电感耦合等离子体发射光谱法测定食品接触用无机材料及制品中13种重金属迁移量

目的 建立一种同时检测食品接触用无机材料及制品中13种重金属迁移量(铝、砷、钡、镉、钴、铬、铜、锰、镍、铅、锑、硒与锌)的电感耦合等离子体发射光谱(inductively coupled plasma atomic emission spectrometry, ICP-AES)法。方法 采用4%(V:V)醋酸溶液, 在特定迁移实验条件下, 避光浸泡试样, 优化仪器参数和实验条件, 用电感耦合等离子体发射光谱法同时测定浸泡液中13种元素迁移量。结果 该方法检出限为0.001~0.010 mg/L, 样品的加标回收率为90.8%~105.1%, 相对标准偏差为0.96%~3.89%。结论 该方法简便、快速、高效、灵敏度高, 为食品接触用无机材料及制品中多种痕量有害元素迁移量进行合理产品风险评估提供一种高效、可行的手段。     

食品接触用硅橡胶中8种金属元素的迁移分析

目的 研究食品接触用硅橡胶制品中8种金属元素(钡、锂、铜、铁、钴、锰、锌和铝)的迁移量。方法 以3%乙酸(m:V)作为食品模拟物, 利用电感耦合等离子体质谱法测定食品接触用硅橡胶中8种金属元素的迁移量。结果 各金属元素的线性范围在1~100 μg/L, 方法检出限在0.005~0.6 μg/kg之间, 加标回收率在88.4%~108.0%, 重复性测定相对偏差(n=6)在1.2%~3.6%之间。对20批次食品接触用硅橡胶制品中8种金属元素的迁移量进行测试, 发现7种金属元素(钡、锂、铜、铁、锰、锌和铝)均有检出。结论 该方法可以准确测定食品接触用硅橡胶中8种金属元素(钡、锂、铜、铁、钴、锰、锌和铝)的迁移量, 且检测结果显示随着迁移次数的增加迁移量逐渐降低。     

电感耦合等离子体质谱法分析铜材质食品接触用品中8种金属元素迁移量

目的 建立电感耦合等离子体质谱法分析铜材质食品接触用品中8种金属元素(铜、砷、镉、铅、铋、镍、锡、锑)迁移量的方法。方法 以5 g/L柠檬酸(m:V)作为食品模拟物, 利用电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry, ICP-MS)测定铜材质食品接触用品中8种金属元素的迁移量。结果 8种元金属素的线性范围在1~100 μg/L, 方法检出限在0.01~0.9 μg/kg之间, 加标回收率在90.3%~106.0%, 重复性测定相对标准偏差(n=7)在1.3%~3.4%之间。对10批次铜材质食品接触用品中8种金属元素的迁移量进行测试, 发现5种元素(铜、砷、铅、镍和锡)有检出。结论 该方法可以准确测定铜材质食品接触制品中8种金属元素(铜、砷、镉、铅、铋、镍、锡、锑)的迁移量, 检测结果显示随着迁移次数的增加, 大部分元素呈下降趋势。     

电感耦合等离子体质谱法测定食品包装材料中有害金属元素

建立了模拟物中有害金属元素的电感耦合等离子体质谱测定方法（ICP-MS）。采用4种不同的模拟物替代食品,浸泡与食品接触的塑料包装材料,目的在于研究包装材料中有害金属元素的迁移情况。分别采用食品模拟物（乙酸、水、乙醇和正己烷）浸泡塑料包装材料,采用电感耦合等离子体质谱仪进行测定,并优化了仪器的条件。乙酸和水的浸泡液可直接导入电感耦合等离子体质谱仪进行检测,正己烷经过减压蒸馏后用2%硝酸定容,乙醇溶液经过电热板驱赶后采用2%硝酸定容,采用外标法定量。该方法的加标回收率在97.1%～108.9%之间、精密度在1.0%～3.9%之间,均满足实验的要求。     

电感耦合等离子体发射光谱法测定食品接触用搪瓷制品中11种重金属迁移量

目的 建立电感耦合等离子体发射光谱法(inductively coupled plasma atomic emission spectroscopy, ICP-AES)同时检测食品接触用搪瓷制品中11种重金属(铝、砷、钡、镉、钴、铬、锰、镍、铅、锑、锌)迁移量的分析方法。方法 采用4%(V:V)乙酸溶液, 在特定迁移试验条件下, 避光浸泡试样, 优化仪器参数和实验条件, 用电感耦合等离子体发射光谱法同时测定浸泡液中11元素迁移量。结果 方法检出限为0.001~0.010 mg/L, 样品加标回收率为92.2%~105.5%, 相对标准偏差为0.91%~3.65%。结论 方法操作简便, 准确度好, 灵敏度高、检出限低, 为食品接触用搪瓷制品中多种痕量有害元素迁移量进行合理产品风险评估提供一种高效、可行的手段。针对国标GB 4806.3-2016《食品安全国家标准搪瓷制品》中理化指标与迁移试验提出合理建议。     

电感耦合等离子体质谱法同时测定食品接触用金属制品中16种金属元素的迁移量

目的 对食品接触用金属制品中16种金属元素在酸性条件(4%乙酸溶液)下迁移检测方法进行系统的研究。方法 结合食品接触用金属制品实际接触条件,选择4%乙酸溶液煮沸30min,重复三次前处理条件,两种适合的内标元素,采用了电感耦合等离子体质谱法同时测定16种元素进行检测。结果 该方法汞镉元素定量检出限为0.1μg /L,其余元素为0.5μg /L,线性范围宽,加标回收率结果令人满意,RSD在0.3%~7.4%(n=6),适合食品接触用金属制品中16种金属元素迁移量的检测。结论 通过比较检测数据,铝合金、铁制品中的砷、铝、铁元素迁移量较高,存在产品合格不安全的质量安全隐患,应该引起食品相关产品监督部门的高度重视！     

电感耦合等离子体质谱法检测食品接触用铝箔在不同迁移条件下的铝迁移量

目的系统研究食品接触用铝箔纸中铝的迁移条件和检测方法。方法结合食品接触用铝箔纸实际接触条件,模拟3种迁移实验条件,采用电感耦合等离子体质谱法进行对铝迁移量检测。结果该方法检出限为0.5μg/L,线性范围宽,加标回收率为87.0%～99.2%,相对标准偏差(relative standard deviation,RSD)在0.4%～5.5%(n=6)。结论建立的方法适合食品接触用材料铝箔在不同迁移条件下的铝迁移量的检测。     

应用ORS-ICP-MS测定欧盟食品接触塑料和容器中7种可迁移金属含量

根据欧盟法规10/2011食品接触材料及容器中的要求,采用带八极杆碰撞/反应池（ORS）的电感耦合等离子体质谱(ICP-MS)法测定食品接触材料及容器中Ba、Co、Cu、Fe、Li、Mn、Zn 7种可迁移金属含量,通过优化ICP-MS工作条件,降低了质谱干扰,对所测定元素,相关系数均大于0.999,方法检出限为0.4~16 μg/L,精密度<3.5%,回收率在86.2%~108.5%,该方法快速,方便,该方法满足欧盟法规的检测要求,适合出口食品接触材料和容器中可迁移元素的测定。     

超高效液相色谱法同时测定食品塑料包装材料中紫外吸收剂和抗氧化剂的迁移量

目的建立食品塑料包装材料中限用紫外吸收剂(UV-0、UV-9、UV-71、UV-326、UV-327、UV-234)和抗氧化剂(2246、425、TH-1790、3114和1076)迁移量的超高效液相色谱(ultra performance liquid chromatography,UPLC)测定方法。方法优化仪器条件及模拟液萃取条件,考察超纯水、3%乙酸水(V:V)溶液、10%乙醇水(V:V)溶液及95%乙醇水(V:V)溶液等4种食品模拟物中紫外吸收剂和抗氧化剂的迁移量,并将建立的方法用于市售样品迁移量的检测。结果 11种目标物质在相应的浓度范围内线性关系良好,相关系数r~2大于0.9992,方法检出限为0.5~2.0 mg/L;平均加标回收率为81.2%~113.2%,相对标准偏差(n=6)为2.8%~8.5%。结论该检测方法灵敏、准确,满足欧盟指令(EU)No.10/2011和GB 9685-2008对食品塑料接触材料及制品中紫外吸收剂和抗氧化剂特定迁移量(SML)的限量要求,适用于食品塑料包装材料中紫外吸收剂和抗氧化剂的迁移量的测定。     

食品接触材料中纳米银迁移行为研究

目的研究纳米银在不同食品模拟液中的迁移情况。方法采用电感耦合等离子体原子发射光谱法(ICP-AES)检测了纳米银保鲜盒中纳米银的含量,比较了微波消解和干法灰化的前处理效果,并研究了不同温度情况下,纳米银食品接触材料在脂肪类(正己烷)、酸性(4%乙酸)、酒精类(65%乙醇)和水性(去离子水)食品模拟液中的迁移行为。结果食品模拟溶液、温度对纳米银的迁移有影响,其中纳米银在脂肪类模拟液中的迁移速度最快,在65%乙醇中迁移速度最慢。由Fick扩散模型,建立了PVC中塑化剂的迁移规律数学模型,得到了模型的重要参数。结论本研究成果能够对食品接触材料中纳米银的安全性评价提供技术支持。     

Natural pigments: carotenoids, anthocyanins, and betalains--characteristics, biosynthesis, processing, and stability

Pigments are present in all living matter and provide attractive colors and play basic roles in the development of organisms. Human beings, like most animals, come in contact with their surroundings through color, and things can or cannot be acceptable based on their color characteristics. This review presents the basic information about pigments focusing attention on the natural ones; it emphasizes the principal plant pigments: carotenoids, anthocyanins, and betalains. Special considerations are given to their salient characteristics; to their biosynthesis, taking into account the biochemical and molecular biology information generated in their elucidation; and to the processing and stability properties of these compounds as food colorants.     

Hormones, metabolites, and reproduction in Holsteins, Jerseys, and their crosses

Holsteins (HH), Jerseys (JJ), and their crosses in first (n=157) and second (n=107) lactation were used to determine if reproduction, progesterone (P4), insulin-like growth factor 1 (IGF-1), insulin, nonesterified fatty acids (NEFA), and milk production differed between genetic groups. Thirty-four cows were Holstein-Jersey (HJ) crosses, 46 were Jersey-Holstein (JH) crosses, 48 were purebred Holsteins (HH), and 29 were purebred Jerseys (JJ) in first lactation, whereas the second-lactation animals included 23 HJ, 35 JH, 35 HH, and 14 JJ. Blood samples were collected weekly for the first 10 wk postpartum. Analyses were conducted using the MIXED, chi-square, and GLIMMIX procedures (SAS Institute Inc., Cary, NC). Seasons of calving were cold (November to May) and hot (June to October) and were combined with year to form 8 year-seasons. Days open and number of services were affected by genetic group. The HH were open 169±8 d, which was greater than HJ (143±9 d), JJ (132±10 d), and JH (127±8 d). The HH had 2.4±0.1 services per pregnancy, which was greater than JH (1.9±0.1), but not different from HJ (2.1±0.2) or JJ (2.1±0.2). Concentrations of NEFA were greater in lactation 2 (0.52±0.02 mEq/L) than in lactation 1 (0.45±0.02 mEq/L) and decreased over the 10-wk period. Concentrations of NEFA were greater in the cold season except in yr 3. Insulin in lactation 1 (0.81±0.03 ng/mL) was greater than in lactation 2 (0.72±0.03 ng/mL); insulin decreased to wk 2 then gradually increased. The HJ had the greatest insulin concentrations (0.87±0.04 ng/mL) and the JJ had the lowest (0.66±0.04 ng/mL), and IGF-1 gradually increased over the 10-wk period. Milk production (actual yield in the first 305 d, not adjusted for fat and protein) was affected by genetic group, lactation number, year-season, and wk 1 insulin. The HH produced 10,348±207 kg of milk, which was greater than the HJ (9,129±230 kg), the JH (9,384±190 kg), and the JJ (7,080±240 kg). Milk production in lactation 2 (9,676±163 kg) was greater than that in lactation 1 (8,294±160 kg). The JJ (10.3±4.7%) had the highest frequency of mastitis. The chance of getting mastitis for HH (1.1±0.9%) differed from that for HJ (9.4±4.1%), JH (8.1±3.4%), and JJ (10.3±4.7%). Genetic group affected hormones and metabolites, which may partially explain differences in reproductive measures and milk yield.     

Water-, oil-, and soil-repellent treatment of textiles,artificial leather,and leather

Several products are on the market to realize water-, oil-, and soil-repellent properties on textiles or textile-related materials. To make an adequate and fast rating of repellent properties of finished textiles, different drop tests according to AATCC and ISO standards are commonly used. For evaluation of the repellent properties of solid substrates against different liquids often contact angle measurements are performed. The aim of the work presented here is to determine and evaluate the repellent effects gained by the application of three different finishing agents on three different substrates, such as polyester fabric, artificial leather, and leather. The main questions are at that point: It is possible to gain similar repellent effects with the same finishing product applied on different substrates? Do the different testing methods lead to comparable results? Is there a relation to the repellency against everyday consumer products as red wine, ice tea, or coffee? This article should help the reader to evaluate different testing methods and the influence on common substrates.     

卷烟中锂、铬、镍、铜、砷、硒、钼、镉、铊和铅含量分析

采用微波消解-电感耦合等离子体质谱法测定了41个牌号烤烟型卷烟和雪茄烟样品烟丝中的锂、铬、镍、铜、砷、硒、钼、镉、铊和铅含量,并按照类型和价位对卷烟中这10种有害元素含量进行了统计分析。结果发现:①卷烟中锂和铜的含量较高,铊的含量很低,铬、镍、镉、铅、砷、硒和钼7种元素的平均含量为0.55～4.42μg/g;②雪茄烟中铬、镍、砷、钼、镉、铊和铅的含量一般高于烤烟型卷烟,而硒元素的含量则相反,但差别较小;烤烟型卷烟中锂和铜的含量与雪茄烟没有显著差异;③高档卷烟中的锂、镍、镉、铊和铬含量较低,而砷、铅的含量较高;不同价位卷烟的铜、硒和钼含量差异不显著。     

Tyrosinase, Laccase, and Peroxidase in Mushrooms (Agaricus, Crimini, Oyster, and Shiitake)

Enzyme assays and electrophoresis were used to monitor the activity of tyrosinase, laccase, and peroxidase in Agaricus bisporus (common cultivated button mushrooms and Crimini mushrooms), Oyster, and Shiitake mushrooms. The three enzymes could be differentiated using specific substrates and inhibitors. Tyrosinase seemed to be the major phenol oxidase in the Agaricus strains, while Oyster and Shiitake mushrooms had much lower levels. Peroxidase activity was low or undetectable in all types examined. Control of enzymatic browning in different mushroom types may depend upon the distribution of different oxidases within any given type.     

Polyphenols, Anthocyanins, Ascorbic Acid, and Radical Scavenging Activity of Rubus, Ribes, and Aronia

ABSTRACT: Total polyphenols, total anthocyanins, and reduced ascorbic acid were evaluated in berries belonging to the genera Rubus, Ribes, and Aronia by means of spectrophotometric and high-performance liquid chromatography (HPLC) techniques. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the fruit extracts was tested. Total polyphenols ranged from 140.6 to 888.5 mg/100 g fresh weight (FW), total anthocyanins ranged from 22.0 to 460.5 mg/100 g FW, and reduced ascorbic acid ranged from 12.4 to 153.8 mg/ 100 g FW. The average EC50 values for Aronia melanocarpa, Ribes nigrum, Ribes rubrum, Rubus fruticosus, and Rubus idaeus were 1.8, 2.8, 5.3, 6.4, and 8.2 mg FW, respectively. The results indicate that the fruits tested are good sources of natural antioxidants.     

Simultaneous and Direct Determination of As, Bi, Pb, Sb, and Se and Co, Cr, Cu, Fe, and Mn in Milk by Electrothermal Atomic Absorption Spectrometry

Tungsten permanent modifier with coinjection of Pd(NO₃)₂ and W–Ru permanent modifiers are proposed for the direct and simultaneous determination of As, Bi, Pb, Sb, and Se (group 1) and Co, Cr, Cu, Fe, and Mn (group 2), respectively, in milk by graphite furnace atomic absorption spectrometry. The performance of modifiers was evaluated by means of thermal behavior of analytes, sensitivity, atomic signal profile, repeatability, graphite tube lifetime, and background intensity. An air-assisted pyrolysis step was necessary to quantitative elimination of the organic matter. After methods optimization, 14 commercial milk samples were analyzed. The found concentrations of As, Bi, Pb, Sb, Se, Co, and Cr were lower than their limit of detection (2.13, 2.21, 1.49, 1.63, 2.05, 1.0, and 1.2 μg L⁻¹, respectively). Concentrations of Cu, Fe, and Mn were in the 1.58–5.74 μg L⁻¹, 9.79–49.3 μg L⁻¹, and 2.25–4.08 μg L⁻¹ intervals, respectively. The limits of detection for Cu, Fe, and Mn were 1.7, 5.3, and 2.0 μg L⁻¹, respectively. The accuracy of methods was checked after analysis of two milk standard materials. Results for Cr, Cu, Fe, Mn, Pb, and Mn were in agreement with certified values of SRMs at the 95% confidence level. Accuracy was also evaluated by addition–recovery tests and recoveries in the 86–127% range were obtained for all elements. The use of pretreat platform of graphite tubes with W or W–Ru allowed enlarging the lifetime of atomizer in 750 heating cycles.     

Capsicum--production, technology, chemistry, and quality. Part V. Impact on physiology, pharmacology, nutrition, and metabolism; structure, pungency, pain, and desensitization sequences

The spice Capsicum is the fruit of the cultivated species of the genus Capsicum (family, Solanaceae), C. annuum principally, and C. frutescens L. to a lesser extent. A third variety of C. annuum var. annuum fruits, the large-sized, fleshy bell capsicum is used as a fresh vegetable and valued for its aroma, color, and crisp texture, but with no pungency. This variety is not considered in this series of reviews covering primary processing, production, international trade, chemistry, and biochemistry of functional components--the red keto carotenoids, the aromatic volatiles and the pungent capsaicinoids in Parts I to III. The valid qualitative aspects correlating the specific components of capsicum and their sensory responses are critically covered in Part IV. In this the concluding part of the series of reviews, the significant preference of the spice for initially evoking an aversive response, its potent physiological and pharmacological effects, and the aspects of structure-activity relationships of the pungent stimuli of the capsaicinoids are reviewed. The beneficial effects particularly associated with long usage by some ethnic groups and its safe consumption levels, with a critical review of the studies on the gastrointestinal tract, the cardiovascular system, the sensory system, thermoregulation, nutritional impacts, and an overview of the five series is also detailed.