糖类对羊血超氧化物歧化酶活性的影响

目的：研究糖类对羊血超氧化物歧化酶(SOD)活性影响关系。方法：以离子交换层析法制备的羊血SOD为原料,加入不同浓度的麦芽糖、蔗糖、乳糖、海藻糖、D-葡萄糖、D-果糖、D-木糖和D-甘露糖,25℃分别保温4、24、48、72h和96h后,利用邻苯三酚自氧化法测定SOD酶活力,并计算相对酶活力。结果：海藻糖对羊血SOD有明显的激活和保护作用,高浓度的麦芽糖和低浓度的乳糖有一定稳定作用,其余糖类对SOD活性影响不大。结论：不同糖类在不同浓度下对羊血SOD活性影响不同。     

Application of Freezing and Thawing in Apple (Malus domestica) Juice Extraction

The paper presents the results of the research on the impact of enzymatic liquefaction, freezing and thawing on the efficiency of juice pressure extraction from apple pulp and quality of the obtained juices. The research was conducted using three types of pretreatment prior the pressing: crushing and enzymatic liquefaction in temperature of 25 °C, crushing and enzymatic liquefaction in temperature of 45 °C and crushing followed by freezing and thawing of the pulp. The study included three varieties of apples. The juice was obtained using a laboratory basket press. It was determined that the pretreatment of the pulp as well as the varietal characteristics of the fruits have a significant impact on the efficiency of the pressure extraction process. The enzymatic treatment of the pulp, irrespective of the temperature at which it was conducted, significantly increased the efficiency of the process. No effect of the temperature (25 or 45 °C) of enzymatic treatment on the efficiency of the pressure extraction process was found. Pretreatment of the pulp based on freezing and thawing contributes to the increase of efficiency of pressing in the case of two apple cultivars, that is, Idared and Red Delicious. It was showed that total phenolic content, antioxidant activity, the soluble solids content and juice acidity (pH) depend on the pretreatment of the pulp and the varietal characteristics of apples. Following the application of pretreatment of the pulp, an increase was observed in the content of polyphenols and in the antioxidant activity of the juices obtained.     

Fruit quality of ‘Fuji’ apple (Malus domestica Borkh.) strains

‘Fuji’ is an attractive apple for consumers owing to its desirable internal (low acidity, high sugar and phenols) and external (firmness, colouration) fruit quality. However, its red colouration is often weak and starts late in the season. Therefore, in 2003 and 2004, three ‘Fuji’ strains, ‘Kiku 7’, Kiku 8' and ‘Naga‐fu 6’, and standard ‘Fuji’ were compared in terms of fruit quality by high‐performance liquid chromatography analysis in order to determine their contents of fruit sugar, organic acids and phenols. The % and intensity of red top colour were also analysed. Of the three strains, ‘Kiku 8’ proved to have the best red colouration and accumulated the largest amount of reducing sugars with the lowest quantity of phenols in both years examined. The quality parameters of strains ‘Kiku 7’ and ‘Naga‐fu 6’ fell between those of standard ‘Fuji’ and ‘Kiku 8’. ‘Kiku 8’ may be the most suitable for areas with high variations in daily and nightly temperatures to obtain the best colour development. Under conditions with warm days and cool nights the other strains and standard ‘Fuji’ can develop a proper coloured fruit of high quality. Copyright © 2007 Society of Chemical Industry     

超氧化物歧化酶在啤酒酿造方面的研究

本文综述了氧自由基对啤酒酿造过程的危害以及风味的老化机制,揭示了超氧化物歧化酶（SOD）在啤酒酿造过程中的有益作用,比较了其他抗氧化剂（二氧化硫、抗坏血酸、葡萄糖氧化酶等）的特点,并提出了利用SOD和过氧化氢酶（CAT）的协同作用阻断OH·的形成路线,以进一步改善啤酒风味稳定性的新思路。     

红酵母提取SOD的研究

研究了从红酵母中提取、纯化超氧化物歧化酶(SOD)的方法和条件。所得SOD酶比活2297．20U/mg，对粗酶液的收率为89．94％，纯化倍数为11倍。     

纳豆中SOD的分离纯化及性质的研究

通过采用不同的溶液、pH和温度处理探讨了对SOD提取物活性的影响,采用硫酸铵沉淀法粗提,葡聚糖凝胶过柱,利用聚丙烯酰胺凝胶电泳法判定纯度.结果表明,提取时纳豆捣碎与否结果没有差异,采用缓冲液效果较好.采用50℃以上的温度处理影响酶活性,硫酸铵饱和度在65％～90％时得到较纯的酶粗提物,pH5.9的条件下有利于分离纯化,得到了分子量为3.86×104u的Fe-SOD型SOD.     

显微高光谱技术检测肌细胞中超氧化物歧化酶活力的方法研究

利用可见显微高光谱技术对羊肉肌细胞中的超氧化物歧化酶(Superoxide dismutase,SOD)活力进行检测。通过显微高光谱系统(380~980 nm)采集223个显微图像,根据样本光谱的反射率提取感兴趣区域并结合SOD酶活力建立模型。对原始光谱结合偏最小二乘回归模型,进行样本集划分及多种光谱预处理的模型对比分析,优选出多元散射校正为预处理方法,采用6种方法提取特征波长,并根据特征波长建立偏最小二乘回归、多元线性回归、主成分回归三种模型。结果显示,建立基于竞争性自适应重加权法挑选特征波长的多元线性回归模型最优,预测集的相关系数和均方根误差分别为0.8351和21.3578 U/mg·prot。采用显微高光谱成像技术对肌细胞内超氧化物歧化酶活力的检测是具有可行性的。     

利用低温聚合酶链式反应技术提高大豆超氧化物歧化酶活性

目的：利用低温聚合酶链式反应对大豆超氧化物歧化酶（superoxide dismutase,SOD）的活性进行改良。方法：将6 种在较低退火温度下扩增出的超氧化物歧化酶基因插入到表达载体pREP5N上,构建pPM1、pPM2、pPM3、pPM4、pPM5、pPM6表达载体,转入大肠杆菌后得到工程菌,诱导其在大肠杆菌中进行蛋白表达,并进行酶活力测定,筛选高酶活力菌株。结果：将已克隆的目的基因序列与已知的大豆MnSOD基因序列比对分析,一致性平均为86.57%,氨基酸序列同源性平均为82.58%。对已获得的6 种工程菌进行蛋白质提取,十二烷基硫酸钠-聚丙烯酰胺凝胶电泳结果显示表达产物的分子质量约为26 kD。经1%差异水平分析,改良后的SOD酶活力均有极显著提高,平均比对照菌株的酶活力提高1.95 倍。结论：本实验证明低温聚合酶链式反应是改变酶活性的一种有效方法,为超氧化物歧化酶在生产中的应用提供了技术支持。     

Influence of rootstock on drought response in young 'Gale Gala' apple (Malus domestica Borkh.) trees

BACKGROUND: Drought is a major environmental stress limiting plant growth, productivity, and survival worldwide. Rootstocks are widely used to enhance plants resistance to drought stresses. This study determined influence of rootstock on drought responses in 1‐year‐old ‘Gale Gala’ apple trees grafted onto Malus sieversii or M. hupehensis. RESULTS: Choice of rootstock resulted in differential response to drought stress. Specifically, M. sieversii caused less drought‐induced reduction in relative growth rate, biomass accumulation, leaf area, leaf chlorophyll content, relative water content, photosynthesis rate and maximum chlorophyll fluorescence yield but greater increase in whole‐plant water use efficiency compared to M. hupehensis. Secondly, compared with M. hupehensis, M. sieversii caused less drought‐induced accumulation of reactive oxygen species but more increase in activities of antioxidant enzymes. In addition, xylem sap abscisic acid concentration was greater in trees grafted onto M. hupehensis than in those grafted onto M. sieversii under drought stress. CONCLUSION: ‘Gale Gala’ trees' response to drought stress was associated with the rootstock's genotype onto which it was grafted. Trees with M. sieversii as rootstock are more drought resistant than trees with M. hupehensis as rootstock, which suggests that M. sieversii can be widely used as rootstock in arid and semi‐arid regions. Copyright © 2012 Society of Chemical Industry     

玉米胚芽超氧化物歧化酶提取及对酒精发酵的影响

从玉米胚芽提取SOD的最佳工艺条件为：100g玉米中加入200mL0．05mol/L磷酸缓冲液，40℃浸泡玉米36h，淋干后分离胚芽与胚乳，再加入胚芽质量2倍的0．05mol/L磷酸缓冲液破碎后浸提1h，离心得SOD提取液，总酶活为22549．0u；然后添加硫酸铵依次达到饱和度40％和90％，进行除杂蛋白和盐析，离心后将沉淀冷冻干燥即得到SOD粗酶制剂，其比活为334．6u／mg蛋白。将分离后的胚乳和提取SOD后的胚芽残渣混合进行酒精发酵，淀粉出酒率达到53．16％，证明胚芽SOD提取不影响酒精发酵，且可降低酒精的生产成本。     

Polyphenol Oxidase from Apple (Malus domestica Borkh. cv Bramley's Seedling): Purification Strategies and Characterization

ABSTRACT Polyphenol oxidase (PPO) was isolated from Bramley's Seedling apples with 75.7‐fold purification and 26.5% recovery by ammonium sulfate precipitation, phenyl sepharose chromatography, ion exchange chromatography, and hydroxyapatite chromatography. Molecular weight was estimated to be about 45 kDa by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS PAGE). Optimum PPO activity was at pH 6.5 and greater than 50% activity was retained during storage for 72 h at pH 5.5 to 6.5. Optimum temperature for activity was 30 °C and the enzyme had residual activity of greater than 50% during storage for 72 h at 20 °C to 30 °C and for 24 h at 40 °C to 50 °C. Of the substrates tested, activity was greatest with 4‐methylcatechol followed by catechol, pyrogallol, and (?)epicatechin. The most effective inhibitors tested were sodium metabisulfite and ascorbic acid.     

蜂王浆中超氧化物歧化酶的活性测定与应用

为评价蜂王浆的质量与新鲜度,该文采用黄嘌呤氧化酶法测定蜂王浆中的超氧化物歧化酶(superoxide dismutase,SOD)活性,优化蜂王浆的预处理方法,比较不同贮存时间和温度条件下蜂王浆中SOD活性的变化及不同生产工艺和蜜源的蜂王浆产品中SOD的活性.优化的预处理方法为蜂王浆样品稀释溶解于生理盐水中至3倍体积,...     

山葡萄籽和皮中原花青素类SOD活性的测定

采用邻苯三酚自氧化法测定山葡萄籽和皮中原花青素SOD-L的活性为192.85U/g和78.45U/g。通过实验确定了适宜的测定条件：测定波长325nm,缓冲体系为 Tris-HAc缓冲液,浓度为50mmol,pH8.2。原花色素SOD-L对连苯三酚自氧化的抑制率达到91%。     

Impact of shelf life on content of primary and secondary metabolites in apple (Malus domestica Borkh.)

In this study, we evaluated the changes in apple fruit quality during shelf life. After a month of cold storage, apples of cultivars "Jonagold" and "Golden Delicious" were exposed to ambient temperatures for 21 d, with subsequent sampling every 3 or 4 d. Fruit firmness, changes in amounts of sugars, malic acid, and phenolics were observed during shelf life. Chemical analyses were done with HPLC-PDA system. An interchange between various sugars was noticed, but in general, the sum of sugars remained at the same level. The content of malic acid remained stable or dropped, resulting in sweeter fruit. Levels of phenolics were more constant in the pulp of both cultivars analyzed, while in the peel, the changes were more pronounced. In the pulp, a peak in the content of hydroxycinnamic acids and flavanols was noticed on the 2nd or 3rd sampling and afterwards, the amounts remained constant. In the peel an initial decrease of all analyzed phenolic groups was observed in both cultivars, however it was more pronounced in "Jonagold." It can be concluded that changes in primary and secondary metabolites are not the main reason for the lower quality of fruit exposed to ambient temperatures. On the other hand, fruit firmness might be the limiting factor for shelf life duration.     

大豆锰超氧化物歧化酶基因在乳酸乳球菌中的分泌表达

为使大豆锰超氧化物歧化酶（Mn superoxide dismutase,MnSOD）在乳酸乳球菌中高效表达,将克隆的MnSOD基因开放阅读框序列分别重组到质粒pNZ8149和经改造的质粒pNZS上,表达载体pNZ-SOD和分泌表达载体pNZS-SOD,将两者分别以电穿孔法转化乳酸乳球菌L. lactis NZ3900,经Elliker琼脂板筛选、聚合酶链式反应（polymerase chain reaction,PCR）、酶切鉴定正确后,获得的两重组菌株加入Nisin进行诱导表达,对L. lactisNZ3900/pNZ-SOD和L. lactis NZ3900/pNZS-SOD的表达产物进行十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（sodiumdodecyl sulfate - polyacrylamide gel electrophoresis,SDS-PAGE）和酶活性对比分析。结果显示：L. lactis NZ3900/pNZS-SOD菌株表达SOD总活性约是L. lactis NZ3900/pNZ-SOD菌株的1.6 倍,是L. lactis NZ3900/pNZ8149的13.5倍,且可将表达的约2/3的SOD分泌到胞外,表明经改造的乳酸菌分泌表达系统L. lactis NZ3900/pNZS能够分泌表达SOD,并增强SOD的表达。     

柑橘主要组织SOD分布及其在生长中晚期活性变化

以16个柑橘品种为材料,通过测定叶片、果皮、果肉和种子4种组织中超氧化物歧化酶(SOD)的活性大小,研究柑橘SOD的分布情况,以及在柑橘生长过程中SOD活性的变化趋势。结果表明:柑橘果皮、果肉、种子和叶片4种组织中均存在SOD,其活性大小依次为:叶片>种子>果皮>果肉;柑橘各个组织之间SOD活性呈显著性差异,个别品种的相同组织之间SOD的活性也呈显著差异。在柑橘生长中后期,随着果实的逐渐成熟其果皮和果肉组织中SOD的活性变化呈现多样化趋势,但活性变化幅度较小;在种子和叶片组织中SOD的活性变化呈持续上升趋势。     

牛血铜锌超氧化物歧化酶分离提取新工艺

在传统制备超氧化物歧化酶的基础上,进行工艺改进。直接用血块,采用机械破碎法破膜,热变性及两次乙醇-氯仿沉淀除杂蛋白,然后丙酮沉淀,按照此工艺分离提取获得高纯度的Cu,Zn-SOD,比活达到6988U/mg•pro。     

黄棒菜超氧化物歧化酶(SOD)分离纯化的技术

以植物新品种黄棒菜为原料,研究料液比,浸提温度及pH,热变性温度及时间、丙酮加入量等因素对黄棒菜超氧化物歧化酶(SOD)提取效果的影响,利用正交试验与单因素试验优化提取工艺。结果表明,提取SOD的最佳条件为:料液比1︰3(g/mL),浸提温度0℃,pH 7.0,50℃热变性20 min,1.5倍酶液体积的丙酮,此时SOD纯化倍数可达3.17。经层析纯化及真空冷冻干燥,获得SOD成品。最佳条件下处理新鲜黄棒菜叶茎、叶片组织,测得SOD最终比活力分别为7662.23 U/mg,4897.39 U/mg,纯化倍数达17.55、23.08,叶茎更适于提取SOD。经电泳检测,黄棒菜SOD相对分子质量约80 kDa,据文献鉴定为Mn-SOD。试验结果为黄棒菜SOD的分离纯化及资源开发提供技术参考。