高抗氧化活性肉用乳杆菌的筛选鉴定及其在发酵香肠中的应用

目的 筛选高抗氧化活性肉用乳杆菌,并应用到发酵香肠中。方法 以肉品发酵剂标准、自由基清除率、耐过氧化氢能力和抗氧化酶活性为指标进行菌株筛选,经形态学、生理生化及16S rDNA对菌株进行鉴定,通过硫代巴比妥酸值、羰基和巯基值探究菌株对发酵香肠的抗氧化作用。结果 菌株CC-3符合硝酸盐还原酶阳性、氨基酸脱羧酶阴性等肉用发酵剂标准；该菌株具有较高的自由基清除能力,其发酵上清液DPPH.和OH.清除率分别为98.43%、42.75%,菌体细胞.清除率为75.56%；具有较高的抗氧化酶活性,其细胞破碎液T-SOD活力和CAT活力分别为45.17±0.29、58.50±0.28 U. mgprot_^-1,发酵上清液GSH-Px活力为98.16±0.65 U.mgprot_^-1。菌株CC-3鉴定为植物乳杆菌。接种菌株CC-3的发酵香肠与其他组比较在发酵结束时TBARS值和羰基值最低,分别为0.22±0.01、1.57±0.06 nmol.mg_^-1；巯基值最高,为0.05±0.01 nmol.g_^-1。结论 菌株CC-3符合肉用发酵剂标准且具有高抗氧化活性,可以抑制发酵香肠脂肪氧化和蛋白氧化,具有重要的开发潜力。     

樟树籽油抗氧化能力及物质基础研究

植物油中天然抗氧化成分对油脂的加工、货架期及营养品质具有重要影响。为研究樟树籽油抗氧化活性及物质基础,本文分别对其脂肪酸组成、不皂化物含量、总酚含量和DPPH自由基清除率进行测定,分析总多酚及不皂化物对樟树籽油抗氧化活性的贡献率,明确樟树籽油抗氧化活性物质基础。结果表明,樟树籽油中主要为中链脂肪酸癸酸和月桂酸,二者含量占总脂肪酸的94.80%,不皂化物含量为0.55±0.01% ,总多酚含量为33.07 ±0.63 mg.kg_^-1。樟树籽油对DPPH自由基清除率的IC₅₀值为0.13 g.mL_^-1。相同质量浓度的樟树籽油、不皂化物和总多酚对DPPH自由基清除率分别为98.92±1.58%、38.49±0.66%、49.60±3.78%。因此,不皂化物及总酚对樟树籽油抗氧化贡献率分别为38.91%、50.14%。研究结果表明樟树籽油具有较强的抗氧化能力,其抗氧化活性物质主要为多酚类成分和不皂化物,二者对樟树籽油抗氧化能力的总贡献率高达89.05%。本研究初步明确了樟树籽油的抗氧化活性成分,可为樟树籽油的开发利用奠定基础。     

杨梅提取物抑制二羰基化合物活性研究

目的 分离纯化杨梅果实提取物并考察不同组分对模型及饼干中甲基乙二醛(methylglyoxal, MGO)、乙二醛(glyoxal, GO)的抑制效果。方法 乙醇浸提制备杨梅果实粗提物(crude extract, CE),采用AB-8大孔吸附树脂,以不同体积分数的乙醇(20%、40%、60%)洗脱,得到三种杨梅提取物;采用NaNO₂- Al(NO₃)₃-NaOH比色法、pH示差法、液相色谱-质谱法测定提取物中花色苷、总黄酮含量和主要成分,并用气相色谱法考察其对模型和曲奇中MGO/GO的抑制活性。结果 40%乙醇组分F₁得率最高,活性最好,主要成分为矢车菊素-3-O-葡萄糖苷(cyanidin-3-O-glucoside, C-3-Glu)和杨梅素-3-O-鼠李糖苷(myricetin-3-O-rhamnoside, M-3-Rha);60%乙醇洗脱组分F₂成分主要为槲皮素-3-O-鼠李糖苷(quercetin-3-O-rhamnoside, Q-3-Rha);当曲奇中提取物添加量为0.4%时,F_1、F₂对MGO和GO均有抑制活性,其中F₁效果最佳,分别为61.5%和40.4%。结论 杨梅果实提取物具有良好清除MGO/GO的能力,为其作为添加剂应用于抑制食品加工中的MGO和GO提供了一定的理论基础。     

青叶苎麻叶多酚超声辅助提取工艺优化及抗氧化活性研究

优化了青叶苎麻叶多酚的提取工艺参数,并以没食子酸为对照评价了青叶苎麻叶多酚的抗氧化活性。结果表明:优化出的多酚提取工艺参数分别为料液比(m_苎麻∶V_乙醇) 1∶33 (g/mL)、乙醇体积分数40%、提取温度42 ℃,在此条件下青叶苎麻多酚提取量为47.97 mg/g。青叶苎麻叶多酚清除DPPH自由基和ABTS⁺自由基的IC₅₀值分别为(0.15±0.00),(2.28±0.03) μg/mL,氧自由基吸收能力为(42.41±0.01) g Trolox/g多酚,均明显优于没食子酸,具有良好的抗氧化效果。     

番荔枝单体Bullatacin调节Th1/Th2平衡对小鼠H22肝癌的抑制作用研究

目的研究番荔枝单体Bullatacin对C57BL/6J小鼠接种H22肝癌细胞形成移植瘤的作用及其影响。方法将雌雄各半C57BL/6J小鼠分为空白对照组、模型组、Bullatacin干预组和顺铂对照组,每组10只,每只接种H22细胞数量1×106。Bullatacin浓度100μg·m L^-1,每次0.1 m L腹腔注射,每天1次,连续3天,14天后取材。结果 Bullatacin可抑制移植瘤的生长,其疗效优于顺铂组（P<0.05）。免疫组化结果显示Bullatacin可抑制移植瘤Ki67的表达。C57BL/6J小鼠空白对照组淋巴细胞表达白介素-4（IL-4）的阳性率为（17.3±0.35）%,而在形成移植瘤后为（24.2±0.32）%,Bullatacin干预后为（12.7±0.35）%,顺铂对照组为（11.2±0.33）%。C57BL/6J小鼠空白对照组淋巴细胞γ-干扰素（IFN-γ）的阳性率为（13.4±0.34）%,而在形成移植瘤后为（5.6±0.33）%,顺铂对照组为（6.2±0.35）%,Bullatacin干预后为（14.3±0.33）%。通过淋巴细胞分析表明,移植瘤使Th1/Th2漂移,而Bullatacin可使Th1/Th2向正常转化,顺铂则无此作用。C57BL/6J小鼠的血清IFN-γ含量为（132.2±6.7）pg·m L^-1,接种H22后为（98.9±6.8）pg·m L^-1,使用顺铂后为（77.5±7.0）pg·m L^-1,而在Bullatacin干预后达到（161.5±6.5）pg·m L^-1。C57BL/6J小鼠的血清IL-4为（6.20±1.0）pg·m L^-1,接种H22形成移植瘤后显著升高,达到（16.25±1.1）pg·m L^-1,顺铂干预后为（3.70±1.1）pg·m L^-1,使用Bullatacin干预后为（6.51±1.2）pg·m L^-1,空白组、模型组和Bullatacin干预之间的差异具有统计学意义（P<0.05）。结论番荔枝单体Bullatacin可以有效缩小H22肝癌细胞形成的移植瘤,促进Th1/Th2恢复至平衡状态。     

有色米乳酸饮料发酵工艺优化及抗氧化和降血糖活性研究

目的:开发具有较好抗氧化及降血糖活性的有色米乳酸饮料产品。方法:以黑米和紫米为主要原料,考察有色米比例构成、乳酸菌发酵粉添加量、发酵时间、料液比对有色米乳酸饮料感官评分值、总酚含量、铁离子还原能力、ABTS自由基清除能力、α-葡萄糖苷酶抑制率的影响。结果:有色米乳酸饮料最佳发酵工艺条件为紫米和黑米质量比(m_紫米∶m_黑米)1∶5,料液比1∶8 (g/mL),乳酸菌发酵粉添加量5%,发酵时间40 h,此条件下有色米乳酸饮料感官评分值为83.6±2.51,ABTS自由基清除能力为(145.02±7.88) mmol TE/g·DW,铁离子还原能力(FRAP)为 (33.41±1.70) mmol Fe²⁺/g·DW,总酚含量为(4 208.78±281.26) μg GAE/g·DW,α-葡萄糖苷酶抑制率为(13.94±0.01)%。结论:有色米乳酸饮料呈紫红色,口感柔和,酸甜味适中,具有较好的抗氧化活性和α-葡萄糖苷酶抑制活性。     

基于高倍富集放大反应的双点电位滴定法测定谷物中氟含量

【目的】饮食中氟可影响人体健康与安全,简捷准确检测饮食中氟含量就显得十分重要。【方法】以现有GB/T 5009. 18-2003的氟离子电极电位滴定法为基础,以高倍富集放大反应为获得高灵敏度的突破点,以双点电位滴定法为确保方法准确的手段,探寻出灵敏准确测定谷物中微量氟的新方法。以方法的检测限(LOD)、加标回收率和相对标准偏差(RSD)等为衡量指标,通过单因素试验法对影响富集反应的富集剂种类、用量、温度、时间、反应体系酸度(pH)、搅拌速率和洗涤次数等因素考察后,针对富集反应主要影响因素富集剂用量、反应温度、反应时间和反应体系酸度(pH)等用L₉(3^₄)正交试验优化获得最适宜的测定条件。【结果】所得最适宜条件为：含Ca^₂₊复合富集剂用量为(m_氟/m_复合剂) = 1:1×10^₅,反应时间200min,反应温度22℃,反应体系酸度pH 5.5,搅拌速率200~300 r/min,沉淀物洗涤4次。该法的LOD_F = 5.3×10^_-3 μg/g,且c_F在1.0×10^_-6 mol/L ~ 1.0×10^_-1 mol/L内呈良好定量函数关系：E = 38.657 lgc - 174.44 (R2 = 0.996)。加标回收率为91.5 %~100.3 %,测定结果较稳定(RSD≤2.7%)。实样氟含量测定值符合GB 2762-2005氟限量要求。【结论】本法集合了富集反应的高倍放大的效果和双点电位滴定法的高精准的特点,测定选择性高,速度快,灵敏度较高,是种实用可靠的微量氟的定量分析方法。且有易于实现自动化和智能化快捷在线检测的潜能。     

电感耦合等离子体质谱法测定芦荟、人参、五味子、龙胆草中5种重金属含量

目的：建立用电感耦合等离子体质谱(ICP-MS)法测定辽宁地区芦荟、人参、五味子、龙胆草中铜、镉、铅、砷、汞5种重金属含量的方法。方法：微波消解法处理样品,采用ICP-MS法测定,射频功率1 500 W,采用碰撞模式,碰撞气为氦气,载气为氩气,载气流速0.7 L.min_^-1,等离子体气体流速15.0 L.min_^-1,泵速0.3r.s_^-1。结果：5种重金属线性关系良好(r>0.999 0)；加样回收率为89.8%～96.9%(n=6)；检测限为0.0002～0.006mg.kg_^-1。结论：本方法准确可靠、灵敏简便,可用于芦荟、人参、五味子、龙胆草中多种重金属的质量研究,同时为测定同类中药材中此5种重金属提供参考。S     

大叶千斤拔黄酮类成分提取及抗氧化活性研究

通过单因素试验及响应面试验优化大叶千斤拔总黄酮的乙醇回流提取工艺条件,并对提取物的抗氧化活性进行评价。结果表明：优化后的提取工艺条件为提取时间52 min,料液比（m_{大叶千斤拔}∶V_乙醇）1∶6 （g/mL）,乙醇体积分数70%,提取温度60 ℃,该条件下提取物的总黄酮含量为75.47 μg/mg;提取物对ABTS⁺自由基、DPPH自由基清除能力的IC₅₀分别为0.044 9,0.212 3 mg/mL,总抗氧化能力及对Cu²⁺和Fe³⁺还原能力的IC₅₀分别为0.389 6,0.221 9,0.731 7 mg/mL。说明建立的最佳提取工艺可有效获取大叶千斤拔总黄酮成分;大叶千斤拔黄酮类物质具有较强的体外抗氧化活性。     

在线凝胶渗透色谱-气相色谱-串联质谱法测定食用植物油中11种有机磷阻燃剂

目的 建立在线凝胶渗透色谱–气相色谱-串联质谱法(GPC-GCMS/MS)测定食用植物油中11种有机磷阻燃剂的分析方法。方法 0.5 g 食用油样品用(3：7)丙酮/环己烷溶液稀释定容至5 mL, GPC-GCMS/MS采用多反应监测模式(MRM)测定,外标法定量。结果 11种有机磷阻燃剂在1～50 μg. L_{^{－ 1}}范围内,线性关系良好,相关系数r>0.9970,方法检出限为1.0～3.0 μg. kg_{^{－ 1}},定量限为3.0～9.0 μg. kg_{^{－ 1}}。空白样品中添加3个水平质量浓度,回收率在65.6～129%之间,相对标准偏差RSD为0.2～13.9%。结论 该方法样品前处理简单,仪器自动化程度高,重现性较好,精密度较高,适用于食用植物油中有机磷阻燃剂的检测。     

Esters of para-aminobenzoic acid in cosmetics. Identification and dosage within sun-creams

A method is presented for the identification and determination by T.L.C. and G.L.C. of esters of para-aminobenzoic acid with a free amine function and of local anaesthetics, prohibited in cosmetic products, in accordance with the cosmetic directive 76/768/EEC. In a commercial product, nominally supplied as para-aminobenzoic monoglyceryl ester (authorised in sun-creams in accordance with the EEC directive) other phenyl groups with para substitution were identified by means of T.L.C. and N.M.R. spectroscopy; among them, the para-aminobenzoic ethyl ester. G.L.C. enables a quantitative determination of these substances. Les esters de l'acide para-amino benzoique dans les produits cosmétiques. Identification et dosage dans les crémes solaires     

argR基因对钝齿棒杆菌发酵过程中产精氨酸特性的影响

本文测定了一株钝齿棒杆菌（Corynebacterium crenatum）诱变菌和二株基因工程菌发酵过程中产arginine曲线、生长曲线以及发酵液中碳源消耗量和pH值的变化。实验结果显示Arg产量最高的菌株为C．crenatumA．S．M2.sp，其产量达到9mg／ml，据此认为钝齿棒杆菌中的argR基因可能为Arg代谢中的一个正调控因子。     

The distribution of anthocyanins in grape skin extracts of port wine cultivars as determined by high performance liquid chromatography

The distribution of anthocyanins in methanolic skin extracts of 16 grape cultivars used for port wine production and grown at five sites in the Douro Valley in Northern Portugal has been assessed by high performance liquid chromatography. Results are confined to the seven most readily separated and identified anthocyanins and are expressed as percentages of their total (88–99% of the total integrated area). Anthocyanins based on malvidin (Mv) predominated. Of these, Mv 3-glucoside was the major pigment (33–60%), being exceeded by Mv 3-p-coumarylglucoside (2–51%) in only two cultivars; Mv 3-acetylglucoside (1–15%) was consistently the lowest. Peonidin 3-glucoside (1–27%) was prominent in four cultivars, but delphinidin 3-glucoside (1–11%), petunidin 3-glucoside (2–11%) and cyanidin 3-glucoside (trace-6%) were of low proportions throughout. The ratio Mv 3-acetylglucoside/total Mv glucosides appeared characteristic of cultivar, independent of site, and a useful aid to identification of grape cultivars. The coloured pulp of some cultivars contained peonidin 3-glucoside as a major component, present in greater proportions than in the skin; the percentage of Mv 3-p-coumarylglucoside was lower in pulp than in skin. The identities of six of the seven anthocyanins were confirmed by fast atom bombardment mass spectrometry and the structures of the Mv derivatives were determined by nuclear magnetic resonance. The formation of formyl and acetyl anthocyanin artefacts is described.     

The saponin content and sapogenol composition of the seed of 13 varieties of legume

The total saponin content of various legume seeds together with their sapogenol composition have been determined. Extraction of the defatted flours was effected with methanol and subsequent acid hydrolysis yielded the soyasapogenols which were analysed using gas and thin-layer chromatography. The saponin levels ranged from 0–0.65% for defatted seed while the major sapogenol present in these saponins was soyasapogenol B. The figures obtained are compared with those previously reported and reasons are suggested for the discrepancies.     

The determination of bitter principles in zucchinis

A method using reverse phase thin layer and high performance liquid chromatography was developed to determine the level of the bitter principle occasionally found in zucchini (Cucurbita pepo L.). The system gave excellent separation with recovery rates of about 90% from spiked fruit. The bitter principle was confirmed by C¹³ NMR and mass spectrometry as cucurbitacin E glycoside which was present in concentrations in the order of 600mg kg^?1 in bitter fruits. Bitterness was detected by a taste panel at cucurbitacin E glycoside concentrations of 1 mg kg^?1 in aqueous solutions and 2 mg kg^?1 in zucchini pulp. The method described should assist the screening for bitterness in commercial and breeding populations of zucchini.     

设施栽培条件下葡萄光合特性初探

利用电子光合测定仪，对设施栽培条件下“乍娜”、“凤凰５１”品种的光合特性进行研究，结果表明葡萄光合日变化呈明显的双峰型，两品种光合峰值及光合低谷期长短有明显不同。在华北地区，影响设施内葡萄光合效率的主要生态因素是ＣＯ２浓度和水分状况，尤其是设施内相对湿度和光合效率有明显相关。     

利用SDS-PAGE电泳对啤酒生产过程中蛋白质动态变化的研究

采用SDS -PAGE电泳,对青岛啤酒酿造过程中的可溶性蛋白质变化进行了动态的跟踪。发现制麦和糖化过程是蛋白变化最明显的阶段,蛋白的分布和含量整体呈下降趋势。啤酒和啤酒泡沫中蛋白的分布较接近,主要表现为4 .3万的窄带和0 .7- 1.4万的宽带电泳图谱分布。     

Wine phenolics—analysis of low molecular weight components by high performance liquid chromatography

Low molecular weight phenolic compounds were separated by high performance liquid chromatography on hydrocarbon-bonded reverse phase packings, with a water-methanol elution gradient. Phenolic compounds were extracted from wine with ethyl acetate. A first extraction at pH 7 enabled isolation of neutral molecules (catechins, procyanidins, flavonols, aromatic alcohols); a second extraction at pH 2 was performed to extract phenolic acids. Successive injections of these two extracts in the chromatograph gave the distribution of the different phenolic compounds in the wine under analysis. Analytical data are given for low molecular weight phenolic compounds present in young red Bordeaux wines from different vine cultivars.     

Presence of quercetin-3-O-glucuronoside in Spanish table wines

Quercetin-3-O-glucuronoside has been identified in several Spanish table wines by thin-layer (t.l.c.) and high-performance liquid (h.p.l.c.) chromatographic methods. This is thought to be the first report of its occurrence in wine.