Determination of green,blue and yellow artificial food colorants and their abuse in herb-coloured green Easter beers on tap

Beer is one of the most popular alcoholic beverages worldwide. For consumer acceptance, significant factors are its taste, flavour and colour. This study determines selected synthetic green, blue and yellow food colorants in popular Easter herb-coloured green beers on tap produced in breweries on Holy Thursday. The abuse of beer colouring with Tartrazine (E 102), Quinoline yellow (E 104), Sunset yellow (E 110), Patent blue (E 131), Indigo carmine (E 132), Brilliant blue FCF (E 133), Green S (E 142) and Fast green FCF (E 143) was assessed in 11 green beer samples purchased in local restaurants. HPLC was used for the separation and detection of artificial colorants with diode-array detection and a Chromolith Performance CN 100 × 4.6 mm column with guard pre-column Chromolith CN 5 × 4.6 mm. Separation was performed in gradient elution with mobile phase containing methanol–aqueous 2% ammonium acetate at pH 7.0. The study showed that eight beers (70%) marketed in the Czech Republic contained artificial colorants (Tartrazine and Brilliant blue FCF). The concentration of colorants found in analysed green herb-coloured beers ranged from 1.58 to 3.49 mg l^–1 for Tartrazine, 0.45–2.18 mg l^–1 for Brilliant blue, while Indigo carmine was detected only once at concentration 2.36 mg l^–1. Only three beers showed no addition of the synthetic colorants. However, the levels of artificial colorants found in beers marketed in the Czech region were very low and did not show a serious risk for consumers’ health.     

双波长比值光谱法测定饮料中的色素

应用双波长比值光谱法测定了果味汽水、水果泡泡中胭脂红、日落黄、酒石黄的含量。依据该3 种色素的比值光谱特征,以日落黄为干扰组分,分别选择431、456nm 和509、525nm 为测定酒石黄和胭脂红的波长;以胭脂红为干扰组分时,选择514、535nm 为测定日落黄的波长。结果显示,酒石黄在0.1～60mg/L、胭脂红在0.2～80mg/L、日落黄在0.8～90mg/L 的质量浓度范围内线性关系良好,平均回收率分别是100.5%、101.1%和102.4%。本方法操作简便、易于推广,可应用于实际样品的检测。     

改性磁性壳聚糖对胭脂红的吸附性能评价

以纳米Fe₃O₄、壳聚糖为材料,采用反相悬浮交联法,用三乙胺做改性剂制备改性磁性壳聚糖,研究其对胭脂红色素的吸附性能影响,考察时间、pH、温度及胭脂红的初始浓度等四个因素对改性磁性壳聚糖吸附胭脂红溶液吸附效果的影响,并对吸附动力学模型、吸附等温模型、吸附热力学和吸附再生性能进行初步探讨。结果表明,当pH=3,吸附时间为270 min,温度为50℃,初始浓度为100 mg/L时,改性磁性壳聚糖对胭脂红溶液的吸附率达到最高,为96.72%。改性磁性壳聚糖对胭脂红溶液的吸附动力学数据符合准二级动力学模型,吸附等温线数据符合Langmuir模型,热力学数据拟合得出ΔH>0,ΔS>0,ΔG<0,得出此反应是吸热反应。经过三次吸附-解析实验,吸附率和解析率仍在40%以上。     

Survey of benzoic acid in cheeses: contribution to the estimation of an admissible maximum limit

Benzoic acid and its salts are commonly used additives in the food industry. Their use is not allowed in dairy products even though they can be found naturally. In this work, 100 cheese samples were tested to establish the maximum concentration that can be considered as “natural” and, therefore, permitted in cheeses. Analyses were carried out by a validated ion chromatography method and “positive” samples were confirmed by two other HPLC methods. Benzoic acid concentrations higher than the method LOQ (8.8?mg?kg^?1) were found in 18 samples, ranging from 11.3 to 28.7?mg?kg^?1, with a mean value of 20.5?mg?kg^?1. Taking into account the distribution of benzoic acid concentrations observed in “positive” samples, it is plausible to estimate a maximum admissible limit of 40.0?mg?kg^?1 for benzoic acid in cheese. Below this value, samples can be considered “compliant”.     

毛细管区带电泳法测定食品中山梨酸、苯甲酸和糖精的含量

采用毛细管区带电泳(CZE),以10mmol/L硼砂和0.1%草酸(pH8.26)为缓冲液,分离电压20kV,检测波长230nm,压差进样时间10s,以焦性没食子酸为内标,在7min内分离和测定了食品中山梨酸、苯甲酸和糖精的含量。线性范围:山梨酸4～640mg/L、苯甲酸4～640mg/L、糖精4～1000mg/L;样品加标回收率在95.0%～98.4%,相对标准偏差(RSD)均小于4%。方法简便、快速、准确。     

Detection of 4-aminocarminic acid in beverages and cake glaze from the German market: a food additive not approved in the EU

In the European Union, carminic acid and its ammonium, calcium, potassium or sodium salts and its aluminium lakes are approved as food additive E120. In beverages obtained from the German market 4-aminocarminic acid (“acid-stable carmine”) was detected by HPLC–PDA and LC–MS/MS. Isolation of the colorant from a liquid dye preparation used for the production of a beverage sample and subsequent NMR analysis confirmed the presence of 4-aminocarminic acid. Synthesis of ¹⁵N-4-aminocarminic acid clearly demonstrated that “acid-stable carmine” is not the ammonium salt of carminic acid, which is approved as food additive in the European Union. In fact, nitrogen in “acid-stable carmine” is covalently bound. The molecular structure of carminic acid is chemically modified and 4-aminocarminic acid does not comply with the specifications laid down for E120 in Commission Regulation (EU) No 231/2012. 4-Aminocarminic acid was also detected in the red-colored glaze of a raspberry cake and in the liquid dye preparation used for coloring this glaze.     

Determination of melamine and its analogues in egg by gas chromatography-tandem mass spectrometry using an isotope dilution technique

A method was developed for the simultaneous determination of melamine, ammeline, ammelide, and cyanuric acid in egg using gas chromatography-tandem mass spectrometry (GC-MS/MS). The samples were first extracted by the solution of diethylamine–water–acetonitrile (10:40:50, v/v/v). Clean-up employed an ‘On Guard II’ RP cartridge, and the dried elute was derivatised using bis-(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane (TMCS). Derivatised samples were analysed by GC-MS/MS using multiple-reaction monitoring (MRM) with ¹³C₃-¹⁵N₃-labelled melamine and cyanuric acid as internal standards. Blank samples of egg were spiked with the four analytes at concentration level of 0.1, 0.5, 1.0 mg kg^?1, and the intra-day and inter-day recoveries were in the range 75.7–122.5% with the relative standard deviation (RSD) from 2.6% to 22.8%. Decision limits (CCα, α = 0.01) for melamine, ammeline, ammelide, and cyanuric acid in egg samples and milk powder were 3.5–5.9 and 2.5 to 3.8 µg kg^?1, and the detection capabilities (CCβ, β = 0.05) were 4.9–8.4 and 3.6–9.5 µg kg^?1, respectively. The method was successfully applied to egg samples and milk products as well. Satisfactory results were obtained as part of the 2009 European Union melamine proficiency test.     

胭脂萝卜酱的研制

研究了一种胭脂萝卜酱的加工工艺,并对胭脂萝卜酱的打浆和调配工艺进行了优化。在单因素实验的基础上,通过正交实验确定葛根打浆的最佳工艺和胭脂萝卜酱的最佳配方。实验结果表明,胭脂萝卜的较佳打浆条件是:匀浆速度8000r/min,匀浆时间3min;葛根的最佳打浆条件是:葛根在料水比为1∶1.2,匀浆速度为9000r/min,打浆时间为3min。胭脂萝卜酱的最佳配方为:复合料比为13∶7,白砂糖50%,柠檬酸0.2%,食盐0.8%,黄原胶0.3%。制得胭脂萝卜酱可溶固形物含量为48%,总酸为0.15%,总糖含量为40.3%。      

高效液相色谱法同时测定食品中18种食品添加剂

建立高效液相色谱同时测定食品中18种食品添加剂的高通量分析方法。对于不含油脂或油脂含量低的样品采用含抗坏血酸棕榈酸酯的正己烷饱和乙腈-6mol/L HCl溶液-饱和氯化钠混合溶液一次提取净化,对于油脂样品采用含抗坏血酸棕榈酸酯的正己烷饱和乙腈-乙腈饱和正己烷液液萃取。采用Ecosil C18色谱柱(250mm×4.6mm,5μm),乙腈-0.6%乙酸溶液作为流动相,梯度洗脱,用紫外检测器检测,检测波长280nm,外标法峰面积定量。18种食品添加剂在1.0～25mg/L范围内线性良好,相关系数r均大于0.99,样品在10、25mg/kg和50mg/kg三个添加水平的平均回收率为88.9%～99.9%之间,相对标准偏差为2.43%～11.7%(n=6),方法的定量限为10mg/kg。方法简便、准确,适用于食品中18种食品添加剂高通量的检测。     

Sensitive determination of cadmium in brown rice and spinach by flame atomic absorption spectrometry with solid-phase extraction

A sensitive flame atomic absorption spectrometry (FAAS) method was developed for the determination of cadmium (Cd) in brown rice and spinach. The method involves extraction with 1?M hydrochloric acid (HCl), followed by a selective pre-concentration by solid-phase extraction (SPE). The pH of the loading sample solution was adjusted to 4.0 for the brown rice and to 5.0 for the spinach. The masking agents, tartrate and citrate, were required for the spinach before pH adjustment. The SPE step achieved a 20-fold enrichment of the sample solution. The limits of quantification (LOQs) were 0.0054?mg?kg^?1 for the brown rice and 0.0022?mg?kg^?1 for the spinach, being more sensitive than those of AOAC Official method 999.10. A single-laboratory validation was performed by testing spiked samples at 0.04 and 0.08?mg?kg^?1 for the brown rice, and 0.02 and 0.04?mg?kg^?1 for the spinach. The average recoveries were 93.3–96.9% with relative standard deviations (RSDs) of 4.1–8.2% for brown rice, and 90.5–91.9% with RSDs of 5.8–10.0% for spinach.     

Simultaneous Determination of 11 Food Additives by Micellar Electrokinetic Capillary Chromatography

A micellar electrokinetic chromatographic (MEKC) method was developed for simultaneous determination of 11 food additives which are commonly used in beverage, yogurt, and candied fruit samples. An uncoated fused-silica capillary with 50 μm i.d. and 70 cm total length (effective length: 60 cm) was used for the separation. The separation buffer consisted of 20 mmol/L sodium tetraborate, 42 mmol/L boric acid (pH 8.83), and 100 mmol/L sodium deoxycholate. The separation voltage was 23 kV, and the detection wavelength was 214 nm. The limits of detection were in the ranges of 0.25 to 2.5 mg/L. The corrected peak areas (Ac) and the concentrations of the 11 additives showed linear relationships within the ranges of 0.6–400 mg/L with linear correlation coefficients (r) above 0.99. The recoveries ranging from 81.6 to 115.0 % with relative standard deviations (RSDs) all lower than 5 % were obtained, which demonstrated the accuracy of the proposed method. A Food Analysis Performance Assessment Scheme (FAPAS®) proficiency test sample was analyzed. The results showed that the current method with simple sample pretreatment could meet the needs for routine analysis of the 11 additives in beverage, yogurt, and candied fruit samples.     

Naturally occurring benzoic,sorbic, and propionic acid in vegetables

ABSTRACT

Benzoic, sorbic and propionic acid are used as preservatives in foods and can also be naturally present in processed foods. The levels of preservatives in 939 vegetables were determined. Benzoic and sorbic acid were analysed by high-performance liquid chromatography with a diode-array detector and further confirmed by liquid chromatography-tandem mass spectrometry, whereas propionic acid was analysed using a gas chromatography-flame ionization detector and further confirmed by gas chromatography-mass spectrometry. Benzoic and propionic acid were found in 10.9% and 36.2%, respectively, of the samples. In contrast, sorbic acid was not found in any of the samples. The highest amounts of benzoic and propionic acid were found in perilla leaves (0.33?298 mg kg^–1) and ginseng (<LOD?32.8 mg kg^–1), respectively. The background concentration ranges of naturally occurring preservatives in vegetables determined in this study could be used for inspection services of standard criteria to address consumer complaints or trade disputes.     

反相高效液相色谱法同时测定九种食品添加剂

采用反相高效液相色谱法,一次进样,同时测定食品中常见的9种食品添加剂:苯甲酸、山梨酸、糖精钠、安赛密、柠檬黄、日落黄、胭脂红、苋菜红、咖啡因。实验采用Nova-PakC18柱(3.9mm×150mm,4μm,Waters)为分离柱,以20mmol/L乙酸铵(pH6.8)-甲醇为流动相(梯度洗脱:甲醇:5%5min;5%～30%,12.5%/min;30%继续3min;30%～5%,25%/min),采用紫外检测器在234nm下进行检测。整个分析过程在10min内完成。其平均加标回收率为77.0%～108.5%,相对标准偏差小于5%。该方法结果准确,适用于食品常规质量检测。     

Glyphosate residues in Swiss market foods: monitoring and risk evaluation

A total of 243 samples of diverse foodstuffs were analysed for glyphosate and aminomethylphosphonic acid (AMPA) using a liquid chromatography triple quadrupole mass spectrometry (LC/MS/MS) method with a relatively low limit of quantification in the range of 0.0005–0.0025 mg kg^?1. Main contributors for dietary glyphosate and AMPA intake were cereals and pulses. The results suggest that pasta is a very important foodstuff for dietary glyphosate residue intake in Switzerland. Interestingly all samples of wine, fruit juice and nearly all samples of honey tested positive for glyphosate although at very low levels. A dietary risk assessment was conducted. Food products for analysis were not selected purely at random, rather products were selected for which high levels of glyphosate residues were suspected. However, even in samples where high residue levels were expected, no exceedances of maximum residue levels were found. Consequently, human exposure did not exceed neither acceptable daily intake nor acute reference dose. Therefore, glyphosate residues found in the sampled foodstuffs from the Swiss market were of no concern for human health.     

Migration of bisphenol A from polycarbonate baby bottles purchased in the Spanish market by liquid chromatography and fluorescence detection

During the last decade the safety of bisphenol A (BPA) monomer in polycarbonate baby bottles has drawn the attention of both the public and the scientific community. This paper presents the results of BPA migration from polycarbonate baby bottles bought in the Spanish market, into simulant B (3% acetic acid), 50% ethanol and into real food (reconstituted infant formula). Furthermore, it was also the objective of this study to assess the suitability of 50% ethanol as a simulant for infant formula. BPA was analysed by a multi-analyte liquid chromatography method with fluorescence detection and mass spectrometry confirmation. The method was in-house validated and accredited by the national accreditation body. The validation results for this analyte in the previous mentioned matrices were: LOD?=?0.004–0.007?mg?kg^–1; LOQ (validated)?=?0.03?mg?kg^–1; RSD%?=?3.4–5.8; and recovery?=?106.6–118.2%. A collection of 72 different baby bottle samples from 12 different brands were analysed. Baby bottle material was identified by FTIR. The migration test conditions used were those recommended for baby bottles in the Guidelines on testing conditions for articles in contact with foodstuffs (with a focus on kitchenware), prepared by the European network of laboratories for food-contact materials. In most of the migration assays the results were below the LOD. In four of the commercial brands there was detectable migration into the simulant 50% ethanol and BPA was detected in only two samples of infant formula (0.01?mg?kg^–1). Migration results obtained were in compliance with European Union regulations.     

Liquid chromatography-tandem mass spectrometry method for the determination of anthelmintics in alfalfa plants

A simple and inexpensive liquid chromatography-tandem mass spectrometric method for the determination of anthelmintics in alfalfa plants (Medicago sativa L.) was developed and validated. Anthelmintics in plant leaves and stems (green chops) were extracted with methanol/acetonitrile (7:3, v/v) followed by a concentration and clean-up step using solid-phase extraction (Strata-X, 500?mg, 6?ml cartridge). After drying with nitrogen gas, the adsorbed analytes were eluted with methanol/acetonitrile (50:50, v/v) mixture followed by 100% acetonitrile. Chromatographic separation was achieved on an Atlantis T-3 (2.1?×?100?mm?×?3?µm) analytical column with a Phenomenex guard cartridge (C8, 4?×?3?mm) attached to a Waters triple quadrupole mass spectrometer operated in positive electrospray ionisation mode with selected reaction monitoring. Samples were analysed using gradient elution at a flow rate of 0.35?ml?min^–1. The mobile phase consisted of a 10?mM ammonium formate solution in (A) water/acetonitrile (90:10, v/v) and (B) methanol/acetonitrile (50:50, v/v). The method was validated for levamisole, fenbendazole, fenbendazole sulphoxide and fenbendazole sulphone at 10, 20 and 40?µg?kg^–1 and for eprinomectin at 20, 40 and 80?µg?kg^–1. Limits of quantification (LOQ) were 10?µg?kg^–1 for all analytes except eprinomectin, which had an LOQ of 20?µg?kg^–1. The overall mean recovery in green plants was between 74.2% and 81.4% with repeatabilities ranging from 2.2% to 19.1% and reproducibilities in the range 3.8–8.7%. The validated method was applied to plant samples in a study on the behaviour of anthelmintic drugs in a soil, plant and water system.     

Dietary exposure to aluminium of the Hong Kong population

A total of 256 individual food samples were collected in Hong Kong for aluminium testing. Most of food samples were analysed in ready-to-eat form. High aluminium levels were found in steamed bread/bun/cake (mean: 100–320 mg kg^?1), some bakery products such as muffin, pancake/waffle, coconut tart and cake (mean: 250, 160, 120 and 91 mg kg^?1, respectively), and jellyfish (ready-to-eat form) (mean: 1200 mg kg^?1). The results demonstrated that aluminium-containing food additives have been widely used in these food products. The average dietary exposure to aluminium for a 60 kg adult was estimated to be 0.60 mg kg^?1 bw week^?1, which amounted to 60% of the new PTWI established by JECFA. The main dietary source was “steamed bread/bun/cake”, which contributed to 60% of the total exposure, followed by “bakery products” and “jellyfish”, which contributed to 23 and 10% of the total exposure, respectively. However, the estimation did not include the intake of aluminium from natural food sources, food contact materials or other sources (e.g. drinking water). Although the results indicated that aluminium it is unlikely to cause adverse health effect for the general population, the risk to some populations who regularly consume foods with aluminium-containing food additives cannot be ruled out.     

蛋白酶胭脂虫天然染料的提取及羊毛织物染色性能研究

利用蛋白酶对胭脂虫干体内的胭脂红酸进行萃取,通过天然染料胭脂虫色素对羊毛织物进行染色.利用蛋白酶进行色素提取,具有温度低、萃取时间短、提取效果好等特点.实验确定提取工艺为:蛋白酶浓度1％,50℃搅拌60 min,调pH值为4,升温至90℃,搅拌60 min.通过对上染工艺中的胭脂虫红色素浓度、染色温度、染色时间、pH值等影响因素进行单因素实验分析,得到了最佳的染色工艺:胭脂虫红色素浓度60％,pH值4,染色温度90℃,染色时间50 min,浴比1:40.     

Using capillary isotachophoresis for the determination of biogenic amines and D‐isocitric acid in food products

This paper presents results achieved in the determination of biogenic amines in various food products and quality evaluation of some commercial orange juices by capillary isotachophoresis. The highest amount of histamine was determined in frankfurters (146.75 mg·kg^–1); the content of tyramine was either under detection limit of method or it was present in very low concentrations. The highest amount of cadaverine was determined in Kari?ka cheese (666.36 mg·kg^–1). The limit of determination was 1.59 mg·kg^–1 for histamine and 1.25 mg·kg^–1 for tyramine. The recovery of method ranged from 95.4 to 104.9%. Surprisingly it was found that many organge juice samples did not reach required values according to the Code of Practice. The lowest ratio of citric to D ‐isocitric acids was found in Happy day juice (44.1). Limit of determination was 1.62 mg·dm^–3 for citric acid and 2.00 mg·dm^–3 for D ‐isocitric acid. The recovery of the method ranged from 89 to 96.5%.     

2012~2015年贵州省餐饮食品中色素检测结果分析

目的 对贵州省餐饮服务食品中柠檬黄、诱惑红、日落黄、胭脂红和苏丹红5种色素进行检测与分析, 掌握我省餐饮食品安全状况。方法 根据GB/T 5009.35-2003《食品中合成着色剂的测定》, SNT 1743-2006《食品中诱惑红、酸性红、亮蓝、日落黄的含量检测 高效液相色谱法》和GB/T 19681-2005《食品中苏丹红染料的检测方法 高效液相色谱法》, 对2012~2015年贵州省餐饮服务食品中5种色素进行检测, 按GB/2760-2011《食品添加剂使用卫生标准》和《食品中可能违法添加非食用物质名单》判断是否合格。结果 3054批食品中, 柠檬黄、诱惑红、日落黄、胭脂红和苏丹红的合格率分别为95.6%、99.1%、98.5%、99.3%和100%。结论 贵州省4年内餐饮服务食品中色素的总体安全状况较好。