2株具有优良体外抗氧化能力乳酸菌的筛选与鉴定

已有研究表明乳酸菌可能具有缓解不同因素导致氧化应激的潜力.本研究利用体外过氧化氢氧化胁迫模型筛选出一些具有显著体外抗氧化能力的乳酸菌,以还原活性高低、抑制脂质过氧化能力、DPPH自由基和羟自由基清除能力、亚铁离子和铜离子螯合性能等体外抗氧化能力评价指标评价了乳酸菌分离物的体外抗氧化性能,并最终确定了2株具有优良体外抗氧化能力的乳酸菌CCFM8661和CCFM1566.结果表明,CCFM8661和CCFM1566还原力分别达到(226.47±4.68)、(212.35±6.45) μmol/L半胱氨酸当量;对脂质过氧化的IC50值分别达到8.1、8.3 Log10(CFU/mL);对DPPH自由基和羟基自由基清除率均在60％以上,并具有较高的亚铁离子及铜离子螯合能力.经生理生化鉴定和16SrDNA分子鉴定,该2株菌为植物乳杆菌CCFM8661和干酪乳杆菌CCFM1566.     

乳酸菌抗氧化活性的研究进展

介绍了乳酸菌的抗氧化活性、可能机制及其研究进展。在体外实验中，乳酸菌及其无细胞提取物能清除机体羟自由基(HO)、过氧化氢(H2O2)、二苯代苦味肼基自由基(DPPH)；可抑制脂质过氧化、螯合金属离子，具有总还原能力及SOD酶活性。并介绍了乳酸菌抗氧化活性的体内实验结果。     

几种体外评价乳酸菌无细胞提取物抗氧化活性方法的比较研究

乳酸菌的抗氧化活性与其对人体的健康促进作用密切相关。本研究以DPPH自由基清除能力、羟自由基清除能力、还原活性等为体外抗氧化能力评价指标,对17株不同来源乳酸菌的无细胞提取物抗氧化能力进行评价,并对评价结果进行了比较和筛选,然后进一步研究了抗氧化活性强和低的菌株的抗氧化酶活性。结果显示不同来源乳酸菌的无细胞提取物抗氧化活性存在种间和种内差异,而3种体外化学方法具有显著相关性(p0.01)。3种评价指标均显示嗜酸乳杆菌CCFM8具有很强的抗氧化活性,发酵乳杆菌CCFM381抗氧化活性最弱。进一步乳酸菌无细胞提取物抗氧化酶活性的测定结果也与上述3种体外抗氧化能力评价指标的综合结果具有很好的一致性。该研究为综合评价乳酸菌抗氧化能力以及体外筛选具有高抗氧化活性的乳酸菌提供了可靠的参考依据。     

茄子皮红色素抗氧化活性研究

目的:研究茄子皮天然红色素体外抗氧化活性;方法:以抗坏血酸为对照,以Fenton反应产生羟自由基(·OH),肾上腺素自氧化反应产生超氧阴离子自由基(O-2·)为试验模型,采用紫外分光光度法和荧光分析法,测定茄子皮红色素对羟自由基、超氧阴离子自由基、过氧化氢的清除作用;结果:茄子皮红色素对上述自由基均有清除作用,时羟自由基和超氧阴离子自由基清除效果比抗坏血酸好,清除过氧化氢能力弱于抗坏血酸;结论:茄子皮红色素具有明显清除自由基的作用.     

具抗氧化活性乳酸菌的筛选

以体外过氧化氢耐受能力为指标,从发酵食品中筛选出2株能够耐受1mmol/L浓度过氧化氢的乳酸菌,两株细菌的耐过氧化氢能力与L. rhamnosusGG的耐过氧化氢能力相当。研究了两株乳酸菌完整细胞和无细胞提取物的DPPH自由基和羟自由基清除能力。结果表明,菌体浓度为109mL-1的L1001完整细胞和无细胞提取物的DPPH自由基清除率分别为36.2%和37.9%,同样浓度的F12完整细胞和无细胞提取物对DPPH自由基的清除率分别为24.4%和27.0%;清除羟自由基实验表明,细胞浓度为109mL-1的细胞清除羟自由基能力与同体积的浓度为1mmol/L抗坏血酸相当,L1001的羟自由基清除能力优于F12。利用API鉴定系统L1001菌株被鉴定为植物乳杆菌Lactobacillus plantarum L1001。     

4 种乳酸菌体外抗氧化能力的比较研究

通过抗脂质过氧化、清除DPPH自由基、清除超氧阴离子自由基(O2－ ·)、还原力、清除羟自由基实验对发酵乳杆菌、乳酸乳球菌、嗜酸乳杆菌和瑞士乳杆菌4种乳酸菌发酵上清液和胞内提取物的抗氧化能力进行研究。结果表明：4种乳酸菌的具有不同的抗氧化能力,其中瑞士乳杆菌的羟自由基清除能力、DPPH自由基清除能力和还原能力相对较高,乳酸乳球菌和嗜酸乳杆菌清除O2－ ·能力相对较强,发酵乳杆菌抗脂质过氧化能力为最强。实验还初步研究乳酸菌的抗氧化机理,显示乳酸菌存在SOD和GSH-Px,这可能与乳酸菌的抗氧化作用有一定相关性。     

褐藻多糖的体外抗氧化活性及其延长秀丽隐杆线虫的寿命

该研究探讨了褐藻多糖(FSP)的体外抗氧化作用.以秀丽隐杆线虫为模式动物,采用氧化剂H2O2建立急性氧化应激模型,测定FSP对线虫寿命、运动能力、年龄色素及氧化应激指标的影响.研究表明,FSP对羟基自由基有一定的清除能力,且作用效果呈剂量依赖性;FSP(50、100、200μg/mL)呈剂量依赖性的延长秀丽隐杆线虫寿命...     

发酵祛湿汤体外抗氧化活性及对秀丽隐杆线虫抗衰老作用

利用自由基清除能力评价发酵祛湿汤（Fermented Qushi Decoction,FQD）的体外抗氧化活性;结果显示,与未发酵祛湿汤（Qushi Decoction,QD）相比,高剂量FQD组的总抗氧化能力显著提高,其中1,1-二苯基-2-三硝基苯肼自由基清除率、羟自由基清除率和总还原能力分别提高了24.38%、11.98%、11.76%。FQD对线虫总产卵量无显著影响,并能促进线虫的运动;与QD相比,FQD干预后线虫平均寿命延长了8.02%～26.36%;在热应激条件下,FQD组最长存活时间提高了25%,在氧化应激下,FQD组线虫的生存时间较QD提高了16.67%。此外,FQD作用后,线虫体内抗氧化酶活性显著增强（P<0.05）,脂褐质的堆积水平降低。综上,FQD通过提高体外抗氧化能力,延长线虫寿命,提升抵抗应激能力和抗氧化酶活性来延缓线虫的抗衰老作用。该研究初步表明发酵祛湿汤具有抗衰老作用,为保健品开发和利用提供理论基础。     

不同乳酸菌菌株抗氧化能力的比较研究

目的：比较不同乳酸菌菌株的抗氧化能力,为其天然抗氧化剂的开发提供理论依据。方法：通过羟自由基清除实验,超氧阴离子自由基清除实验,DPPH 自由基清除实验以及还原能力测定实验,对35 株乳酸菌的菌体、无细胞提取物以及胞外分泌物的抗氧化能力进行研究。结果：比较发现La 5 和La 29 两株乳酸菌抗氧化能力相对较高。结论：不同来源的乳酸菌菌株还原能力不同,且在羟自由基、超氧阴离子自由基和DPPH 自由基的清除能力方面存在差异;且其发挥抗氧化作用的活性物质存在的部位也因菌株的不同而具有较大的差异性。     

艾叶总黄酮提取物体内外抗氧化活性研究

本文探究了艾叶总黄酮提取物（total flavonoids extract from folium of Artemisia argyi,TFEFAA）主要成分含量及其体内外抗氧化活性。本文采用高效液相色谱（HPLC）法同时检测TFEFAA中异泽兰黄素和棕矢车菊素的含量;以1,1-二苯基-2-三硝基苯肼（DPPH）、2,2-联氮-二（3-乙基-苯并噻唑-6-磺酸）二铵盐（ABTS）和羟自由基三种自由基的清除率和总还原力为指标,考察TFEFAA的体外抗氧化活性;将秀丽隐杆线虫（线虫）同期化后分别培养在含有0、50、100 μg/mL的TFEFAA的线虫生长培养基中,研究TFEFAA对线虫热应激和H₂O₂氧化应激的影响,同时检测线虫体内相关抗氧化酶活力和丙二醛（MDA）的含量。结果表明,异泽兰黄素和棕矢车菊素的含量分别为0.2%和0.06%;TFEFAA对DPPH自由基、ABTS+自由基和羟自由基均具有显著的清除作用（P<0.05）,其半数清除浓度（IC₅₀）分别为96.51、67.73和279.38 μg/mL,清除能力与TFEFAA均呈剂量-效应关系,同时还具有较强的总还原力;100 μg/mL TFEFAA能极显著延长线虫在热应激和H₂O₂氧化应激条件下的存活时间（P<0.01）,同时极显著提高线虫体内超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GSH-Px）的活力（P<0.01）,并且显著降低线虫体内MDA含量（P<0.05）。TFEFAA在体内外均具有较好的抗氧化活性,其机制可能与提高体内抗氧化酶活性有关。因此,TFEFAA有望被开发成新型天然绿色食品抗氧化剂。     

酚胺类抗氧化剂复配对生物柴油抗氧化性能影响研究

采用Rancimat法研究3种酚类抗氧化剂丁羟基茴香醚(BHA)、叔丁基对苯二酚(TBHQ)、没食子酸丙酯(PG)与3种胺类抗氧化剂四乙烯五胺(TEPA)、邻苯二胺(OPD)、二烷基二苯胺(ADPA)及其复配对菜籽油生物柴油诱导期的影响,并对其复配后协同抗氧化机理进行了分析。结果表明:菜籽油生物柴油的诱导期为2.03 h,达不到国家标准(6 h);6种抗氧化剂在添加量为0.4%时,抗氧化效果强弱顺序为TBHQTEPAPGBHAOPDADPA;酚类抗氧化剂与TEPA复配的抗氧化效果增加最明显,其次是酚类抗氧化剂与OPD复配,而ADPA与酚类抗氧化剂复配效果最差。     

天然抗氧化剂对鳄鱼油体外抗氧化活性的影响

为了筛选天然抗氧化剂和提高鳄鱼油体外抗氧化活性,采用Schaal烘箱法,比较3种常见的天然抗氧化剂茶多酚（TP)、维生素E和植酸对精制鳄鱼油的抗氧化效果,并优选出了天然抗氧化剂。在此基础上以优选抗氧化剂和VC为阳性对照,采用体外抗氧化法考察添加优选抗氧化剂的鳄鱼油对DPPH自由基、羟自由基（·OH）、超氧自由基（O-2·）清除能力,还原能力及Fe2+螯合能力。结果表明：3种天然抗氧化剂对鳄鱼油的抗氧化效果为TP＞维生素E＞植酸;鳄鱼油对DPPH自由基、·OH、O-2·清除能力,还原能力和Fe2+螯合能力均随其质量浓度的增加而升高;添加0.02%TP后鳄鱼油的体外抗氧化活性明显增强,添加TP的鳄鱼油对DPPH自由基、·OH和O-2·的IC50分别为0.874、0.064 mg/mL和0.96 mg/mL,均低于鳄鱼油的（5.448、0.684、4.53 mg/mL）,而还原能力和Fe2+螯合能力均高于鳄鱼油的。综上,TP可有效提高鳄鱼油的体外抗氧化活性。     

Determination of antioxidant compounds and antioxidant activity in commercial oilseeds for food use

Different commercial edible oilseed samples were analyzed in order to evaluate the compounds involved in antioxidant activity. Fatty acids, triacylglycerols, tocopherols, chlorophylls, β-carotene, squalene, phenolic compounds and CIE L^∗a^∗b^∗ coordinates were assayed. Strong chemical variability depending on the oilseed variety was observed. Antioxidant activity was evaluated for the oils, both for their methanol-soluble phase and the fraction insoluble in methanol. DPPH radical scavenging activity expressed in TEAC ranged between 0.45 and 2.30 mmol/l in peanut and maize oils, respectively. Free radical scavenging activity was mainly influenced by tocopherols content (r = +0.70) in oils and polyunsaturated fatty acids (r = +0.61) in the fraction nonsoluble in methanol. Variability of the correlation between the antioxidant activity and the composition of the oilseeds could be attributed to the differences in the squalene, chlorophylls, carotenoids, and phenols contents of the oils and their mutual interactions.     

Secondary structures and their effects on antioxidant capacity of antioxidant peptides in yogurt

The pH, thermal, urea, and trifluoroethanol treatments were used to denature yogurt antioxidant peptides, and their antioxidant capacities and secondary structures were analysed. Results showed that yogurt peptides treated at pH 6.0 or above 50°C exhibited higher antioxidant activity than the control, whereas trifluoroethanol treatment resulted in a reduction and urea treatment held invariability. Peptide secondary configuration analyses revealed that these treated peptides significantly decreased their α-helical conformation but enhanced the β-sheet presence as well as an obvious alteration on β-turn and random coil structures. These peptide conformation alterations contributed to their antioxidant property increase.     

减压贮藏对番茄果实抗氧化物质和抗氧化酶的影响

为了研究不同减压处理对番茄果实后熟过程中抗氧化性的影响,以粉冠番茄为材料,研究了在43.6、73.0kPa和常压三个压力条件下,番茄中维生素C、番茄红素和谷胱甘肽含量,以及超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性变化规律.结果表明,减压贮藏显著推迟了番茄中维生素C含量的高峰,在一定程度上延迟了番茄红素和谷胱甘肽含量的高峰,并且压力越低效果越显著(p＜0.05);在果实后熟过程中SOD、CAT活性逐渐下降,而减压处理可显著抑制SOD活性下降(p＜0.05).POD活性在贮藏期间呈现先降后升的趋势,减压处理可以有效地保持较高的抗氧化酶活性.结论:减压处理贮藏可以显著保护番茄果实中的抗氧化物质和抗氧化酶活性,而且一定范围内压力越低效果越好.     

不同处理工艺对玫瑰花中抗氧化物质含量及抗氧化活性的影响

目的 研究不同处理工艺对平阴玫瑰中总黄酮、芦丁、总多酚含量及抗氧化活性的影响。方法 对干花直接提取、干花超微粉碎提取以及鲜花冷冻干燥提取3种不同处理工艺的平阴玫瑰进行水提,采用分光光度法测定水提液中总黄酮、总多酚的含量,高效液相色谱法测定水提液中芦丁含量,并对3种不同处理工艺的水提液进行1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl, DPPH)自由基清除、羟自由基清除以及超氧阴离子清除能力的研究。结果 3种不同工艺处理的玫瑰花总黄酮含量、芦丁含量、总多酚含量及抗氧化活性均为：鲜花冷冻干燥>干花超微粉碎>干花直接提取。结论 经冷冻干燥处理后的平阴玫瑰抗氧化性物质含量及抗氧化活性均有升高,为玫瑰花抗氧化应用提供依据。     

Analysis of antioxidant activity and antioxidant constituents of Chinese toon

Antioxidant activity of the methanol and water extracts of Chinese toon (Toona sinensis) leaf was evaluated using DPPH radical scavenging and lipid peroxidation assays. Contents of four major types of antioxidants including β-carotene, ascorbate, α-tocopherol and phenolics were also quantified. Open column chromatography followed by semi-preparative HPLC were applied to separate phenolic antioxidants whose contents were subsequently determined by HPLC. The methanol extract demonstrated much higher antioxidant activity than the water extract. Contents of β-carotene, ascorbate, α-tocopherol and phenolics were 1.23 μmol g^?1, 34.2 μmol g^?1, 2.40 μmol g^?1 and 872 μmol gallic acid equivalents g^?1, respectively. Six phenols were isolated. Their structures were characterized as 5-O-galloylquinic acid, gallic acid, methyl gallate, β-1,2,6-tri-O-galloyl-d-glucose, quercetin 3-O-β-d-glucopyranoside and quercetin 3-O-(2′′-O-galloyl)-β-d-glucopyranoside, respectively. The results indicate that phenolic compounds are the dominant antioxidants in Chinese toon. The compounds β-1,2,6-tri-O-galloyl-d-glucose and quercetin 3-O-(2′′-O-galloyl)-β-d-glucopyranoside were reported for the first time in Chinese toon.     

天然抗氧化剂对辣椒鸡油抗氧化性能的影响

为了筛选出适合辣椒鸡油的天然抗氧化剂,以延长其保质期,研究并比较了6种天然抗氧化剂（迷迭香提取物、维生素E、茶多酚、维生素C、槲皮素和硫辛酸）对辣椒鸡油酸值、过氧化值、DPPH自由基清除能力和总还原能力的影响。结果表明：6种天然抗氧化剂在辣椒鸡油中均具有一定的抗氧化能力;在抑制酸值方面,槲皮素效果最佳,维生素C最差;在抑制过氧化值方面,槲皮素效果最佳,维生素E最差;在DPPH自由基清除能力方面,迷迭香提取物效果最佳,硫辛酸最差;在总还原能力方面,槲皮素效果最佳,维生素E最差;槲皮素、迷迭香提取物和茶多酚在酸值、过氧化值、DPPH自由基清除能力和总还原能力方面均位于前三。综合考虑抗氧化效果、抗氧化剂稳定性、成本等因素,可优先选择迷迭香提取物和茶多酚作为辣椒鸡油的抗氧化剂以提高其储藏性能。     

Evaluation of spectrophotometric methods for antioxidant compound measurement in relation to total antioxidant capacity in beverages

The validity of different colorimetric methods used to quantify various families of antioxidant compounds was evaluated with standard compounds. The colorimetric tests for global evaluation of flavonoids, anthocyans, and flavanols were found generally unreliable, as reactions could be different for individual compounds within a family (anthocyanins or flavonols or flavan-3-ols) and not specific to one family. In the flavonoid test, for example, flavonols reacted very well, anthocyanins did not react, and flavanons reacted only slightly. The same methods were applied also to beverages known for their antioxidant content (apple, orange, grape, and vegetable juices, ice tea, and red wine) and the data were compared with the results of HPLC analysis of specific compounds. The values obtained in a colorimetric test were generally higher than the sum of the values obtained for the corresponding individual compounds by HPLC analysis, mainly because other compounds can interfere with the colorimetric tests. For example, in wine, anthocyanin concentrations obtained by colorimetric test were 9068 ± 1407 μmol/100 ml (mean ± SEM), higher than the sum of the six main anthocyanidins detected by HPLC, only 41 μmol/100 ml. The relative antioxidant capacity values determined for beverages on the basis of colorimetric tests could exceed by far the values previously measured in radical-scavenging tests (for instance, the antioxidant capacity attributable to anthocyans in wine on the basis of the colorimetric test was 50 times higher than the total antioxidant capacity measured by the ORAC assay). In conclusion, colorimetric tests for flavonoids, anthocyans, and flavanols appeared generally unreliable for estimating their content and thus the antioxidant capacity reliable to these compounds.