柠檬黄着色剂标准样品制备中纯化工艺的研究

利用重结晶技术对柠檬黄着色剂进行纯化,以纯度为指标考察其纯化程度。通过试验,确定纯化柠檬黄着色剂的最佳工艺条件。结果表明:以3%氯化钠水溶液与95%乙醇组成的混合溶剂重结晶2次,再以2%乙酸钾溶液与95%乙醇组成的混合溶剂重结晶2次,后洗涤滤饼,并将滤饼经80℃烘干、粉碎后得到纯度为99.87%的柠檬黄着色剂纯品,符合标准样品的要求。     

Use of Red Cowpea in the Manufacture of Some Food Products

Cowpea flour, starch and protein were successfully used as substituents in a wide range of food products, either as protein supplements or alternative ingredients. Acceptable soft buns were produced from ingredients in which wheat flour was substituted at the level of 10%, by weight, with dry- or wet-dehulled cowpea flour, or 20% with dry-milled cowpea protein fraction. Protein-fortified cookies of satisfactory sensory quality could be produced by replacing up to 50%, by weight, of wheat flour in the recipe with either dry- or wetdehulled cowpea flour, or up to 35% with cowpea protein fraction. Acceptable emulsion-type sausage was produced by replacing 5%, by weight, of its lean pork with dry-milled cowpea starch or protein fraction, or wet-dehulled cowpea flour, or 10% with dry-dehulled cowpea flour. Transparent noodles produced from wet-milled red cowpea starch had similar quality to those from mung bean starch. When, cowpea flour or protein fraction was used as a substituent in the products, protein content of the products could increase by 4–72%.     

磁性印迹固相萃取-印迹电化学传感器联用技术快速检测肉制品中的红霉素

本文旨在构建一种简便、快捷的肉制品中痕量红霉素磁性分子印迹固相萃取-印迹电化学传感器联用的分析方法。采用新型表面印迹技术,制备出对ERY具有高选择性与灵敏性的红霉素磁性分子印迹聚合物（MMIP）,再分别以MMIP作为固相萃取剂及电化学传感元构建印迹固相萃取-印迹电化学传感器（MMISPE-MMIP-sensor）联用技术快速检测系统。采用循环伏安（CV）及差分脉冲伏安（DPV）等方法对其电学性能进行探讨,通过红外光谱、扫描电镜（SEM）和透射电镜（TEM）对其结构和形态进行表征。实验考察了缓冲溶液pH和孵化时间对印迹电极的影响。结果表明,最佳缓冲溶液pH为7.5,富集时间为10 min。在最优实验条件下,该印迹电极的响应电流△I_R与ERY浓度的负对数（-logC_[ERY]）在1.0×10?10~1.0×10?5 mol/L范围内呈良好的线性关系,相关系数为0.991,最低检出限为1.0×10?10 mol/L。以AZI、STM、ROX三种结构类似物为干扰物,研究该印迹电极对ERY的吸附选择性。结果显示,该印迹电极只对红霉素分子具有特异识别作用而呈现最大响应值（0.72 mA）。重现性和稳定性实验结果显示该电极具有良好的重现性和稳定性。联用检测结果显示通过磁固相萃取和印迹电化学双预浓缩过程将样品中ERY富集浓度提高了9~12倍。     

Application of ZnO/CNTs Nanocomposite Ionic Liquid Paste Electrode as a Sensitive Voltammetric Sensor for Determination of Ascorbic Acid in Food Samples

In this study, a simple and rapid analytical method development for ascorbic acid (AA) determination in food samples by using differential pulse voltammetry (DPV) method on ZnO/CNTs nanocomposite ionic liquid modified carbon paste electrode. For this, several parameters, such as ZnO/CNTs nanocomposite, ionic liquid ratio, and pH, have been studied. The cyclic voltammogram showed an irreversible oxidation peak at 0.61 V (vs. Ag/AgCl_sat), which corresponded to the oxidation of AA. Compared to common carbon paste electrode, the electrochemical response was greatly improved. Under the optimized conditions, the oxidation peak current of AA showed linear dynamic range 0.1–450 μmol l^?1 with a detection limit of 0.07 μmol l^?1, using the DPV method. The proposed sensor was successfully applied to the determination of AA in fresh vegetable juice, fruit juices and food supplement samples without previous preparation and was compared with a published electrochemical method.     

食品中氯霉素类药物残留量检测方法研究进展

氯霉素类是一种禁止在食用动物中应用的抗生素类药物,其残留将会影响人体健康和动物性食品的出口贸易。本文综述了氯霉素类药物在食品中的检测方法,主要有微生物法、仪器法(色谱法、电化学法、光度法)、免疫分析方法、传感器法、分子印迹法、生物芯片法等,并分析了各种方法的优缺点,最后对氯霉素类药物残留检测方法的趋势进行展望。以期对我国食品(尤其是动物性食品)中氯霉素类药物的残留检测方法提供一定的技术支持。     

荷移光度法测定食品中三聚氰胺的研究

通过实验筛选得到适合三聚氰胺的荷移剂——茜素红,并对茜素红荷移光度法测定三聚氰胺的条件进行了探讨,获得的最佳条件为:三聚氰胺水溶液与茜素红乙醇溶液中性下反应,温度20℃,pH 6.5～8,时间30 min,得n_(三聚氰胺):n_(茜素红)=1:1紫红色荷移络合物,在λ_(max)=560 nm下,测得摩尔吸光系数ε=7.44×10~4L·mol~(-1)·cm~(-1),在6.1×10~(-5)～1.22×10~(-3)mol·L~(-1)内符合比尔定律,线性方程为A=1.406×10~(-5) c-0.0463(r=0.9967)。该法对市售生姜、黄豆和奶粉中三聚氰胺含量测定的结果与GB/T 22388—2008 HPLC法一致,回收率71.1%～85.5%,RSD为2.9%～4.0%。此法操作易掌握,灵敏度高,结果较为满意,但样品的预处理稍繁琐。     

Analysis of Free and Total Sulfites in Food by Ion Chromatography with Electrochemical Detection

A sensitive and selective analytical technique for the determination of free and total sulfites in food was developed using ion chromatography with electrochemical detection. Free and total sulfites in three dehydrated foods were analyzed by extraction of the sulfites at pH 2.0 and 8.9, respectively, and separation on an anion exclusion column with 5 mM H₂SO₄, pH 2, solution as eluant. Using an electrochemical detector set at + 0.40 volts vs Ag/AgCl electrode, sulfites equivalent to 0.1 ppm SO₂ in the extract could be detected with detector response linear up to 6 ppm SO₂.     

An Electrochemical Nanosensor for Simultaneous Voltammetric Determination of Ascorbic Acid and Sudan I in Food Samples

In this work, we describe application of a high-sensitive electrochemical sensor for determination of ascorbic acid (AA) in the presence of high concentration of Sudan I in food samples. In the first step, we study synthesis and characterization of NiO/NPs with X-ray diffraction (XRD) method. In the second step, application of NiO/NPs describe in the preparation of carbon-paste electrode modified with (9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboximido)-4-ethylbenzene-1,2-diol (DEDED) as a high-sensitive and selective voltammetric sensor for determination of AA and Sudan I. The electrocatalytic oxidation of AA at the modified electrode was investigated by cyclic voltammetry, chronoamperometry and square wave voltammetry (SWV). For the mixture containing AA and Sudan I, the peaks potential was well separated from each other. Their square wave voltammetrics peaks current increased linearly with their concentration at the ranges of 0.01–600 and 0.5–1,000 μM, with the detection limits of 0.006 and 0.2 μM, respectively. Finally, the proposed method was also examined as a selective, simple, and precise electrochemical sensor for the determination of AA and Sudan I in real samples such as fruit juices, fresh vegetable juice, chilli sauce and tomato sauce.     

胶囊剂型保健食品生产过程微生物分布和溯源分析

分别对胶囊剂型保健食品不同时期生产过程中的人员手部、设备表面进行微生物污染调查,监测车间清洁卫生的质量变化,对典型的污染微生物进行分离鉴定,掌握各环节微生物菌群构成,评价企业生产过程微生物控制系统的有效性。结果显示,34份人员手部涂抹样本中大肠菌群、金黄色葡萄球菌的检出值均<10 CFU/手,菌落总数介于10~107 CFU/手;132份设备表面涂抹样本中大肠菌群、金黄色葡萄球菌的检出值均<0.4 CFU/cm2（设备表面）,菌落总数介于10~104 CFU/cm2。从样本中分离出46株微生物（其中细菌44株,真菌2株）进行菌种鉴定,优势种群为类芽胞杆菌属（Paenibacillus sp.）,占比为60.87%,其次是不动杆菌属（Acinetobacter sp.）、芽胞杆菌属（Bacillus sp.）和短杆菌属（Brevibacterium sp.）,占比均为4.35%。基于16S rRNA基因序列和MALDI-TOF蛋白指纹图谱对分离的类芽胞杆菌进行溯源分析发现在人员手部和设备之间存在交叉污染,且该菌长期定殖用于周转物料的容器表面,对产品质量控制存在潜在风险。     

红枣及其制品链格孢毒素的QuEChERS-UPLC-MS/MS检测方法建立及其污染分析

为进一步掌握红枣中链格孢毒素的污染水平,本研究以市售红枣及其制品为研究对象,探索以QuChERS为核心的真菌毒素提取方法,建立超高效液相色谱-串联质谱的红枣5种链格孢毒素分析技术,并分析了红枣及其制品中链格孢毒素的污染水平。结果表明:采用QuChERS方法提取固体样品中链格孢毒素回收率在74.89%~98.04%;采用固相萃取法提取液体样品中链格孢毒素回收率在68.35%~99.63%,相对标准偏差均小于10%。对阿克苏、喀什、和田三个地区的骏枣原料中5种链格孢毒素进行测定,共检出细交链孢菌酮酸（TeA）、交链格孢酚（AOH）2种毒素,其中喀什地区红枣中TeA最高,达到5.12~10.76 μg/kg。在11种红枣制品中检出TeA、AOH、ALT 3种链格孢毒素,其中红枣酒中TeA达到127.08 μg/kg,仅紫晶枣中检出AOH,含量在34.76~98.61 μg/kg;在冻干枣片、香酥脆枣、紫晶枣中检出ALT,含量在2.04~399.64 μg/kg。本文建立的UPLC-MS/MS方法可满足不同形态红枣样品中链格孢毒素的测定要求,为红枣的食用安全提供理论依据。     

A Simple and Sensitive Method for the Voltammetric Analysis of Theobromine in Food Samples Using Nanobiocomposite Sensor

Theobromine (TB) is one of important natural methylxanthine alkaloids in plants and their products, but there were few reports on the electrochemistry of TB, especially electrochemical measurements using chemically modified electrode owing to its poor detectability. In this work, a simple and sensitive method for the voltammetric analysis of TB in green tea, chocolate, and coffee samples was successfully realized using nanobiohybrid sensor based on glassy carbon electrode (GCE) modified by both carboxyl-functionalized multiwalled carbon nanotubes (fMWCNTs) and soluble biopolymer sodium salt of carboxymethylcellulose (CMC). Water-dispersible nanonbiohybrids with fMWCNTs were successfully prepared using CMC assist, and CMC-fMWCNTs were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, transmission electron microscope, electrochemical impedance spectroscopy, and cyclic voltammetry. CMC-fMWCNTs/GCE showed enlarged electrochemically active surface area, good electrode stability, and enhanced electrocatalytic activity. The voltammetric behavior of TB demonstrated an irreversible electrochemical oxidation reaction involving two electrons and two protons, which could detect TB in a wider linear range from 0.5 to 80 μM with a lower limit of detection (LOD) of 0.21 μM. The developed method displayed a high sensitivity, low LOD, good sensing stability, remarkable feasibility, and satisfactory practicality.     

MnO2/ZnO/GCE电化学传感器的构建及对蜂蜜中磺胺甲恶唑的检测

为快速检测蜂蜜中磺胺甲恶唑(sulfamethoxazole,SMZ)的残留,将水热法制备的氧化锌(ZnO)及共沉淀法制备的二氧化锰(MnO₂)材料复合于玻碳电极(GCE)上,构建了MnO₂/ZnO/GCE电化学传感器用于检测SMZ。采用扫描电镜(SEM)及红外光谱(FT-IR)对复合材料的形貌、结构进行表征。利用差分脉冲伏安法(DPV)对复合材料的比例、修饰量进行探究,从而对传感器的构建条件进行优化。并采用差分脉冲伏安法(DPV)及循环伏安法(CV)对缓冲溶液pH、扫描速率等检测条件进行考察。结果表明,当m(ZnO):m(MnO₂)质量比为1:0.6、MnO₂/ZnO复合材料修饰量为1.7×10-3 mg/mm2、缓冲溶液pH为8、扫描速率为30 mV/s时,该传感器对SMZ具有良好的检测效果。在0.3～100μmol/L范围内,峰电流与SMZ浓度呈良好的线性关系,其线性方程为Ip=0.0843 c+4.5168(R2=0.9916),检测限为0.39μmol/L,定量限为1.30μmol/L。将...     

聚嘧啶/石墨烯复合材料修饰电极同时测定日落黄和酒石黄

采用液相剥离法制备石墨烯纳米片悬浮液,将其直接滴涂于玻碳电极表面,制备石墨烯修饰电极,再采用电沉积法制得聚嘧啶/石墨烯复合膜修饰电极。采用扫描电子显微镜对该修饰电极的表面形貌进行表征;采用循环伏安法和方波伏安法探究日落黄和酒石黄在该修饰电极上的电化学行为。结果表明,该复合膜修饰电极对两种合成色素均表现出良好的电催化性能。在优化实验条件下,日落黄和酒石黄同时被检测,线性检测范围分别为0.002~2?mol/L和0.003~6?mol/L,检测限分别为0.5 nmol/L和0.9 nmol/L。该方法可用于食品中日落黄和酒石黄的同时测定。     

传统发酵食品中具有抑菌活性乳酸菌筛选及其代谢产物稳定性分析

本文以传统发酵食品中筛选的39株乳酸菌为研究对象,采用牛津杯法筛选具有优良抑菌特性的乳酸菌,分别对菌株的生长曲线、产酸能力、耐胆盐、耐渗透压、耐酸碱、抑菌谱进行检测,并研究代谢产物的稳定性。结果表明：筛选出三株具有良好抑菌特性的菌株,分别为植物乳杆菌HS011、德氏乳杆菌HS023、嗜热链球菌HS033。三株菌经培养20 h后,发酵液pH分别由5.44、5.44、5.42下降到3.55、3.54、3.57;三株乳酸菌能耐受0.1%以下的胆盐和14%的NaCl溶液;在pH 5.0~8.0时生长情况良好;且具有较为广泛的抑菌谱,对大肠杆菌O157:H7、蜡样芽孢杆菌、单增李斯特氏菌、阪崎肠杆菌等均有较好抑制作用,但对霉菌和酵母无作用;代谢产物经温度（20~121 ℃）、pH（2.0~8.0）处理后仍有较好抑菌活性;经木瓜蛋白酶、胰蛋白酶、胃蛋白酶、蛋白酶K、过氧化氢酶处理后菌株代谢产物抑菌活性未有明显变化。表明从传统发酵食品中筛选的乳酸菌具有良好益生特性,其代谢产物稳定性好,可作为发酵产品中的生产菌株,可进一步开发利用。     

食品接触用竹木制品中杀菌剂的研究进展

食品接触竹木制品如一次性竹木筷、竹木砧板等在我国家庭或工作生活中应用广泛。由于竹木的特殊质地,在其加工过程中可能会使用一些杀菌防腐剂来保证其使用性能并延长贮藏期限。经处理过的竹木制品中残留杀菌剂是否会迁移至食品中对人体产生危害以及如何检测残留杀菌剂等问题也引起了人们的关注。本文以食品接触用竹木制品中杀菌剂为研究对象,结合国内外竹木制品中杀菌剂的研究进展,综述了竹木制品中杀菌剂的分类、应用、限量标准和检测方法,并对杀菌剂在食品模拟物中的迁移规律进行归纳,为检测食品接触用竹木制品中杀菌剂的残留提供参考。最后对食品接触用竹木制品中杀菌剂现有检测技术和迁移研究存在的问题做出总结,并对其研究前景进行展望。     

三氟氯氰菊酯分子印迹电化学传感器的制备及其在粮谷快速分析中的应用

以三氟氯氰菊酯为模板分子,基于电沉积壳聚糖制备能够特异识别模板分子及其结构类似物的分子印迹电化学传感器,探索电沉积电位、电沉积时间对印迹传感器性能的影响。实验采用循环伏安法(CV)和差分脉冲伏安法(DPV)研究了传感器的电化学响应特性,并优化制备和检测条件,最终选择在-1.5V的电位下电沉积5min制备三氟氯氰菊酯分子印迹电化学传感器,并将该传感器应用于农产品中三氟氯氰菊酯残留的快速分析。结果表明,在最佳条件下,三氟氣氰菊酯在0.1～1.0μmol/L浓度范围内有良好的线性关系,检出限(S/N=3)为0.04μmol/L,样品加标回收率在81.2%～94.6%之间(n=5),相对标准偏差(RSD)≤4.1%。该传感器操作简便、检测快速灵敏、成本低、抗干扰能力强、稳定性好、具有良好的应用前景。     

食品中喹诺酮类抗生素的光学和电化学传感器检测方法研究进展

食品中喹诺酮类抗生素的残留危害食品安全,已经引起广泛关注。基于纳米材料制备的传感器具有实时分析、低检测限和分析所需的样品量小等多种优势,是目前喹诺酮类抗生素的现场检测技术研究的热点。本文介绍了荧光、比色、表面增强拉曼散射(SERS)、免疫层析(ICA)等光学传感器和基于不同纳米材料的电化学传感器在喹诺酮类抗生素检测中的应用,比较和分析了不同类型传感器的特点。并对量子点、上转换纳米粒子等纳米材料在光学传感器中的应用,以及碳纳米材料、金属纳米材料和氧化还原介质等在电化学传感器中的应用进行了综述并提出了展望,以期为食品中抗生素的检测和传感器的发展提供新的思路。     

基于RASFF通报分析我国食品接触用金属材料及制品安全

欧盟是中国食品接触材料及制品的主要出口地区之一,且出口数量近年来呈现逐年上升的趋势。本文通过分析2012~2016年欧盟食品和饲料快速预警系统(Rapid Alert System for Food and Feed,RASFF)对华食品接触材料及制品通报情况,总结其涉及的材质情况、风险项目等,发现食品接触用金属材料及制品是中国输欧食品接触材料及制品中的高风险产品,食品接触用金属材料及制品通报数量占通报总量的35.60%。重金属超标是通报中最主要的风险项目,其中重金属铬、锰、镍超标最为突出,并探讨了这些情况对我国食品接触材料及制品安全监管的启示。     

多重增敏环保型痕量铅电化学传感器研制

为改进铅电化学传感器的敏感性、稳定性、准确性和安全性,用碳酸羟基磷灰石高效富集Pb2＋,用离子液体（[BMIM]PF6）增加其导电性,加覆Nafion膜增加其敏感性与稳定性,共同修饰丝网印刷碳电极,构建一种多重增敏环保型快速检测痕量铅电化学传感器;优化检测条件后用方波溶出伏安法进行测定的结果为：
Pb2＋质量浓度在3～600 μg/L范围内呈现良好的线性关系,检出限为0.37 μg/L（RSN=3）,连续8 次测定的相对标准偏差为3.4%。茶叶样品检测结果与电感耦合等离子体质谱测定结果无显著性差异。本研究研制出一种环保、敏感、准确、经济、简便且可用于茶叶中痕量铅检测的新型电化学传感器。