电感耦合等离子体质谱法检测新食品原料黑果腺肋花楸果中的20种营养元素

目的：建立用电感耦合等离子体质谱(ICP-MS)法测定辽宁地区新食品原料黑果腺肋花楸果中20种营养元素(钾、钙、锰、铁、铜、锌、锶、锂、钠、镁、铝、磷、钛、钴、镍、钼、锡、锑、钡、硒)含量的方法。方法：微波消解法处理样品,采用ICP-MS法测定含量,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：20种营养元素线性关系良好(r>0.9998 0)；加样回收率为89.7%～101.6%(n=6)；检测限为0.010～1.0mg.kg_^-1。结论：本方法准确可靠、灵敏简便,可用于辽宁地区新食品原料黑果腺肋花楸果中多种营养元素的质量研究,同时为测定同类新食品原料中此20种营养元素提供参考。S     

电感耦合等离子体-质谱法测定黑果腺肋花楸果中有机硒含量

目的：研究建立了辽宁地区新食品原料黑果腺肋花楸果中有机硒的定性分离和定量测定方法。方法：以黑果腺肋花楸果为主要研究对象,通过有机超声离子提取、离心分离、环己烷萃取的方法进行有机硒的分离,再将其通过使用硝酸进行湿法消解,6Smol/L的盐酸溶液进行还原,使用ICP-MS法对其进行定量分析测定,并通过对前处理条件进行优化,以及仪器条件进行对比研究,选择出最优条件及参数,射频功率1 500 W,采用碰撞模式,载气为氩气,流速0.7 L.min_^-1,碰撞气为氦气,等离子体气体流速18.0 L.min_^-1,泵速24rpm。结果：对标准曲线线性、检出限、精密度、加标回收率等进行了研究。测定结果表明,该方法的线性相关系数良好(r>0.9991),精密度较低4.7%,加标回收率在95.1%(n=6)。结论：该方法简单、快速、准确、灵敏、回收率高,适用于辽宁地区新食品原料黑果腺肋花楸果中有机硒的分离测定,同时为测定同类新食品原料中有机硒元素含量提供参考。     

磷钾肥对云南旱作马铃薯产量和养分吸收的影响--测试文章

在云南省曲靖地区的低肥力和中高肥力试验地分别开展旱作马铃薯的田间小区试验,研究磷钾施用量对马铃薯生物量、养分利用、产量和经济效益的影响。结果表明：相同施肥量的条件下,中高肥力试验地的东山组马铃薯产量远高于低肥力的越州组,产量相差10 305.00～20 140.20 kg·hm^-2;越州组NP2K3(N,150 kg·hm^-2; P₂O₅,90 kg·hm^-2; K₂O, 405 kg·hm^-2)处理产量产值最高,NP2K1(N,150 kg·hm^-2; P₂O₅,90 kg·hm^-2; K₂O, 135 kg·hm^-2)处理净收益最高; 东山组NP2K2(N,150 kg·hm^-2; P₂O₅,90 kg·hm^-2; K₂O, 270 kg·hm^-2)处理产量、产值及净收益均是最高; 两组试验的马铃薯干重变化趋势相似,NP2K2处理的干重积累量较多,无钾无磷处理干重积累少;马铃薯体内累积K最多,其次为N,最后为P, NPK养分吸收积累的高峰期在马铃薯块茎膨大期到淀粉积累期; 东山组的马铃薯PK利用效率明显高于越州组。NP1K2(N,150 kg·hm^-2; P₂O₅,45 kg·hm^-2; K₂O, 270 kg·hm^-2)处理的P肥利用率和P素农学效率较高,P肥利用率和P素农学效率都有随施P量增加而降低的趋势。NP2K1处理的K肥利用率和K素农学效率最高,K肥利用率和K素农学效率均有随施K量增加而降低的趋势。     

重金属镉人工抗原的制备与鉴定

目的 制备重金属镉人工抗原并对其进行理化性质和免疫原性鉴定。方法 以乙二胺四乙酸二钠(EDTA.2Na)或二乙基三胺五乙酸(DTPA)为双功能螯合剂,将牛血清白蛋白(BSA)和Cd_²⁺进行螯合,制备镉人工抗原,通过二喹啉甲酸(BCA)法、紫外全波长扫描、聚丙烯酰胺凝胶电泳(SDS-PAGE)、火焰原子吸收法以及动物免疫的方法对人工抗原进行分析鉴定。结果 紫外全波长扫描和SDS-PAGE电泳初步证明人工抗原合成成功;BCA法测定人工抗原BSA-EDTA-Cd_²⁺和BSA-DTPA-Cd_²⁺的蛋白质浓度分别为0.9488、0.5506 mg/mL;火焰原子吸收法测得BSA-EDTA-Cd_²⁺和BSA-DTPA-Cd_²⁺的Cd_²⁺浓度分别为22.8、20.1 μg/mL,说明人工抗原合成成功,且BSA-EDTA-Cd_²⁺和BSA-DTPA-Cd_²⁺的偶联比分别为14.2：1和21.6：1;用BSA-EDTA-Cd_²⁺和BSA-DTPA-Cd_²⁺分别免疫小鼠,四免后血清效价均能达到1：25600,且两组血清敏感性分别达到208.63和98.43 ng。结论 人工抗原BSA-EDTA-Cd_²⁺、BSA-DTPA-Cd_²⁺合成成功,为制备单克隆抗体和建立重金属镉快速免疫分析技术提供研究基础。     

粉葛愈伤组织不同极性提取物生物活性与功能成分分析

目的 为探究粉葛愈伤组织次生代谢产物的生物活性和功能成分。方法 采用系统溶剂法制备粉葛愈伤组织石油醚提取物(petroleum ether extract,PE)、乙酸乙酯提取物(ethyl acetate extract,EE)、甲醇提取物(methanol extract,ME)和水提取物(water extract,WE)等4种不同极性次生代谢产物,利用8株细菌、2个自由体系和1个细胞系测试四种提取物的抗菌、抗氧化和细胞毒活性,分析4种提取物中总黄酮、总酚、总多糖等主要功能成分含量与生物活性的相关性,并运用高效液相色谱法(high performance liquid chromatography,HPLC)检测其单体功能成分。结果 四种提取物的生物活性显著差异,其中EE对粪肠球菌、金黄色葡萄球菌、藤黄微球菌等革兰氏阳性菌作用突出,其最小抑菌浓度(minimum inhibitory concentration,MIC)为0.195~0.391 mg.mL_-1^,EE对1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)和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)自由基清除能力均最佳,其半抑制浓度(half maximal inhibitory concentration,IC₅₀)分别为0.2795和0.0640 mg.mL_-1^,EE对人肺癌细胞A549(human lung cancer cell)的抑制能力较佳,其半最大效应浓度(concentration for 50% of maximal effect,EC₅₀)为260.9 μg.mL_-1^{。总黄酮和总酚在}EE中含量均最高,分别为(273.89±7.48)μg.mg_-1^和(261.00±14.94)μg.mg_-1^,总多糖在WE中含量最高,达到(402.25±13.49)μg.mg_-1^,相关性分析显示,总黄酮为重要的抗菌和抗氧化活性成分。异黄酮单体功能成分在四种提取物中组成和含量差异均较大,且主要集中在EE和ME,其中EE以大豆苷(30.3428±1.4251)μg.mg_-1^{和大豆苷元}(45.7235±2.0230)μg.mg_-1^为主,ME以大豆苷(60.0125±3.9250)μg.mg_-1^{和染料木苷}(20.5655±1.3025)μg.mg_-1^为主。结论 粉葛愈伤组织次生代谢产物具有较强的抗菌、抗氧化活性以及微弱的细胞毒活性,主要含有大豆苷、染料木苷和大豆苷元等功能成分,该结果为粉葛愈伤组织次生代谢产物在食品与制药领域的开发利用提供了一定的参考。     

仿刺参精、卵多肽体外抗氧化及对H2O2诱导巨噬细胞氧化损伤的保护作用

目的 为研究仿刺参精、卵多肽体外抗氧化及对H₂O₂诱导巨噬细胞氧化损伤的保护作用。方法 采用切向流超滤法对多肽进行分级制备,通过测定清除1,1-二苯基-2-苦基苯肼自由基(DPPH.)、羟基自由基(.OH)和超氧阴离子自由基(O_2^-.)的能力来评价体外抗氧化活性,并对多肽的相对分子质量(Mr)、氨基酸(AA)组成及氧化稳定性进行检测分析,通过构建氧化损伤细胞模型,考察多肽对H₂O₂诱导RAW 264.7巨噬细胞氧化损伤的保护作用。结果 仿刺参精、卵多肽均具有较强的清除DPPH.、.OH和O_2^-.能力,并且在一定范围内呈现量效关系,Mr<1×10^₃ Da的多肽AJS1和AJE1抗氧化活性表现更强,两者Mr 95.56%和91.89%在1×10^₃ Da以内,疏水性AA和酸性AA比例均较高,并具有极佳的耐盐性和热稳定性,但在贮存和加工过程中仍要注意过酸环境和金属离子对氧化稳定性的影响。所有多肽组对巨噬细胞不存在毒性影响,并且多肽质量浓度为200、400 μg/mL时均对H₂O₂损伤的RAW 264.7巨噬细胞体现出显著的保护作用(P<0.05)。结论 仿刺参精、卵多肽具有良好的体外抗氧化和对氧化损伤细胞的保护作用,具有开发为功能性食品、医药和化妆品等的潜力。     

苦荞脆片挤压工艺优化及品质特性研究

以即食膨化苦荞脆片为研究对象,在单因素试验基础上,选取喂料速度、套筒温度、螺杆转速、物料含水率为影响因素,以膨化度、密度、硬度、酥脆性、色差、总黄酮含量为考察指标进行响应曲面试验设计。通过因子分析方法,对苦荞脆片产品进行综合评价,构建综合评分的回归方程,优化后得到挤压工艺参数优化范围：喂料速度为10.4~11.3 kg.h^-1,套筒温度为115~118℃,螺杆转速344~358 r.min^-1,物料含水率为23.8~25.3%,在此范围内选取喂料速度为11kg.h^-1,套筒温度为116℃,螺杆转速为350r.min^-1,物料含水率为25%,该条件下生产苦荞脆片的综合评分理论预测值为0.89,验证试验得出综合评分的实际值为0.86,实测结果与预测值吻合良好。通过各品质指标之间相关性分析得出：苦荞脆片总黄酮含量越高,其膨化度和酥脆性越低,密度和硬度越高。     

电感耦合等离子体质谱法检测小浆果中6种重金属含量

目的：应用电感耦合等离子体质谱仪( ICP-MS) ,建立树莓、蓝莓、黑加仑、软枣猕猴桃、无梗五加等小浆果中砷(As)、铅(Pb)、镉(Cd)、铬(Cr)、汞(Hg)、铜(Cu)6种重金属的测定方法。方法：样品经微波消解,以锗(⁷²Ge)、铟(¹¹⁵In)、铋(²⁰⁹Bi)为内标,采用ICP-MS法同时测定上述7种元素的含量。结果：对于各测定元素,标准曲线的相关系数r≥0.9990,回收率为80.6%～97.3 %,相对标准偏差为1.1%～5.5%。结论：该方法简便、快速、准确,可用于小浆果中这6种重金属的含量测定。     

电Fenton技术深度处理造纸废水

采用电Fenton技术深度处理二级生化后的造纸废水,以色度去除率和COD去除率为主要考察指标,研究不同因素对造纸废水深度处理效果的影响。反应的最佳条件为：反应时间120 min、初始pH值=3、电压12 V、Fe²⁺浓度0.8 mmol/L、H₂O₂浓度0.8 mmol/L、极板间距10 cm、电解质Na₂SO₄浓度6 g/L。最佳反应条件下,电Fenton法对造纸废水的色度去除率和COD_Cr去除率分别达到89.5%和68.4%。动力学分析表明,电Fenton技术对造纸废水COD的降解符合一级反应动力学规律,一级反应速率常数为k=0.2072 min^-1。     

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。     

离子色谱法同时测定蛋白胨中葡萄糖、果糖、蔗糖、麦芽糖、乳糖含量

目的建立离子色谱法同时检测蛋白胨中葡萄糖、果糖、蔗糖、麦芽糖、乳糖的分析方法。方法样品用水作为提取剂,用OnGuard Ⅱ RP柱和OnGuard Ⅱ H柱净化,50mmol/LNaOH溶液作为流动相,用Carbopac PA20柱进行离子色谱分析。结果在该条件下5种糖都能得到较好分离,线性良好,葡萄糖、果糖、蔗糖、乳糖和麦芽糖的检出限为0.002、0.004、0.011、0.007、0.018 mg/L,平均回收率为90.59%～97.68%(n=9)。结论该方法操作简便、灵敏度高,可用于作为蛋白胨中葡萄糖、果糖、蔗糖、麦芽糖、乳糖的检测。     

拟穴青蟹新型过敏原肌质钙结合蛋白的纯化、鉴定及分子克隆

为进一步认识蟹类的过敏原,采用免疫印迹方法,分析发现甲壳类过敏患者血清能与拟穴青蟹肌浆蛋白中分子质量约为21 kD的蛋白质产生特异的IgE结合反应,结果显示该蛋白可能是蟹类新型过敏原。通过硫酸铵盐析、阴离子交换和凝胶过滤柱层析等方法对21 kD-蛋白进行分离纯化,采用Western blotting和基质辅助激光解析电离飞行时间质谱（matrix assisted laser desorption ionization-time of flight-mass spectrometry,MALDI-TOF-MS）确认纯化的21 kD-蛋白为肌质钙结合蛋白（sarcoplasmic calcium binding protein,SCP）。采用SMART-RACE（SwitchingMechanism At RNA Termini-Rapid Amplification of cDNA Ends）的方法获得SCP的cDNA序列,该序列全长986 bp,开放阅读框为579 bp,编码193 个氨基酸,其理论分子质量21.94 kD,等电点4.44。拟穴青蟹SCP与甲壳类动物SCP具有较高的同源性,与昆虫SCP的同源性较差;三级结构模拟分析显示,SCP含有5 个螺旋-转角-螺旋结构区,即EF-手型结构区,并在其中两个手型结构区形成2 个钙离子结合位点;进一步预测得到SCP的4 个线性抗原表位和3 个构象性抗原表位。     

Impact of transglutaminase on the textural, physicochemical, and structural properties of chicken skeletal, smooth, and cardiac muscles

This study examined the effects of microbial transglutaminase (MTG; 3.1 mg/ml) on chicken skeletal, smooth, and cardiac muscles; the meat containing the different muscle types was shaped into sausages and treated at 40 °C and/or 78 °C for 30 min. Although the three muscle types were obtained from the same bird, the effects of MTG addition were not uniform. All the muscle types showed a significant increase in the breaking strength (P < 0.01), but skeletal muscle exhibited the maximum increase. All samples showed a decrease in the fluorescence intensity and a significant reduction in the concentration of proteins that were extracted in a high ionic strength solution (P < 0.05). Scanning electron microscopy images and histological studies revealed that different muscle types had different physical structures and frameworks after MTG treatment, which is a reflection of the differences in the reaction specificity of MTG with different muscle proteins. Histological studies revealed that the reactions of MTG with meat proteins are both exogenous and endogenous. Cooking loss data suggested that MTG did not have any negative effect on water retention during cooking. MTG appears to be a functional and contributive substance since the results suggest that MTG can function on all muscle types that are mechanically processed for different industrial applications. MTG aggregates muscle proteins in different ways that improve their organoleptic properties such as texture, appearance, and water retention.     

Determination of Zn,Cu, Cd,Pb, Ni and Cr in some Slovenian foodstuffs

An acid-assisted microwave digestion procedure was optimised for the determination of trace elements in foodstuffs by the use of flame and electrothermal atomic absorption spectrometric (FAAS, ETAAS) techniques. Zn, Cu, Cd, Pb, Ni and Cr were determined in cabbage, wheat, potato, instant milk, fish, eggs and baby foodstuffs. The repeatability of measurements was tested in the cabbage sample and was found to be ±3.3% for Zn, 4.6% for Cd, ±6.8% for Cu and ±15.5% for Cr. The worse value obtained for Cr was probably due to its inhomogeneous distribution and very low concentration in the cabbage. Concentrations of Ni and Pb in the cabbage sample were below the limit of detection (0.2 mg kg^–1). The accuracy of the analytical procedure was checked by the analysis of the standard reference material CRM 1570 Trace and minor elements in spinach leaves and IAEA 336 Trace and minor elements in lichen. Good agreement between the certified or indicative and determined values was obtained. The results indicate that the concentrations of Zn, Cu, Cd, Pb, Ni and Cr found in cabbage, wheat and potato are comparable to the literature data. Cd, Pb and Ni were not found to be the contaminants in the foodstuffs analysed. Higher concentrations of Ni were found only in baby food "okolenik", arising from the cocoa that "okolenik" contained. It was demonstrated that the Cr content is very low in baby food, yolk and white of egg and in fish (<0.05 mg kg^–1 Cr). Elevated concentrations of trace elements were found only in mussels that accumulate heavy metals from the marine environment.     

Pilot survey of commercial pasteurized milk consumed in the metropolitan area of Rio de Janeiro,Brazil, for tetracyclines residues,including the 4-epimers of oxytetracycline,tetracycline and chlortetracycline

This pilot survey aimed to assess the occurrence of tetracyclines and the 4-epimers of oxytetracycline, tetracycline and chlortetracycline in commercial pasteurized milks sold in the metropolitan area of Rio de Janeiro, Brazil, between October 2009 and March 2010. A liquid chromatography–tandem mass spectrometry (LC–MS/MS) method, developed and validated in our laboratory, was used. All 100 analyzed samples were compliant, but 14 contained oxytetracycline in concentrations ranging from the method limit of detection (3.7?µg?l^–1) to the method limit of quantification (12.2?µg?l^–1). One sample contained oxytetracycline and tetracycline simultaneously (at a concentration slightly higher than method limit of quantification, 7.0?µg?l^–1). The presence of 4-epioxytetracycline and 4-epitetracycline in contaminated samples with the parent drugs could not be confirmed as traces were detected only in the quantification MRM transition. No other tetracyclines were detected.     

Bioactive compound content,antioxidant activity,deoxynivalenol and heavy metal contamination of pearled wheat fractions

Wheat kernels are rich in antioxidant compounds, that are mainly present in the outer bran layers and which are removed during milling. Unfortunately, several contaminants, e.g., mycotoxins and heavy metals, are also concentrated in the external layers. Pearling of 3 wheat varieties gave five fractions (each 5% of the original grain weight), starting from the outer layer until the inner kernel, designated as 0–5%, 5–10%, 10–15%, 15–20%, 20–25%, respectively. The remaining 75% of the inner kernel was also collected. Dietary fibre, free phenolic acids and total antioxidant activity decreased progressively from the external to the internal layers. However, the 5–10% fraction was richer in β-glucan content than the external one (0–5%). Heavy metals were only found in the most external fraction. Deoxynivalenol contamination decreased from the external to the internal layers: 64% of total contamination of kernel was found in the 0–5% and 5–10% fractions. The 10–15% kernel fraction offered the best compromise between high nutritional value and low contamination risk.     

超声波对低嘌呤脱脂豆浆溶解性、保水性及粘度的影响

为了研究超声波处理对低嘌呤脱脂豆浆溶解性、保水性及黏度的影响,以脱脂豆粕为原料,采用超声波法,通过单因素及正交试验,研究最佳超声波处理条件.研究结果表明,最佳超声波处理条件为超声功率315 W、超声时间40 min、超声温度60℃,此条件下的黏度为1.4 mPa·s、保水性为81.83％、溶解性为58.15％.超声波处理的溶解性比未经超声波处理提高了22.35％.因此,超声波处理能显著提高低嘌呤脱脂豆浆的溶解性及低嘌呤脱脂豆腐的保水性,降低低嘌呤脱脂豆浆的黏度.     

高效液相色谱法同时测定可乐中苯甲酸、糖精钠、安赛蜜和咖啡因

目的建立高效液相色谱同时测定可乐中苯甲酸、糖精钠、安赛蜜和咖啡因的方法,并应用于国际FAPAS能力验证。方法样品经超声脱气用水稀释,采用C_(18)色谱柱分离,以乙酸铵缓冲液(0.02 mol/L)/甲醇为流动相,采用梯度洗脱分离,在230 nm、272 nm波长下进行检测。结果苯甲酸、糖精钠、安赛蜜和咖啡因线性范围为2.0~200μg/m L,线性关系良好,相关系数大于0.999,回收率在97%~103%之间,RSD为0.5%~2.8%之间,检出限在0.005~0.02μg/m L之间。结论该法灵敏度高、重现性好,用于FAPAS能力验证时结果接近中值。     

Amino acids,fatty acids,and dietary fibre in edible seaweed products

The nutritional compositions of 34 edible seaweed products of the Laminaria sp., Undaria pinnatifida, Hizikia fusiforme and Porphyra sp. varieties were analyzed.