Chondrus crispus and Porphyra tenera were treated with pepsin and pancreatin to separate digestible protein. Residues containing indigestible protein were inoculated for 24 h with rat caecal droppings, and protein contents were evaluated in the non‐fermented residue. Protein content in the seaweeds ranged from 8.9 to 25% of dry matter. Digestible protein was the major protein fraction (69%) only in P tenera; in the other seaweeds, this fraction ranged from 15 to 45%. Significant amounts of unavailable protein were found in all samples (2–24%). The distribution of total protein among the three fractions, ie digestible, fermentable and unavailable protein, could yield information about the physiological and metabolic consequences of the intake of seaweed proteins. © 2002 Society of Chemical Industry     

全叶青兰提取物抗氧化活性的研究

以全叶青兰经超临界CO2萃取后的萃取物为原料,采用乙醇提取后,根据极性差异经乙醚、乙酸乙酯和正丁醇依次萃取,对所得提取物的抗氧化活性进行了研究。结果表明,3种提取物对DPPH自由基和羟基自由基均具有比较强的抗氧化活性。其清除DPPH自由基的能力比较接近,而对羟基自由基的清除能力三者差异较大。其中,乙酸乙酯和乙醚提取物清除羟基自由基的半数清除率要明显小于同等条件下的对照品芦丁和BHT的清除浓度,正丁醇提取物清除DPPH自由基的半数清除率的浓度明显要小于清除羟基自由基的浓度,乙酸乙酯萃取物和乙醚萃取物在两个体系内的差异较小。     

黑米花青苷胶囊体外清除自由基及抗氧化作用的研究

利用Fenton反应产生羟自由基、邻苯三酚在微碱条件下自氧化产生O-2、磷钼络合物法分别研究了黑米花青苷胶囊和黑米色素对羟基自由基、超氧阴离子的抑制和其总抗氧化活性。结果表明黑米花青苷胶囊和黑米色素能有效清除自由基,具有良好的抗氧化作用。其中黑米花青苷胶囊和黑米色素对羟自由基、超氧阴离子的抑制和其总抗氧化活性随着样品浓度增高而增加。黑米色素对羟自由基、超氧阴离子的抑制和总抗氧化活性显著高于黑米花青苷胶囊。     

瑶山梭罗果实不同提取部位的抗氧化活性研究

以乙醇为溶剂提取瑶山梭罗果实,经减压浓缩后,依次用乙酸乙酯和正丁醇进行萃取。用DPPH自由基的清除能力来评价2个部位的抗氧化活性。结果表明,乙酸乙酯部位浓度为280.80μg/mL时自由基清除率大于56%,IC50=210.21μg/mL,正丁醇部位浓度为368.00μg/mL时自由基清除率大于68%,IC50=291.03μg/mL。乙酸乙酯部位的抗氧化活性是正丁醇部位的1.4倍。     

干酪乳杆菌发酵8种食用豆提取物抗氧化活性研究

该试验分析了干酪乳杆菌（Lactobacillus casei）发酵8种食用豆总酚、总黄酮含量以及抗氧化活性的变化。结果表明,发酵前豇豆总酚含量最高,为（5.53±0.18） mg 没食子酸当量（GAE）/g干质量;红豆总黄酮含量最高,为（11.55±0.16） mg 芦丁当量（RE）/g干质量。发酵后绿豆总酚、总黄酮含量增加最高,分别为182.35%、27.84%;豇豆总酚含量、菜豆总黄酮含量下降最多,分别为43.40%、82.13%。发酵后豌豆提取物1,1-二苯基-2-三硝基苯肼（DPPH）自由基清除活性上升最显著,菜豆提取物下降最显著;绿豆提取物2,2'-联氮-双（3-乙基苯并噻唑啉-6-磺酸）二铵盐（ABTS）自由基清除活性上升最显著,菜豆提取物下降最显著;豌豆提取物铁离子还原能力上升最显著,菜豆提取物下降最显著。相关性分析结果显示,总酚、总黄酮含量与抗氧化活性均极显著相关（P＜0.01）。发酵对食用豆酚类物质含量和抗氧化活性影响显著,为开发不同食用豆功能食品提供理论基础。     

二氢杨梅素对4种植物油脂抗氧化作用研究

研究二氢杨梅素(DMY)对植物油脂抗氧化作用。采用紫外可见分光光度计和烘箱强化贮藏法,考察DMY对DPPH自由基清除能力和对山茶油、亚麻籽油、紫苏籽油和油酸的抗氧化作用。结果表明:DMY对DPPH自由基清除能力明显高于TBHQ、BHT、BHA和TP;当抗氧化剂添加量为0.05%时,不同抗氧化剂在山茶油和油酸中抗氧化作用强弱顺序为TBHQDMYBHABHTTP;不同抗氧化剂在紫苏籽油和亚麻籽油中抗氧化作用强弱顺序为TBHQBHABHTDMYTP;DMY还能协助增强其他抗氧化剂的作用;DMY对4种植物油脂抗氧化效果强弱顺序为山茶油油酸亚麻籽油紫苏籽油。     

石榴皮提取物的抗氧化作用研究

分别以水、甲醇、丙酮和乙酸乙酯为溶剂,对石榴皮中的多酚进行了提取,得到4种提取物。采用油脂过氧化值(POV)法和二苯三硝基苯肼(DPPH)自由基法研究了提取物的抗氧化活性。结果显示,4种提取物均具有抗油脂过氧化和清除DPPH自由基的能力,其抗氧化活性随添加量的增加而增加。4种提取物中,丙酮提取物的抗油脂过氧化作用最大,其次为水提取物和甲醇提取物,乙酸乙酯提取物的抗油脂过氧化作用最小。当丙酮提取物添加量为猪油质量的0.1%时,其抗油脂过氧化活性接近添加量为0.02%茶多酚或BHT。4种提取物对DPPH自由基的清除能力大小顺序依次为:水提取物、丙酮提取物、甲醇提取物和乙酸乙酯提取物。浓度为0.0175 mg/mL的水提取物对DPPH自由基的清除率高达85.2%,高于BHT,但略低于茶多酚。石榴皮多酚是一种有效的天然抗氧化剂。     

腐植酸钠清除自由基作用的研究

利用DPPH自由基清除法、羟自由基清除法、超氧阴离子自由基清除法、总还原力的测定4种方法对腐植酸钠的抗氧化活性进行了检测和评价。研究结果表明,腐植酸钠具有较强的自由基清除能力和一定的抗氧化能力,且随着腐植酸钠浓度的增加,其抗氧化能力逐渐增强。     

大果榕果实乙醇提取物抗氧化活性及对α-葡萄糖苷酶和乙酰胆碱酯酶抑制活性

研究大果榕果实的多酚含量及其抗氧化活性、α-葡萄糖苷酶和乙酰胆碱酯酶抑制活性,为其进一步开发利用奠定基础。以采自海南保亭七仙岭的大果榕果实为实验材料,用体积分数65%的乙醇提取大果榕果实多酚,采用Folin-酚法测定总酚含量。对获得的大果榕果实多酚进行1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基、2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)二铵盐(2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate),ABTS)自由基、羟自由基(·OH)清除率以及α-葡萄糖苷酶抑制活性和乙酰胆碱酯酶抑制活性测定。结果表明:大果榕果实多酚含量较高,达1.92 mg/g(以干质量计),其对DPPH自由基、ABTS+·和·OH均具有显著的清除活性,且呈质量浓度依赖性,IC50值分别为141.25、91.20、45.71μg/m L;大果榕果实多酚对α-葡萄糖苷酶抑制活性强于阳性对照阿卡波糖,且呈现明显的质量浓度依赖性,IC50值为102.33μg/m L;同时大果榕果实多酚对乙酰胆碱酯酶也具有一定的抑制活性,IC50值为4.9 mg/m L。研究结果表明大果榕果实多酚具有良好的抗氧化性、α-葡萄糖苷酶抑制活性和一定的乙酰胆碱酯酶抑制活性。     

Radical Scavenging Capacity and Antioxidant Activity of the E Vitamer Fraction in Rice Bran

ABSTRACT: Radical scavenging capacity and antioxidant activity of an E vitamer fraction from rice bran were investigated. The E vitamer fraction was prepared by a liquid-liquid extraction method. The free radical scavenging capacity of the E vitamer fraction was measured by the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) method at the concentration range of 2.5 to 640 ppm, whereas the antioxidant activities were measured by both the reducing power and ferric thiocyanate (FTC) methods at different concentrations (0, 2.5, 10, 40, and 160 ppm). Radical scavenging capacity of the fraction was effective up to 160 ppm, then remained stable. Also, at a concentration of 160 ppm, it was highly effective in inhibiting linoleic acid peroxidation. Similarly, superoxide scavenging and antioxidant activities of the E vitamer fraction were compared with those of the synthetic phenol compounds. Results showed that with a concentration of the E vitamer fraction at 160 ppm, the antioxidant activity was comparable to both butylated hydroxytoluene (BHT, 160 ppm) and butylated hydroxyanisole (BHA, 160 ppm). No significant differences (P > 0.05) were found among them. The E vitamer fraction may be a good substitute for the synthetic phenol antioxidants currently used in industry because the former is more natural and comparatively effective in its radical scavenging capacity and antioxidant activity.     

干燥方式对金银花多酚组分及其抗氧化活性的影响

研究传统热风干燥、自然阴干以及真空干燥、真空冷冻干燥等不同干燥方式对金银花多酚类物质含量及抗氧化活性的影响。采用Folin-酚比色法及高效液相色谱（high performance liquid chromatography,HPLC）法分别检测4 种干燥方式下的金银花总酚及多酚类组分含量,并比较其清除1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基、羟自由基（•OH）和2,2’-二氮-双（3-乙基苯并噻唑-6-磺酸）铵盐（2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonate acid) diammonium salt,ABTS）自由基的能力。结果表明：4 种干燥方式对金银花总酚含量及多酚类组分均有一定影响,其中真空冷冻干燥处理时金银花总酚及多酚类组分损失最小;不同干燥方式对金银花的抗氧化能力影响显著（P＜0.05）,真空冷冻干燥样品清除DPPH自由基、•OH和ABTS＋•的半抑制浓度（IC50）分别为5.43、17.64、44.32 μg/mL;而自然阴干、真空干燥和热风干燥处理的样品清除DPPH自由基、•OH及ABTS＋•的IC50高于真空冷冻干燥金银花相应的IC50。相关性分析显示,金银花酚酸类组分与其抗氧化活性显著相关（P＜0.05）。因此,真空冷冻干燥能较好地保留金银花多酚类物质,且具有较强的抗氧化活性,适宜用于金银花的干燥。