花生衣粉与洋葱粉提高面包抗氧化功能的对比

比较不同添加量的花生衣粉、洋葱粉对提高面包抗氧化功能的差异。利用福林-酚法测定面包的总酚含量,利用 pH 示差法测定总花青素含量,分析面包的·OH清除能力、DPPH 自由基清除能力以及总抗氧化性。结果表明,当花生衣粉、洋葱粉添加量达到5%时,面包中的总花青素及总酚含量、·OH清除能力、DPPH 自由基清除能力以及总抗氧化性均得到较大幅度的提高,抗氧化功能中的 DPPH 自由基清除率随着添加量增加的提高最为明显。花生衣粉面包的总花青素含量比相同添加量的洋葱粉面包更高,花生衣粉面包的·OH清除能力、DPPH自由基清除能力均优于洋葱粉面包。当添加量为6%时,两种面包的总花青素及总酚含量增幅减缓,且抗氧化功能开始下降。考虑经济性及抗氧化效果,面包中的花生衣粉、洋葱粉添加量应取5%,花生衣粉提高面包的抗氧化功能优于洋葱粉。     

茶多酚对面包品质及面包酚类物质抗氧化能力的影响

研究了不同茶多酚添加量对面包比容以及品质的影响,通过ABTS~+自由基清除率(ABTS法)和DPPH~+自由基清除率(DPPH法)探讨了茶多酚对面包总酚含量的影响及其抗氧化性变化。研究结果表明,茶多酚的添加对面包比容无显著性影响(P0.05),通过对面包质构分析,添加0.15%茶多酚对面包品质有一定改善,此时面包口感较好、呈有弹性;茶多酚的添加使面包总酚含量显著增加(P0.05),增强了ABTS~+自由基清除率和DPPH~+自由基清除率。当茶多酚添加量为0.15%,面包皮的ABTS~+自由基和DPPH~+自由基清除率分别增加了26.68%、69.85%,面包芯的自由基清除率分别提高了29.06%、61.18%。此外,面包皮相比于面包芯的抗氧化能力高,这是由于面包皮中美拉德产物具有抗氧化性。研究为通过日常饮食预防退行性疾病提供一定指导。     

添加黑米酒糟对面包品质与功能特性的影响

以黑米酒糟制备面包，依据感官评价、面包测定指标等探究不同添加量的黑米酒糟对面包品质的影响，并通过体外实验方法，分析黑米酒糟对面包的抗氧化和体外消化特性的影响。结果表明，不同添加量的黑米酒糟对面包比容、色泽品质、质构及感官等影响显著。随着黑米酒糟添加量增加，面包的总酚含量(14%～28%)、DPPH自由基清除率(40.8%～52.5%)和ABTS阳离子自由基清除率(16.8%～53.9%)明显增加，表明其能显著提高面包的抗氧化性。此外，黑米酒糟能降低面包中快速消化淀粉和慢速消化淀粉含量，提高抗性淀粉含量，表明其能明显降低面包的体外消化能力，适用于制备抗性淀粉制品。     

发芽糙米提取物抗氧化性及活性成分分析

对发芽糙米不同极性溶剂提取物的抗氧化活性及其成分进行分析,将发芽糙米分别用蒸馏水、甲醇、无水乙醇、丙酮、石油醚进行提取,采用DPPH自由基清除率、羟基自由基清除率、超氧阴离子自由基清除率和铁离子还原能力为指标进行抗氧化活性评价,同时探究不同极性溶剂提取物中总酚、总黄酮、γ-氨基丁酸、糖蛋白和多糖的含量及其对抗氧化活性的影响。结果表明：发芽糙米不同极性溶剂提取物均具有抗氧化活性,并呈现一定的量效关系。发芽糙米的蒸馏水提取物的DPPH自由基清除率、羟基自由基清除率和铁离子还原能力较高,而无水乙醇提取物的超氧阴离子自由基清除率较高。发芽糙米的甲醇、丙酮提取物中多糖含量最高,蒸馏水、无水乙醇、石油醚提取物中糖蛋白含量最高。表明不同溶剂提取物中多糖和糖蛋白含量对自由基清除活性和铁离子还原能力均具有较大的影响。     

温莪术不同溶剂提取物体外抗氧化活性评价

目的:探讨温莪术不同溶剂提取物体外的抗氧化活性。方法:分别用蒸馏水、95%乙醇、乙酸乙酯等不同极性溶剂提取温莪术中活性物质,采用清除1,1-二苯基-2-三硝基苯肼(DPPH)自由基、羟自由基(.OH)、亚铁离子螯合和还原能力等方法考察温莪术不同提取物的抗氧化活性。同时用Folin-Cioeaile法测定不同提取物中的总酚含量,考察总酚含量与抗氧化清除率的关系。结果:DPPH自由基、.OH清除能力及还原能力结果表明95%乙醇及乙酸乙酯提取物在较低的质量浓度显示了较高的清除率;同时总酚含量测定结果显示95%乙醇和乙酸乙酯提取物所含总酚含量较高,这表明这两种溶剂提取物的抗氧化性与其提取物含有较高的酚类密切相关;亚铁离子螯合实验结果显示水提物的螯合效果优于其他溶剂提取物。结论:不同溶剂提取物抗氧化能力差别较大,总酚含量与抗氧化清除率具有相关性。     

一株八角内生真菌发酵液抗氧化活性研究

以乙酸乙酯和水饱和正丁醇为萃取溶剂,对八角内生真菌BJEF13的发酵液进行连续萃取,获取不同极性萃取物。对发酵原液(BR)、乙酸乙酯萃取物(EE)、正丁醇萃取物(BE)以及水残余物(WE)的总抗氧化性、DPPH自由基清除率、超氧阴离子自由基清除率、羟基自由基清除率以及总黄酮、总酚含量进行了测定。结果表明:各提取物都具有一定的抗氧化活性,并呈量效关系。各提取物抗氧化活性顺序为:EEBEBRWE。EE的抗氧化活性最强,其清除DPPH、超氧阴离子、羟基自由基的IC50分别为38、73、50μg/m L。BR、EE、BE和WE中总黄酮的含量分别为5.65%、30.21%、11.59%和1.54%,总酚含量分别为20.43%、55.01%、60.82%和10.71%,总黄酮含量和总酚含量大小与抗氧化活性顺序基本相符。     

连翘叶不同溶剂提取物体外抗氧化活性研究

比较连翘叶不同提取溶剂提取物的抗氧化活性。分别以水、60%乙醇、80%乙醇、无水乙醇、乙酸乙酯为溶剂制备连翘叶提取物,测定不同提取物中多糖、总酚和黄酮含量;以BHT为阳性对照,采用DPPH自由基(DPPH·)、羟基自由基(·OH)、超氧阴离子(O_2~-·)、ABTS自由基(ABTS~+·)清除活性和铁离子还原能力(FRAP)法考察各溶剂提取物的抗氧化活性;考察提取物中活性物质含量与其活性的相关性。连翘叶不同溶剂提取物均具有抗氧化活性,均呈一定的量效关系,且不同溶剂提取物的抗氧化活性强弱顺序随评价方法的不同而不同。连翘叶不同溶剂提取物中总酚含量和黄酮含量均与·OH清除活性和铁离子还原能力具有较高的相关性,黄酮含量还与O_2~-·清除活性具有较高的相关性。连翘叶80%乙醇提取物和60%乙醇提取物抗氧化活性相对较高。     

沙葱不同部位提取物总黄酮含量及其体外抗氧化、抗菌活性研究

以沙葱花、叶、秆提取物为对象,研究沙葱不同部位提取物中总黄酮含量、还原能力、清除DPPH自由基能力、体外清除羟基自由基能力以及体外对大肠埃希氏菌、金黄色葡萄球菌、绿脓杆菌和沙门氏菌的抑菌作用。结果表明:沙葱不同部位提取物总黄酮含量最高的为沙葱叶提取物,且各提取物均有一定的体外抗氧化与抗菌作用,其中沙葱叶提取物体外抗氧化及抗菌活性较好,对DPPH自由基的清除率可达52.2%、对羟基自由基的清除率可达84.4%。     

黄参不同溶剂提取物抗氧化活性研究

采用DPPH抗氧化、对羟基自由基致DNA氧化损伤保护的评价方法,研究了黄参正己烷提取物、二氯甲烷提取物、乙酸乙酯提取物以及甲醇提取物的抗氧化活性的差异。结果表明,黄参不同溶剂提取物均对DPPH自由基具有很好的清除作用,并且能够较好的保护DNA防止羟基自由基对其的损伤,但是不同溶剂提取物的抗氧化能力存在显著差异;在不同溶剂的黄参提取物中,甲醇的提取率最高,但乙酸乙酯提取物的抗氧化活性最强并且其总酚含量最高。在对DPPH自由基清除试验中,溶剂提取物其总酚含量和抗氧化性的趋势不一致,说明在黄参提取物中除酚类物质外,还存在其它的抗氧化物质。结合Folin-Ciocalteu、DPPH自由基清除率法和DNA损伤保护法分别测定黄参不同溶剂提取物中总酚的含量和抗氧化力,可初步评价黄参的抗氧化特性。     

小叶丁香皮不同溶剂提取物的抗氧化活性

目的:研究小叶丁香皮中不同溶剂提取物的抗氧化活性。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小叶丁香皮的总提液、乙酸乙酯层、正丁醇层和石油醚层在不同质量浓度下的抗氧化能力及总酚含量。结果:小叶丁香皮的不同溶剂提取物对DPPH自由基均具有较强的清除能力及还原能力,其清除率与质量浓度呈良好的量效关系。其中正丁醇层抗氧化能力最强,在质量浓度0.62mg/mL时,对ABTS+.的最大清除率为96.28%,对DPPH自由基的最大清除率为96.16%,与同质量浓度VC的清除率接近,且其IC50分别为0.074、0.012mg/mL;测得的正丁醇层总酚含量最高,为120.1μg/20mg。结论:小叶丁香具有较好的抗氧化能力,其正丁醇层抗氧化能力显著,这与总酚含量有较大的相关性。     

Antioxidant and tyrosinase inhibitory activities of different parts of guava (<Emphasis Type="Italic">Psidium guajava</Emphasis> L.)

The antioxidant and the tyrosinase inhibitory activities of 4 different solvents (acetone, ethanol, methanol, and water) for preparation of extracts from guava (branch, fruit, leaf, and seed) were evaluated by measuring total phenolic contents (TPC), DPPH radical scavenging activity, ABTS radical scavenging activity, reducing power (RP), and tyrosinase inhibitory activity. The extracts of branch and leaf showed relatively higher antioxidant properties than those of fruit and seed. The highest TPC (141.28 mg/g gallic acid equivalents), DPPH radical scavenging activity (IC₅₀=34.01 μg/mL), ABTS radical scavenging activity (IC₅₀=3.23 μg/mL), and RP (IC₅₀= 75.63 μg/mL) were found in acetone extract of leaf, while water extract of seed had the lowest antioxidant activity. The tyrosinase inhibitory activity of ethanol extract from guava leaf was 69.56%, which was the highest activity among the extracts. These results indicate that useful bioactive substances exist in the guava branch as well as leaf extracts.     

Antioxidant Fraction from Bark of Dillenia Indica

Barks of various plants have been reported to possess both in vitro and in vivo antioxidant activity. In this study, antioxidant activity of the extract from the barks of Dillenia indica was evaluated by various in vitro methods. The bark of D. indica was extracted with 70% aqueous acetone. The total phenolic content was determined by Folin-Ciocalteu method and the antioxidant activity was assayed through various in vitro methods such as antioxidant capacity by phosphomolybdenum method, radical scavenging activity using α, α-diphenyl-β-picrylhydrazyl method, hydroxyl radical (^?OH) scavenging activity by deoxyribose method, and superoxide anion (O₂ ^??) scavenging activity by phenazine methosulphate/NADH-nitroblue tetrazolium system. The total phenolic content of the extract as tannic acid equivalents was 54%. The total antioxidant capacity of the extract was found to be 3.12 mmoles/g as equivalent to ascorbic acid at 50 ppm concentration. At 25 ppm concentration, the radical scavenging activity of butylated hydroxyanisole and extract showed 90.9% and 91.0%, respectively. The ^?OH scavenging activity of the extract was shown to be 53.9% at 100 ppm concentration. At a concentration of 50 μg, the O₂ ^?? scavenging activity of the extract was 31.7% as compared to 47.7% by gallic acid. These results indicated that Dillenia indica barks contained large amount of phenolics and possessed potent antioxidant property.     

In Vitro Antioxidant and Antiglycation Properties of Methanol Extract and Its Different Solvent Fractions of Musa paradisiaca L. (Cv. Nendran) Inflorescence

Methanolic extract of Musa paradisiaca inflorescence and its different solvent fractions, petroleum ether, ethyl acetate, butanol, and water were studied for their total phenolic and flavonoid content, free radical scavenging, and antiglycation activities, and these properties were compared with standard antioxidant compounds. Ethyl acetate fraction exhibited higher antioxidant and antiglycation properties than other fractions. IC₅₀ values of ethyl acetate fraction for 1,1-diphenyl-2-picrylhydrazyl method, 2,2-azinobis-3 ethylbenzothiazoline-6-sulphonic acid method, superoxide radical scavenging, hydroxyl radical scavenging, nitric oxide radical scavenging, and antiglycation activities were 9.80, 13.50, 26.40, 19.71, 25.73, and 31.00 μ g/ml, respectively. Total phenolic content of ethyl acetate (21.52 mg GAE/g) was significantly higher than other fractions. There was positive linear correlation between antioxidant activity and total phenolic content.      

Study on antioxidant activity of certain plants in Thailand: Mechanism of antioxidant action of guava leaf extract

The ethanol extracts from 24 samples plant species commonly found in Thailand were investigated and compared on their antioxidant activity by ABTS assay. The ethanol extract from the leaves of guava (Psidium guajava) showed the highest antioxidant capacity with the TEAC value of 4.908 ± 0.050 mM/mg, followed by the fruit peels of rambutan (Nephelium lappaceum) and mangosteen (Garcinia mangostana) with the TEAC values of 3.074 ± 0.003 and 3.001 ± 0.016 mM/mg, respectively. The further investigation of guava leaf extracts from different solvents; n-hexane, ethyl acetate, n-butanol, and methanol, was examined using ABTS and FRAP assays. The total phenolic content was done by Folin–Ciocalteu reaction. The results indicated that the methanol fraction possessed the highest antioxidant activity, followed by the butanol and ethyl acetate fractions, respectively. The hexane fraction showed the lowest antioxidant activity. The results demonstrated that the mechanism of antioxidant action of guava leaf extracts was free radical scavenging and reducing of oxidized intermediates. The phenolic content in guava leaf fraction played a significant role on the antioxidant activity via reducing mechanisms.     

Assessment of the Antioxidant and Free Radical Scavenging Activities of Methanolic Extract of Diplazium esculentum

The present study was carried out to determine the antioxidant and different free radical scavenging activities of 70% methanolic extract of Diplazium esculentum. Total antioxidant activity of the extract was evaluated as trolox equivalent antioxidant capacity value. The IC₅₀ values for scavenging of different free radicals indicated its efficient free radical scavenging properties. The extract acted as an iron chelator and also possessed reducing power. It also inhibited lipid peroxidation. Moreover, the extract yielded high phenolic and flavonoid content. Therefore, the results indicated that 70% methanolic extract of D. esculentum acted as a potential antioxidant and free radical scavenger.     

Liaison of phenolic acids and biological activity of escalating cultivars of Daucus carota

The objective of the present study was to analyze and compare the phenolic compounds and their antioxidant capacities of new lines of Dacus carota. The selected cultivars showed high variation in the contents of total phenolics (30.26–65.39 mg/100 g FW) and total ascorbic acid (41.12–58.36 mg/100 g FW). Analysis on RP-HPLC revealed that hydroxycinnamic acids and its derivatives were major phenolic compounds present in D. carota extracts, whereas 5-caffeolquinic acid was a major hydroxycinnamic acid (ranged from 30.26 to 65.39 mg/100 g FW). DCP cultivar showed high total antioxidant capacity (77.69 mg/100 g), 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity (52.36 mg/100 g), superoxide radical scavenging capacity (53.69 mg/100 g), and hydroxyl radical scavenging capacity (51.91 mg/100 g). A linear relationship was found between total phenolic acid contents and antioxidant capacity. Both phenolic compounds and antioxidant capacities varied significantly (ρ < 0.05) among cultivars. DCP cultivar was found to be a rich source of phenolics and ascorbic acid with high antioxidant activity.     

Flavonol content in the water extract of the mulberry (Morus alba L.) leaf and their antioxidant capacities

Abstract: The biological activities of the mulberry (Morus alba L.) leaf have been attributed to its flavonoid content. The water extract of the mulberry leaf (WEML) was prepared by autoclaving at 121 °C for 15 min, and the flavonol content of the WEML was determined by HPLC The WEML contained 4 flavonols in the following order: quercetin‐3‐β‐D‐glucose (QT‐G) > quercetin‐3‐O‐glucose‐6″‐acetate (QT‐GA) > rutin (RT) > quercetin (QT). In the oxygen radical absorbance capacity (ORAC) assay, QT had the highest peroxyl radical‐scavenging capacity and a similar hydroxyl radical‐scavenging capacity as its glycosides (QT‐G, QT‐GA, and RT). QT exhibited a stronger cellular antioxidant capacity (CAC) against 2,2′‐Azobis(2‐amidinopropane) dihydrochloride (AAPH)‐ and Cu²⁺‐induced oxidative stress in HepG2 cells compared to its glycosides, indicating that the intracellular antioxidant capacity of QT and its glycosides may depend upon both the permeability across the cell membrane and the peroxyl or hydroxyl radical‐scavenging capacity. Practical Application: The information presented might be used for developing mulberry leaf‐based functional foods.     

Antioxidant activities of red pepper (Capsicum annuum) pericarp and seed extracts

In this study, we examined the antioxidant activities of red pepper (Capsicum annuum, L.) pericarp and red pepper seed extracts. The extracts were evaluated by various antioxidant assays, including 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging, superoxide anion radical scavenging, hydroxyl radical scavenging, [2,2′‐azino‐bis(3‐ethylbenzthiazoline‐6‐sulphonic acid)] (ABTS) radical scavenging, ferrous chelating activity, superoxide dismutase (SOD) activity and reducing power, along with the determination of total phenolic and flavonoid contents. All the extracts showed strong antioxidant activity by the testing methods. The red pepper pericarp extract exhibited strong ferrous chelating activity and high scavenging activity against free radicals, including both the hydroxyl and DPPH radicals, but it exhibited weaker scavenging activity for the superoxide anion radical and for SOD. In contrast, the red pepper seed extract exhibited strong SOD activity and high scavenging activity against the superoxide anion radical, but showed weaker ferrous chelating activity, hydroxyl radical scavenging, and DPPH radical scavenging. We observed that the reducing power level and ABTS radical scavenging activity of the red pepper seed were higher than those of the red pepper pericarp at the highest tested concentration. Most of the test results for the red pepper seed and red pepper pericarp extracts increased markedly with increasing concentration; however, the metal chelating, SOD and ABTS radical scavenging activities did not increase with the concentration. Highest total phenolic and flavonoid contents were obtained from the red pepper pericarp extracts. Overall, the red pepper seed and red pepper pericarp extracts were highly effective for the antioxidant properties assayed, with the exceptions of ferrous chelating activity, hydroxyl radical scavenging and SOD activity.