Identification of C-glycoside flavonoids as potential mutagenic compounds in kava

ABSTRACT:  Kava ( Piper methysticum ) extract products have been implicated in a number of severe hepatotoxicity cases. However, systematic toxicological studies regarding kava consumption have not been reported. In this study, 6 major kavalactones and different solvent fractions of kava roots, leaves, and stem peelings were evaluated for their mutagenic potential. None of the kavalactones was found to be positive in the experimental concentration ranges tested by the umu test (a sensitive test for point mutations). However, among the different solvent fractions, the n -butanol fraction of kava leaves was positive. Further investigations using bioassay-directed isolation and analysis indicated that 2 C -glycoside flavonoid compounds accounted for the positive mutagenic results. Two isolated compounds were identified as 2"- O -rhamnosylvitexin and schaftoside by NMR and MS techniques.     

Investigation of food products containing garlic or onion for a false positive sulphite response by LC-MS/MS

ABSTRACT

In the US, sulphites must be declared on the label if they are present in concentrations greater than 10 mg/kg (determined as) SO₂ because an allergic-like response has been reported in a small subset of the population upon consumption of sulphite-containing products. The most widely used method for sulphite determination, the optimised Monier-Williams (OMW), produces false positive results with vegetables from the Allium (garlic) and Brassica (cabbage) genera due to extraction conditions that are thought to cause endogenous sulphur compounds to release SO₂. Recently, an LC-MS/MS method was developed for sulphites but has only been tested with samples that are 100% Allium or Brassica. Since regulatory samples may contain these vegetables as ingredients, additional investigations were necessary to determine the potential extent of false positives. Four blank matrices, chips, phyllo shells, hummus, and quinoa were spiked with various concentrations of onion and garlic powders. The sulphite concentrations were determined using an LC-MS/MS method. The matrix is extracted with a buffered formaldehyde solution, converting free and reversibly bound sulphite to the stable formaldehyde adduct, hydroxymethylsulfonate (HMS). It was determined that even at concentrations up to 8% garlic powder or 2% onion powder, the measured sulphite concentration was below the 10 mg/kg SO₂ labelling threshold. Commercial dried garlic powders were evaluated to determine the variation in responses that might be encountered in future regulatory samples. Recovery studies were conducted to determine if these methods would detect added sulphite. The ability to eliminate false positives due to these ingredients will result in a greater reliability in the accurate determination of added sulphite to ensure compliance with labelling requirements.     

Assessment of Kavalactones in Kava Beverage Products and Aqueous Infusions

ABSTRACT:  Kava ( Piper methysticum Forst. f.  ) is traditionally used as a beverage for relaxation in social occasions in South Pacific islands. This study was conducted to develop analytical methods for assessing kavalactone content in functional beverage products containing kava, as well as beverages prepared from kava roots by a traditional method involving infusion (mild extraction) with water. Samples of fruit-flavored beverages were prepared by solid-phase or liquid–liquid extraction to remove interfering substances and the major kavalactones (methysticin, dihydromethysticin, kavain, dihydrokavain, yangonin, and desmethoxyyangonin) were separated and identified by GC-FID and GC/EI-MS. A difference in kavalactone content was observed between the 2 commercial beverage products (37.03 compared with 0.044 mg per serving in 240 mL). Kava beverages prepared fresh by water infusion contained much higher levels of kavalactones than the commercial products as determined by a high-performance liquid chromatographic procedure. The results also demonstrated the isomerization of yangonin (Y) in an acidic aqueous solution with exposure to light, with the presence of cis -Y in a fruit-flavored beverage containing kava. The implications of the isomerization of Y on quality and safety aspects have yet to be evaluated. The analytical methods developed in this study are potentially applicable to kavalactone analysis in various nonalcoholic, noncarbonated beverages.     

LC-MS/MS法测定保健食品中左卡尼汀的含量

目的 建立保健品中左卡尼汀的LC-MS/MS的测定方法。方法 待测样品经超声提取、稀释后, 分别采用CAPCELL PAK CR色谱柱和PC HILIC色谱柱进行分离, 最后用LC-MS/MS进行检测。 结果 使用CAPCELL PAK CR法检测左卡尼汀能够得到更高的灵敏度, 线性范围为0~200 ng/mL, 相关系数为r=0.9995。结论 该方法灵敏度高、准确、重现性好, 可以用于一些保健食品中左卡尼汀的含量检测。     

LC-MS/MS analysis of bisphenol S and five other bisphenols in total diet food samples

ABSTRACT

It is already known that bisphenol S (BPS) has been used as a substitute for BPA in thermal papers in recent years. It is not clear, however, if BPS has also been used to replace BPA in can coatings as currently being speculated due to a lack of credible studies on migration of BPS from can coatings and occurrence data of BPS in foods. In this study, an LC-MS/MS method was developed for the analysis of BPS, along with several other bisphenols, and method detection limits for BPS varied from 0.0017 to 3.1 ng/g depending on the type of sample matrix and the amount of sample analysed. This method was used to analyse 159 different food composite samples from a recent Canadian total diet study. Bisphenol E (BPE), bisphenol B (BPB), and bisphenol AF (BPAF) were not detected in any of the 159 food composite samples, bisphenol F (BPF) was detected in only three samples (25–2360 ng/g), and bisphenol A (BPA) was detected in 10 samples (5.3–41 ng/g) which were all prepared from canned foods. BPS was not detected in any of the canned food composite samples but was detected in nine food composite samples prepared from meat and meat products (1.2–35 ng/g), indicating sources for BPS other than can coatings may be possible, which will be investigated in future studies.     

Influence of food condiments on the formation of carcinogenic heterocyclic amines in cooked chicken and determination by LC-MS/MS

Heterocyclic amines (HCAs) are known to be suspected human carcinogens produced by high-temperature cooking of protein-rich foods such as meat and fish. In the present study, the influence of numerous food condiments on the formation of HCAs in cooked chicken was investigated. Chicken samples were subjected to pan-frying under controlled temperature. The levels of HCAs DMIP, MeIQx, 4,8-DiMeIQx, PhIP, harman and norharman were found to be between 0.93 and 27.52 ng g^?1, whereas IQ, MeIQ, AαC, MeAαC, Trp-P-1 and Trp-P-2 were found either below the limit of quantification or not detected in the control sample. Nevertheless, for samples cooked using food condiments, the amounts of HCAs (DMIP, MeIQx, 4,8-DiMeIQx and PhIP) were between 0.14 and 19.57 ng g^?1; harman and norharman were detected at higher concentrations up to 17.77 ng g^?1 while IQ and MeIQ were at levels below the limit of quantification; and AαC, MeAαC, Trp-P-1 and Trp-P-2 were not detected in any of the samples. The outcomes revealed that the formation of HCAs (except harman and norharman) diminished after the addition of food condiments. Edible oil contributed to the highest levels of HCA formation, followed by garlic, paprika, pepper and tomato.     

液质联用快速鉴定减肥类保健食品中4种违禁添加药物

目的建立快速鉴定减肥类保健食品中咖啡因、盐酸麻黄碱、盐酸芬氟拉明和盐酸西布曲明的液质联用方法。方法使用Agilent 1100液相色谱和离子阱质谱联用,ESI源,C18柱梯度洗脱。结果使用本方法对12种市售减肥保健食品中的4种违禁添加药物进行了快速筛查鉴定,其中2种检出西布曲明。结论方法简便快速,专属性好。     

Screening of veterinary drug residues in food by LC-MS/MS. Background and challenges

Regulatory agencies and government authorities have established maximum residue limits (MRL) in various food matrices of animal origin for supporting governments and food operators in the monitoring of veterinary drug residues in the food chain, and ultimately in the consumer’s plate. Today, about 200 veterinary drug residues from several families, mainly with antibiotic, antiparasitic or antiinflammatory activities, are regulated in a variety of food matrices such as milk, meat or egg. This article provides a review of the regulatory framework in milk and muscle including data from Codex Alimentarius, Europe, the U.S.A., Canada and China for about 220 veterinary drugs. The article also provides a comprehensive overview of the challenge for food control, and emphasizes the pivotal role of liquid chromatography-mass spectrometry (LC-MS), either in tandem with quadrupoles (LC-MS/MS) or high resolution MS (LC-HRMS), for ensuring an adequate consumer protection combined with an affordable cost. The capability of a streamlined LC-MS/MS platform for screening 152 veterinary drug residues in a broad range of raw materials and finished products is highlighted in a production line perspective. The rationale for a suite of four methods intended to achieve appropriate performance in terms of scope and sensitivity is presented. Overall, the platform encompasses one stream for the determination of 105 compounds in a run (based on acidic QuEChERS-like), plus two streams for 23 β-lactams (alkaline QuEChERS-like) and 10 tetracyclines (low-temperature partitioning), respectively, and a dedicated stream for 14 aminoglycosides (molecularly-imprinted polymer).     

市售食品快速检测产品的应用评价与分析

目的评价分析市售食品快速检测产品的适用性。方法应用12种快检仪器、32种快检试纸条(卡)和试剂盒对6个区域采集的13763件样品进行检测,并抽取部分样品进行实验室结果比对。总结快检操作中存在的问题,并进行分析。结果本次评价的44种产品中,5种产品检测结果准确率达100%;5种产品检测结果存在假阴性;14种产品检测结果存在假阳性,其中8种产品未能检出超标样品。部分产品存在操作复杂、效率较低、成本较高等问题。结论综合考虑产品检测准确性及适用性等方面问题,44种产品中10种产品能够基本满足基层食品快检需要,其中A5、E19、E20、F7等4种产品具有较好的推广应用价值,B2、B3、B4、D3、E2、F6等6种产品需进一步改进完善。     

Oligomers in polyethylene furanoate - identification and quantification approach via LC-UV LC-MS response ratio

ABSTRACT

Polyethylene furanoate polymer is intended to be used as a food contact material. A PEF polymer sample was investigated for its oligomer composition by solvent extraction and using HRLC-MS. The 20 oligomers found were divided into four groups: group I contains cyclic oligomers consisting of furandicarboxylic acid and monoethylene glycol units, group II comprises cyclic oligomers consisting of furandicarboxylic acid, monoethylene glycol units and one diethylene glycol unit, group III are cyclic oligomers were two monoethylene glycol units are substituted by diethylene glycol units and group IV are linear oligomers consisting of furandicarboxylic acid and monoethylene glycol units. Oligomers of group I account for around 87% of the total oligomer content, group II oligomers 12% and group III oligomers 1%. The contribution of group IV oligomers is very small: less than 0.05%. MS-MS experiments showed similar fragmentation patterns for all oligomers. The results of this study demonstrate that oligomers are abundant in the PEF material and are potential migrants to foods that are in contact with the polymer. Oligomers of group I and group II have the same absorption maxima in UV detection which was used to develop a quantification approach for these oligomers using dimethyl 2,5-furandicarboxylate as external standard.     

N-nitrosamines migrating from food contact materials into food simulants: analysis and quantification by means of HPLC-APCI-MS/MS

It was the aim of the work described here to develop a validated analytical method for the determination of N-nitrosamines in food simulants. Here, we present the validation of a liquid chromatography–atmospheric pressure chemical ionisation–tandem mass spectrometry method for the determination of 13 N-nitrosamines in the food simulants deionised water, 3% acetic acid and 10% ethanol. Method validation encompassed linearity, LOD, LOQ, recovery, precision and stability of the N-nitrosamines. The method was found to be sufficiently rugged and suitable for routine analysis. In addition, the developed method is on average 10 times more sensitive than the gas chromatography–thermal energy analyser (GC-TEA) method that is currently stipulated in Recommendation XXI for commodities based on natural and synthetic rubber issued by the German Federal Institute for Risk Assessment (BfR). The developed method was applied to determine the N-nitrosamine contents in migration solutions of 12 elastomer samples covering a range of different elastomer types. In 10 out of 12 samples, N-nitrosamines were determined. In most samples, the guidance value of 1 µg/dm² specified in BfR Recommendation XXI was not exceeded. In conclusion, the analytical method presented here offers a useful alternative to the GC-TEA method currently stipulated in BfR Recommendation XXI. This is of wider relevance, since BfR recommendations are used for compliance assessment of Article 3, paragraph 1 a of the Regulation (EC) No. 1935/2004 with respect to their health safety.     

市售18种食品中克伦特罗快速检测产品的测试评价与分析

目的筛选出可用于监管的克伦特罗快速检测产品。方法以猪肉为基质,采用基质加标的方式制备盲样,使用18个厂家的克伦特罗快速检测产品进行测试,以测试结果的检出限、灵敏度、特异性、假阴性率、假阳性率为性能指标,同时考察方法的实效性,前处理的便捷性进行综合评价。结果本次评价的18种产品中,有3种产品的各项性能指标能够符合性能指标技术规范要求。结论综合考虑产品性能指标符合情况和适用性等方面,3种快速检测产品可满足食品快检监管需要,其他产品需进一步改进技术及规范应用。     

Validation and application of an LC-MS/MS method for the determination of cyclic oligomers originating from polyamide 6 and polyamide 66 in food simulant

Polyamides (PAs) are used in the production of various food contact materials (FCMs) and articles such as kitchen utensils and packaging material. Cyclic oligomers have been identified as potential migrants from PA. This study describes the development, validation and application of a multi-oligomer analytical method based on LC-ESI-MS/MS for the identification and quantification of eight cyclic oligomers of PA 6 and four PA 66 migrating from FCMs into food simulant B (3% acetic acid) and beverages. It was proved that doubly charged precursor ions of the cyclic PA 6 and PA 66 oligomers above a mass of 500 Da are formed during the ionisation process of the electrospray technique used. Direct injection of a diluted food simulant into the LC-ESI-MS/MS system after migration makes the validated method a valuable tool for investigating migration of cyclic PA oligomers. The validation results demonstrate that the multi-oligomer method is applicable for the analysis of cyclic PA 6 and PA 66 oligomers in food simulant B. For all investigated cyclic PA oligomers, detection limits were in the range of 0.1–1.1 µg/l. Linearity (r² ≥ 0.99), trueness values between 91% and 122%, and intra-day (RSD_r < 10%) and inter-day precision (RSD_R < 19%) were determined and satisfied validation criteria set out by the European Reference Laboratory for FCMs. The method was extended to tap water and tea. Finally, the multi-oligomer method was successfully applied to determine cyclic PA oligomers in migration solutions originating from different PA FCMs. In all migration solutions, concentrations of cyclic PA oligomers were determined above the LOQ. A preliminary risk assessment based on in silico tools was performed. The results demonstrate the urgent need for toxicological data that would facilitate the evaluation of the health risk of cyclic PA oligomers.     

Monitoring by LC-MS/MS of 48 compounds of sildenafil,tadalafil, vardenafil and their analogues in illicit health food products in the Korean market advertised as enhancing male sexual performance

More than 46 phosphodiesterase type 5 (PDE5) inhibitor analogues have been found to be present as illegal adulterants in various forms of health food products (powder, tablet, capsule, etc.), thereby placing the health of consumers at risk through product intake. In this study, 164 samples advertised to be effective at enhancing male sexual performance were collected over a 4-year period (2009–2012) from the Korean on-line or off-line market and screened. An LC-MS/MS method was employed to screen for the presence of 48 compounds including sildenafil, tadalafil, vardenafil and their analogues. Method validation established LOQs (0.30–10.00 ng ml^?1 or ng g^?1) and recoveries (spiked in liquid sample, 84–112%; spiked in solid sample, 83–110%). Most of the illicit products screened were adulterated with 14 of the PDE5 derivatives under examination, including considerable amounts of sildenafil and tadalafil; of the 48 compounds, tadalafil was the most frequent adulterant (42.6%), followed by sildenafil (27.9%). Specifically, tadalafil concentration ranges (mg g^?1) in the samples collected over the 4-year period were determined as follows: 2.91–52.20 (2009), 4.50–108.10 (2010), 0.37–101.40 (2011), and 0.08–138.69 mg g^?1 (2012). The concentration ranges (mg g^?1) of sildenafil were also at high levels: 4.90–117.96 (2009), 1.30–369.93 (2010), 0.03–241.77 (2011), and 18.34–297.91 mg g^?1 (2012). The results of screening for PDE5 inhibitor pharmaceuticals as adulterants in illicit health food products are of great significance with respect to the protection of public health and consumer safety.     

我国与国际食品法典委员会关于水产品中食品添加剂使用规定的对比分析

本文对GB 2760-2014与CODEX STAN 192-1995, Rev 2019中关于水产品中可使用的食品添加剂规定进行了详细的对比分析。从水产品分类、允许使用的食品添加剂种类、功能与限量等方面比较分析我国与CAC国际标准的异同。探讨了我国水产品中食品添加剂使用过程中存在的问题并提出了具体的对策和建议。     

酶联免疫吸附法及其在食品分析中的应用

简单介绍了酶联免疫吸附法(ELISA),并且就其在食品分析中的应用进行了较详细的评述,主要包括ELISA用于食品微生物、食品中的毒素、残留农药和其他成分的检测。     

水产品中氯霉素快速检测产品的验证性评价及分析

目的评价市售17种氯霉素快速检测产品的性能指标和现场适用性,为基层选择使用该种快检产品提供指导。方法以鱼肉为基质,采用样品加标的方式制备评价用盲样。使用17个厂家的氯霉素快速检测产品进行测试,以测试结果的假阳性率、假阴性率、结果的相对准确度为性能指标,同时考察方法的实效性,前处理的便捷性进行综合评价。结果有10个厂家的快检试剂盒假阳性率为0%,假阴性率为0%,相对准确度100%,1个厂家产品出现较低的假阳性结果 ,可满足监管需要。结论为保证快检结果的准确性和科学性,有必要对该类产品进行评价和分析。     

Antioxidant activity and consumer acceptance of grape seed flour‐containing food products

Grape seed flour (GSF) is produced from the pomace waste generated during winemaking. The inclusion of Merlot and Cabernet Sauvignon GSFs in cereal bars, pancakes and noodles was evaluated using antioxidant activity measurements [2,2 diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging]. Each product (noodles, pancakes and cereal bars) was also evaluated on separate days for consumer acceptance (n = 100 per panel). In comparing antioxidant activities, the highest DPPH radical‐scavenging activity was in pancakes containing Cabernet Sauvignon GSF (25% and 30%), noodles containing Cabernet Sauvignon GSF (20%) and cereal bars containing Merlot GSF (5%). From consumer sensory evaluation, cereal bars made with Merlot GSF, control pancakes and control noodles had high consumer acceptance. Products with low consumer acceptance included pancakes containing 25% Cabernet Sauvignon GSF and noodles containing 20% Cabernet Sauvignon GSF. Overall, the cereal bar containing 5% Merlot GSF showed a good balance of high antioxidant activity with consumer acceptability, making this a promising GSF‐containing new food product.     

Development and validation of an LC-MS/MS method for the detection of phomopsin A in lupin and lupin-containing retail food samples from the Netherlands

Phomopsins (PHO) are mycotoxins produced by the fungus Diaporthe toxica (also referred to as Phomopsis leptostromiformis). Lupin is the most important host crop for this fungus and PHO are suspected as cause of lupinosis, a deadly liver disease, in sheep. Lupin is currently in use to replace genetically modified soy in many food products available on the European market. However, a validated method for analysis of PHO is not available until now. In this work, a dilute-and-shoot LC-MS/MS-based method was developed for the quantitative determination and identification of phomopsin A (PHO-A) in lupin and lupin-containing food. The method involved extraction by a mixture of acetonitrile/water/acetic acid (80/20/1 v/v), dilution of the sample in water, and direct injection of the crude extract after centrifugation. The method was validated at 5 and 25 µg PHO-A kg^?1 product. The average recovery and RSD obtained were 79% and 9%, respectively. The LOQ (the lowest level for which adequate recovery and RSD were demonstrated) was 5 µg PHO-A kg^?1. Identification of PHO-A was based on retention time and two transitions (789 > 226 and 789 > 323). Using the average of solvent standards from the sequence as a reference, retention times were all within ± 0.03 min and ion ratios were within ± 12%, which is compliant with European Union requirements. The LOD (S/N = 3 for the least sensitive transition) was 1 µg PHO-A kg^?1 product. Forty-two samples of lupin and lupin-containing food products were collected in 2011–2012 from grocery stores and internet shops in the Netherlands and analysed. In none of the samples was PHO-A detected.     

基于LC-MS和GC-MS结合多元统计的白酒酚类成分分析

采用液相色谱-质谱联用法（LC-MS）和气相色谱-质谱联用法（GC-MS）建立14种酚类化合物的定性定量检测方法,对12种香型38个白酒样品进行检测,并对结果进行多元统计分析。结果表明,在检测范围内各线性相关系数R2≥0.997,检出限为0.62～6.42 μg/L,定量限为1.44～12.25 μg/L,加标回收率为86.50%～104.35%。12种香型白酒酚类化合物的组成和含量有差异,挥发性酚类化合物的种类和含量比不挥发性酚类化合物更多,白酒中含量相对较高的不挥发性和挥发性酚类化合物分别是阿魏酸和4-甲基苯酚。通过聚类分析（CA）对不同白酒的香型进行分类,并用主成分分析（PCA）解析影响各香型白酒分布的特征酚类化合物。白酒中酚类化合物准确的定量测定技术以及结合多元统计分析可为白酒的品质研究提供理论依据。