溪黄草根不同溶剂提取物的抗氧化性

考察7种溶剂(蒸馏水、60%乙醇、无水乙醇、甲醇、丁醇、氯仿和乙酸乙酯)对溪黄草根中可溶出成分的提取效果,研究7种提取物总酚含量、清除DPPH自由基能力、清除ABTS+ ·能力和螯合Fe2+的能力。结果表明：水和60%乙醇对溪黄草根中可溶出成分的提取效果最好;60%乙醇提取物总酚含量最高,清除DPPH自由基能力最高(超过迷迭香提取物、竹叶提取物、抗坏血酸棕榈酸酯),清除ABTS+ ·能力最好(超过迷迭香提取物),并具有较强的螯合Fe2+能力(超过迷迭香提取物、竹叶提取物、抗坏血酸棕榈酸酯)。     

苹果皮不同溶剂提取物抗氧化活性研究

研究苹果皮不同溶剂提取物的抗氧化活性。依次用蒸馏水、60%乙醇、无水乙醇、乙酸乙酯提取苹果皮中的活性物质,用Folin-Ciocalteu法测定提取物中总酚含量,并以Vc为阳性对照,通过测定对羟自由基(.OH)、超氧阴离子自由基(O2-.)、亚硝酸盐(NO2-)的清除作用及总还原力,比较评价4种提取物的抗氧化活性。苹果皮60%乙醇提取物总酚含量显著高于其他提取物;在不同的抗氧化体系中,苹果皮的4种不同溶剂提取物均具有不同程度的抗氧化活性且与质量浓度呈明显的量效关系,60%乙醇提取物的抗氧化活性始终最强,其清除.OH和O2-.活性弱于Vc,而清除NO2-活性和还原能力较强且高于Vc。苹果皮抗氧化活性物质主要是60%乙醇提取物。     

蜂胶不同溶剂萃取物组成和抗氧化性的研究

以蜂胶为原料,分别以甲醇、乙醇、氯仿、蒸馏水为溶剂进行萃取,测定各萃取物总酚与黄酮类物质的含量,通过测定还原能力,清除DPPH 自由基能力的测定来比较4 种不同萃取物的抗氧化性。结果表明：甲醇萃取物具有较强的抗氧化性。甲醇萃取物浓度为0.25mg/ml 时还原力高达1.162,且浓度为0.05mg/ml 时对DPPH 自由基清除率为64.676%。乙醇萃取物通过石油醚、氯仿、乙酸乙酯、丙酮依次分级萃取后所得到4 种萃取物各项指标测定结果表明,氯仿萃取了蜂胶乙醇萃取物中主要成分,但乙酸乙酯和丙酮萃取物的还原能力及清除DPPH 自由基清除能力较佳,在浓度为0.05mg/ml 时还原力分别为2.087 和1.798,DPPH自由基清除率达87.724% 和88.013%。     

Rapid Fruit Extracts Antioxidant Capacity Determination by Fourier Transform Infrared Spectroscopy

ABSTRACT: The antioxidant content of fruits have made them a desirable component of the human diet. Several wet chemistry techniques, including the oxygen radical absorbance capacity (ORAC_FL) assay, have been reported for measuring the antioxidant activities of fruit. In this study, we investigated the use of Fourier transform infrared spectroscopy (FTIR) to measure fruit antioxidant activity. Flavonoid-rich extracts from 5 blueberry, 5 grape, and 6 blackberry genotypes were obtained by methanol-water-formic acid (60:37:3, v/v/v) solvent. The total antioxidant capacities of the fruit extracts were determined by the ORAC_FL assay, and the FTIR spectra of the fruit extracts were collected. Partial least squares (PLS) regressions with cross-validation was conducted on 128 spectra of extracts and their corresponding ORAC_FL values to obtain a calibration model for predicting the antioxidant activity of the extracts. Spectra from an additional 16 extracts were used as an external validation set for the model. A good calibration model ( R ²= 0.97) for antioxidant activity was obtained with satisfactory predictive ability (root mean standard error [RMSE] = 5.35) using the spectral region 2000/cm to 900/cm. Cross-validation procedures indicated good correlations ( R ²= 0.94) between ORAC_FL assay values and FTIR estimates. The ratio of the standard deviation of the data to the standard error of validation (RPD) values were above 5.0 for blueberry, grapes, and the combined extracts in the external validation set indicating that the calibration model was suitable for quantifying fruit extracts antioxidant activities. This study shows that an FTIR technique would be suitable for rapidly measuring fruit extract antioxidant activity.     

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。     

不同品种石榴花色苷、总多酚含量及抗氧化活性比较研究

石榴中含有丰富的花色苷和多酚类物质,具有良好的抗氧化活性。以5个石榴品种(大叶天红蛋、大红酸、净皮甜、御石榴和喀什红子酸石榴)为实验材料,分析其总花色苷、总多酚含量,并用DPPH、FRAP、ABTS、螯合亚铁离子法测定抗氧化活性,比较不同石榴品种总花色苷、总多酚含量及抗氧化活性。结果表明:不同石榴品种总花色苷含量范围为3.54～13.89mg/100g,总多酚含量范围为38.89～68.28mg/100g;清除DPPH自由基范围为24.30%～45.73%;FRAP法测得的还原力范围为0.38～0.78;清除ABTS+.能力范围为58.02%～83.40%;螯合亚铁离子能力范围为14.73%～70.60%。相对而言,喀什红子酸石榴抗氧化活性较好,其次为御石榴。     

红豆越橘不同溶剂萃取物组成及抗氧化相关性

以矮丛红豆越橘为研究对象,用体积分数95%乙醇提取后,分别用石油醚、乙酸乙酯、正丁醇进行萃取,评价乙醇粗提取物和不同溶剂萃取物中总酚、总黄酮、总花色苷、齐墩果酸含量及体外抗氧化能力(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)二铵盐自由基(2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate),ABTS~+·)清除能力)。红豆越橘粗提取物及不同溶剂萃取物均具有一定的抗氧化活性,其中乙酸乙酯、正丁醇萃取物的抗氧化活性较强,乙酸乙酯萃取物具有最好的DPPH自由基清除能力(半抑制浓度(50%inhibitory concentration,IC_(50))为0.27 mg/m L)与ABTS+·清除能力(IC_(50)为0.05 mg/m L)。不同溶剂萃取物的抗氧化活性与总黄酮和总酚的含量具有较强的相关性。     

覆盆子醇提物及其不同极性部位抗氧化活性研究

以覆盆子醇提物及其不同极性部位的总酚、黄酮含量和抗氧化活性为研究目的,采用还原力,1,1-二苯基-2-苦基肼(DPPH)和OH自由基清除能力抗氧化体系来评价它们的抗氧化活性,研究结果表明:乙酸乙酯相的总酚和黄酮含量最高,分别为(328.33±13.75)mg/g和(298.25±25.64)mg/g(p<0.05);该相在不同抗氧化体系中的抗氧化活性也最强,清除DPPH和OH的能力显著强于BHT(p<0.05)。覆盆子醇提物及其不同极性部位中的总酚含量与还原力,DPPH和OH清除能力呈正相关,相关系数分别为0.9197、0.9321和0.9808,这表明总酚是覆盆子提取物的主要抗氧化活性成分。     

Antioxidant capacity changes of 3 cultivar Chinese pomegranate (Punica granatum L.) juices and corresponding wines

This study investigated the antioxidant capacities that included Ferric reducing antioxidant power (FRAP), 1, 1-diphenyl-2-picryl hydrazine (DPPH), ·OH and O(2·)(-)-scavenging abilities, total polyphenols (TP) and total anthocyanins (TA) in pomegranate (Punica granatum L.) juice (PJ) and pomegranate wine (PW). The correlations among them were also analyzed. Both PJ and PW showed significantly high TP and antioxidant capacities, but some differences existed among these cultivars. There was 1596.67 mg/L TP found in sweet PJ, while sour PJ showed the highest titratable acidity of 35.90 g/L and lowest pH value at 2.56. Red PJ was found to have the highest TA (82.26 mg/L) in the 3 cultivars. Sweet PJ showed higher DPPH-scavenging ability and higher FRAP than others. Both PJ and PW exhibited high and relatively stable ·OH-scavenging abilities, in which sour PJ and sour PW had higher O(2·)(-) scavenging capacity than others. Significant positive correlations were observed among TP, DPPH, and FRAP in both PJ and PW. A high correlation between antioxidant capacities and TP indicated that phenolic compounds were major contributors to the high antioxidant activity of PJ and PW.     

葡萄醋抗氧化活性比较研究

分别以4个品种(巨峰、京亚、藤稔、美丽)的葡萄果实为原料,采用液态深层发酵法酿造葡萄醋,对发酵产物(醋及其酒醪)的总抗氧化能力、还原能力、清除DPPH自由基能力进行测定和比较分析,结果表明：葡萄醋有比较强的抗氧化活性;葡萄醋及其酒醪的抗氧化活性在品种间差异很大,藤稔葡萄的发酵产物抗氧化活性最强,美丽葡萄最弱;葡萄醋的抗氧化活性与总多酚和黄酮含量呈极显著(P＜0.01)的相关性。     

Antioxidant Activity of Ripe and Unripe Pepino Fruit (Solanum muricatum Aiton)

Abstract: Ripe and unripe exotic pepino fruit were evaluated for antioxidant activity, total phenols, and flavonoid content. The antioxidant potency was investigated by employing various established in vitro systems, such as 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH), 2–2′‐azinobis(3‐ethylbenthiazoline‐6‐sulphonic acid (ABTS), hydroxyl radical scavenging, reducing power, ferrous ion chelation, ferric reducing antioxidant power (FRAP), and lipid peroxidation. The EC₅₀ values of ripe ethanolic extract on DPPH radical, reducing power, ferrous ion chelation, ABTS radical, FRAP, hydroxyl radical, lipid peroxidation (brain), and lipid peroxidation (liver) were obtained to be 2.20, 2.81, <5.00, 34.06, 8.53, 1.30, 1.75, and 0.51 mg/mL, respectively. However, the EC₅₀ values for unripe fruit extract were noted to be 3.75, 3.40, 11.25, 40.12, 9.75, 0.80, 1.91, and 0.63 mg/mL, respectively. Ripe fruit exhibited the highest values of antioxidant activity in all the scavenging assays except for hydroxyl radical scavenging assay. Ripe pepino had higher total phenol and flavonoid content than unripe fruit. This study suggests that possible mechanism of the biological activities may be due to free radical scavenging and antioxidant characteristics, which may be due to the presence of polyphenols in the fruit extracts. Practical Application: The ripe and unripe pepino fruit have excellent antioxidant properties, so the results obtained in this study clearly indicate that pepino fruit has a significant potential to use as a natural antioxidant agent and possibly as a food supplement.     

重庆地方名柚果肉酚类物质含量及其抗氧化活性分析

通过紫外分光光度计法和高效液相色谱法分别测定10 种重庆地方名柚成熟果实囊衣、汁胞2 个部位的总酚、总黄酮含量及类黄酮、酚酸组分和含量,并采用1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）、铁离子还原能力（ferric reducing antioxidant power,FRAP）测定、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）3 种方法对其抗氧化活性进行评价。结果表明：囊衣的总黄酮含量和类黄酮含量较高,‘琯溪蜜柚’总黄酮含量最高达10.97 mg/g,类黄酮中地奥司明含量最高,均值为1 000.72 μg/g,其含量最高为‘五布柚’,达到2 366.77 μg/g;汁胞的总酚含量和酚酸含量较高,‘真龙柚3号’总酚含量最高达8.84 mg/g,酚酸中没食子酸含量最高,均值为1 040.16 μg/g,其含量最高为‘长寿沙田柚’,达到1 325.89 μg/g。利用DPPH法和FRAP法测定2 个部位抗氧化活性,汁胞高于囊衣,ABTS法则囊衣高于汁胞。综合抗氧化能力指数表明,‘琯溪蜜柚’囊衣、‘梁平柚78-8’汁胞的抗氧化活性最强。通过本研究,不仅能够了解重庆地方名柚果实囊衣、汁胞部位酚类物质组分和含量,同时为柑橘酚类物质的应用选择提供了一定的理论依据,促进了柑橘果品营养学的发展。     

绞股蓝中6 种多酚化合物的HPLC检测及其醇提液的抗氧化活性

采用高效液相色谱法分析野生（5 叶、7 叶和9 叶3 种生态类型）和人工种植（7 叶）绞股蓝的叶及茎中6 种多酚化合物的含量,并测定样品醇提液的总多酚含量及抗氧化活性。结果表明：色谱条件为色谱柱poroshell 120 PFP（4.6 mm×100 mm,2.7 μm）,流动相1%甲酸（A）和乙腈（B）,检测波长254 nm和350 nm,在此条件下绞股蓝样品中6 种多酚单体可在35 min内得到较好分离,且重复性好（相对标准偏差（relative standard deviation,RSD）≤4.6%）、精密度高（RSD≤2.68%）、稳定性好（RSD≤2.45%）、加标回收结果准确可靠（平均回收率84%～99%,RSD≤4.02%）。6 种多酚单体在不同的绞股蓝样品中含量差异较大,但均呈现出芦丁含量最高,对羟基苯甲酸含量最低。绞股蓝样品醇提液中总多酚及抗氧化活性在不同样品间差异较大,在野生绞股蓝（7 叶）叶中最高（分别为75、39.65、70.48 mg/g）,在其茎中最低（分别为2.81、2.1、3.7 mg/g）。总体而言,绞股蓝的叶中总多酚含量高于茎中,醇提液的抗氧化活性也强于茎。     

烘焙条件对小粒黑豆中抗氧化组分及抗氧化活性的影响

小粒黑豆的抗氧化作用与其所含有的酚类、花色苷的含量等密切相关,而这些物质在加工过程中会受温度和时间的影响而发生变化。实验以盐池黑豆、府谷小黑豆两种小粒黑豆为材料,分析烘焙处理对其总酚、花色苷含量、总抗氧化能力及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）、超氧阴离子自由基（O2－·）清除能力的影响。结果表明,烘焙对小粒黑豆的抗氧化活性有显著影响,200 ℃条件下烘焙后的总酚含量显著高于100、150 ℃,150 ℃的总酚含量最低;总花色苷含量随着烘焙温度的升高、处理时间的延长而显著减少;·OH清除作用随着烘焙温度的升高而显著降低;烘焙样品的O2－·清除作用显著低于未烘焙样品（P＜0.05）。盐池黑豆、府谷小黑豆的总酚含量、总抗氧化能力以及DPPH自由基、O2－·的清除作用在150 ℃时最低。200 ℃条件下烘焙30 min,盐池黑豆的总酚含量、总抗氧化能力、DPPH自由基清除率最高;府谷小黑豆在200 ℃条件下烘焙40 min,其总酚含量最高,而100 ℃条件下烘焙20 min时的花色苷含量、总抗氧化能力、DPPH自由基清除率最高。     

不同解冻方法对速冻桑葚汁液流失率、理化品质及抗氧化活性的影响

为减少速冻桑葚在解冻过程中的汁液流失率、缩短解冻时间和减少其色泽的变化,增加解冻桑葚的营养物质和抗氧化活性的保留量,采用微波功率500 W解冻、微波功率550 W解冻、超声波解冻、冷藏解冻、室温解冻进行速冻桑葚的解冻实验。结果表明:微波功率500 W解冻和微波功率550 W解冻的解冻时间较短,分别为0.58 min和0.35 min,冷藏解冻的解冻时间最长为305 min。不同解冻方法的汁液流失率存在显著差异,微波功率500 W解冻的汁液流失率最低,为1.34%;超声波解冻的汁液流失率最高,为9.24%。微波功率500 W解冻桑葚的总酚含量(151.66 mg/100 g)、花色苷含量(矢车菊素-3-O-葡萄糖苷2.27 mg/g、矢车菊素-3-O-芸香糖苷0.69 mg/g、天竺葵素-3-葡萄糖苷0.047 mg/g)及抗氧化活性((2,2’-联氨-(3-乙基苯并噻唑啉-6-磺酸)二氨盐)自由基清除能力21.87μmol Trolox/g、1,1-二苯基-2-三硝基苯肼自由基清除能力35.70μmol Trolox/g、铁离子还原能力27.85μmol Trolox/g)均显著高于其他4种解冻方法。综合考虑,微波功率500 W解冻优于其他4种解冻方法。     

不同超声频率对温州蜜柑皮总酚和抗氧化能力的影响

对比分析20、60、100kHz 3种超声频率条件下超声参数(超声时间、提取温度、超声能量)对温州蜜柑皮中总酚及抗氧化能力的影响。结果表明：3种超声频率作用下,随着超声时间、提取温度、超声能量的增加,总酚和抗氧化能力呈显著增加趋势,但是总酚和抗氧化能力的最佳超声条件是各不相同的。此外,60kHz的超声频率处理得到温州蜜柑皮提取物总酚和抗氧化能力均高于20、100kHz处理。超声处理后提取物中总酚和抗氧化性呈现出良好的相关性。在20、60、100kHz 3种频率作用下,15℃超声处理后,相关系数R2依次为0.8228、0.8354、0.8435;在30℃时,R2依次为0.7706、0.8735、0.8895;在40℃时,R2依次为0.8626、0.9248、0.8622;在3.2、8、30、56W的超声能量水平下,R2依次为0.9143、0.9958、0.7971,表明在低频超声范围内超声波技术能有效地增强温州蜜柑皮提取物的抗氧化性。     

Characterization of Red Raspberry (Rubus idaeus L.) Genotypes for Their Physicochemical Properties

ABSTRACT:  The worldwide tendency for growing more small fruits, including raspberries, shows permanent increase because this group of fruits has a relatively higher content of bioactive nutrients. To study the health benefits of red raspberry fruits, 11 preselected wild-grown and 1 well-known cultivar, Heritage, were evaluated for some of their physicochemical properties such as fruit weight, total antioxidant capacity (measured by β-carotene bleaching and FRAP assays), total phenolics, ascorbic acid, soluble solid content (SSC), and acidity. Fruit weight, SSC, and ascorbic acid contents were between 1.47 and 2.32 g, 10.87% and 13.60%, and 21 and 36 mg/100 g, respectively. Antioxidant activity and total phenolic content varied among genotypes and the ERZ5 genotype had the highest antioxidant capacity as ascertained by both methods. This genotype also had the highest total phenolic (2031 μg GAE/g FW) content. There are linear relationships between antioxidant capacities and total phenols. The present study demonstrates the potential of certain wild genotypes, notably ERZ5, for improving the nutritional value through germplasm enhancement programs.     

草莓、黑莓、蓝莓中多酚类物质及其抗氧化活性研究

研究草莓、黑莓、蓝莓3种小浆果的总酚、总黄酮、原花青素含量及其总抗氧化能力。结果表明:蓝莓全果的总酚、总黄酮、原花青素含量在所测3种浆果全果中最高,分别为9.44mg没食子酸/g干质量、36.08mg芦丁/g干质量、24.38mg儿茶素/g干质量;其总抗氧化能力也最强,达14.98mmol Trolox/100g干质量。草莓的总酚、总黄酮、原花青素含量则最低,抗氧化能力也最弱。此外,3种浆果果渣中的总酚、总黄酮、原花青素含量以及总抗氧化能力均高于全果和果汁,即果渣>全果>果汁。总酚含量、总黄酮含量以及原花青素含量与总抗氧化能力之间的相关性分析表明,总酚含量与总抗氧化能力之间存在显著线性相关,相关系数r达到0.9704,表明酚类物质是其抗氧化作用的主要物质基础。     

Development of Active Films From Pectin and Fruit Extracts: Light Protection,Antioxidant Capacity,and Compounds Stability

Pectin films containing fruit extracts were developed and tested in relation to ultraviolet light transmission, phytochemical contents, and antioxidant capacity during 90 d shelf life storage. Aqueous and alcoholic extracts from 5 different fruits (acerola, cashew apple, papaya, pequi, and strawberry) were obtained. Because the alcoholic extracts from acerola, cashew apple, and strawberry presented the highest phytochemical content and antioxidant capacity, they were incorporated into pectin films individually or as a mixture. Incorporation of these extracts into pectin films provided antioxidant capacity while retaining the physical properties. The pectin films containing fruit extract acted as adequate light barrier and prevented photooxidation. Among the prepared films, the pectin film containing acerola extract afforded the highest antioxidant capacity, with a half‐life of 99 d. Overall, the results revealed that incorporation of fruit extracts into pectin films potentially produces antioxidant films and coatings for different food applications.