bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative Analysis of Iron-Containing Protein Myoglobin in Different Foodstuffs by Liquid Chromatography Coupled to High-Resolution Inductively Coupled Plasma Mass Spectrometry
Authors: Harrington Chris F , Elahi Selvarani , Merson Sheila A , Ponnampalavanar Punitha
Published: February 2020

Quantitative determination was made of the iron-containing protein myoglobin in a range of different foods, including meat, processed meat, fish, and shellfish, by liquid chromatography coupled to a double-focusing sector field inductively coupled plasma mass spectrometry (ICP–MS). The concentration of myoglobin determined in the samples ranged from 0 to 6.5 mg/kg, and the analytical precision (coefficient of variation) for the analysis of 8 replicate raw steak extracts was 2.1%. By using a double-focusing ICP–MS instrument, direct on-line detection of the most abundant iron isotope 56Fe was possible without interference from a major polyatomic interference (40Ar16O). Separation of myoglobin from other iron-containing compounds was facilitated by use of a gel filtration column (TSK Gel G2000SW) and Tris buffer (pH 7.2). The chromatographic column was coupled directly to the nebulizer of the ICP–MS instrument by a short piece of PEEK® tubing. To ensure sufficient quality control throughout the study, a raw beefsteak sample was developed as an in-house reference material. The concentration of the heme-iron-containing protein myoglobin in this sample was determined by the developed method and independently by a conventional spectrophotometric method. The agreement between the 2 analytical techniques was very good. The detection limit (3 times the signal/noise ratio for a blank) of the reported method for myoglobin was 0.85 ng Fe/L.
Confirmatory Determination of Six Penicillins in Honey by Liquid Chromatography/Electrospray Ionization–Tandem Mass Spectrometry
Authors: Wang Jian
Published: February 2020

A confirmatory method for 6 penicillin antibiotics (amoxicillin, ampicillin, penicillin G, oxacillin, cloxacillin, and dicloxacillin) in honey is presented that allows determination and confirmation of identity of the antibiotics at trace levels. The method includes the use of a stable isotope-labeled internal standard benzyl (d7-phenyl) penicillate and removal of sugar and other substances by solvent and solid-phase extraction. The honey extracts are then analyzed for penicillin residues by liquid chromatography/electrospray ionization–tandem mass spectrometry. Mass spectral acquisition was achieved in an electrospray positive ion mode by applying multiple reaction monitoring of 2 or 3 fragment ion transitions to provide a high degree of sensitivity and specificity. Typical recoveries of 6 penicillins at fortification levels of 6, 16, 40, and 80 μg/kg ranged from 51.4 to 132.9%. The recoveries varied with the individual penicillins and were affected by different honey matrixes. The ion ratios were consistent and could be used for confirmation of identity of the penicillins. The method limits of detection (μg/kg) were 0.25 for amoxicillin, 0.19 for ampicillin, 0.068 for penicillin G, 0.028 for oxacillin, 0.052 for cloxacillin, and 0.085 for dicloxacillin. The method limits of confirmation (μg/kg) were 0.44 for amoxicillin, 0.52 for ampicillin, 0.23 for penicillin G, 0.14 for oxacillin, 0.14 for cloxacillin, and 0.15 for dicloxacillin when a sample size of 5 g honey was used.
Determination of Tylosin in Feeds by Liquid Chromatography with Solid-Phase Extraction
Authors: Gramse Matthew J , Jacobson Paul E , Selkirk James C
Published: February 2020

A method was developed for the determination of tylosin in feeds. The method involves extraction of tylosin with methanol, concentration under a stream of nitrogen, and cleanup using Phenomenex C18 solid-phase extraction cartridge. Analyte separation and quantitation were achieved by gradient reversed-phase liquid chromatography and UV absorbance at 285 nm with a reference wavelength of 320 nm with column temperature of 45°C. Average spike recoveries for samples prepared at 4 spiking levels (22.7, 181, 907, and 1000 g/ton) were 111.0, 94.9, 96.2, and 98.6%, respectively. The overall method precision at each of the 4 spiking levels was ≤ 7.85% relative standard deviation. The limits of detection and quantitation (g/ton) were 2.16 and 7.20 g/ton, respectively.
Determination of Fluquinconazole, Pyrimethanil, and Clofentezine Residues in Fruits by Liquid Chromatography with Ultraviolet Detection
Authors: Navickiene Sandro , Ribeiro Maria Lúcia
Published: February 2020

A simple method was developed for the determination of fluquinconazole, pyrimethanil, and clofentezine in whole fruit; peel; and pulp of mango, apple, and papaya. These compounds were extracted from fruit samples with a mixture of ethyl acetate-n-hexane (1 + 1, v/v). An aliquot (2 mL) of the extract was evaporated to near dryness under a stream of nitrogen, and the residue was dissolved with 2 mL methanol. The analysis was performed by means of liquid chromatography with ultraviolet detection at 254 nm using a gradient solvent system. The method was validated with fortified fruit samples at concentration levels of 0.05, 0.10, 0.20, and 0.50 mg/kg. Average recoveries (4–8 replicates) ranged from 80 to 95% with relative standard deviations between 3.5 and 12.7%. Detection limits ranged from 0.03 to 0.05 mg/kg for fruit pulp and 0.03 mg/kg for whole fruit. The quantitation limits ranged from 0.05 to 0.10 mg/kg for fruit pulp and 0.05 mg/kg for whole fruit. The analytical method was applied to fruit samples obtained from local markets.
Determination of Plant Sterol Oxidation Products in Plant Sterol Enriched Spreads, Fat Blends, and Plant Sterol Concentrates
Authors: Louter Arjan J H
Published: February 2020

Plant sterols (PS) are very stable molecules but may undergo oxidation due to the presence of a double bond in the ring structure. In order to assess whether this occurs during heating and storage, an analytical procedure was developed for the determination of concentration levels and identity of PS oxidation products in functional food ingredients and products. The method is based on cold saponification, solvent extraction of unsaponifiables, isolation of sterol oxidation products by means of liquid chromatography, and final analysis by gas chromatography (GC) with flame ionization detection. Identification of the key PS oxidation products was performed by means of GC-mass spectrometry (GC-MS). Isotope dilution MS was used to verify the absence of the formation of potential artifacts by the method. The method described is applicable to spreads (containing 20–65% water), oils, sterol esters, pure sterols, and fat extracts from food. The between-day reproducibility of the total content of sterol oxidation products in control samples sample was 8%, and of individual sterol oxidation products, 6–15%. The recovery of sterol oxidation products was 91%. The limit of detection was 0.1 mg/kg.
Cholesterol Oxidation in Meat-Based Baby Foods
Authors: Evangelisti Filippo , Zunin Paola , Boggia Raffaella , Calcagno Claudio
Published: February 2020

Cholesterol oxidation in commercial meat-based homogenized and freeze-dried baby foods was examined. The 7 major products of this reaction were determined by gas chromatography coupled with mass spectrometry (GC-MS). As far as single cholesterol oxidation products (COP) are concerned, 7-ketocholesterol was the major product of direct cholesterol oxidation in the 2 groups of analyzed samples, and this study confirmed that it is a useful marker of the whole cholesterol oxidation process. Nevertheless, the amounts of cholesterol-5β,6β-epoxide were often similar to and sometimes higher than the amounts of 7-ketocholesterol, thus showing a strong development of both direct and indirect cholesterol oxidation pathways. Total COP content was significantly higher in freeze-dried than in homogenized products. Moreover, in freeze-dried samples, the COP content per serving was quite variable and, in 2 samples, it was close to or even higher than 500 μg. The greater development of cholesterol oxidation in the freeze-dried samples was confirmed by their highest total COP/cholesterol percent ratios. A constant correlation between the fatty acid composition and the development of cholesterol oxidation was not found, although a positive correlation between unsaturated fatty acid content and total COP content occasionally exists in samples of the same brand.
Determination of Diazepam in Cream Biscuits by Liquid Chromatography
Authors: Ghosh Priyankar , Reddy Mudiam Mohanakrishna , Rao Beedu Sashidhar , Sarin Rajendra Kumar
Published: February 2020

An analytical procedure was developed for the detection and quantitation of diazepam in cream biscuits, which were used to commit crime. The method involves the extraction of diazepam with ethanol at room temperature, and the extract is filtered, evaporated to dryness, and redissolved in the mobile phase, methanol–acetonitrile–tetrahydrofuran–water (15 + 55 + 4 + 26, v/v). The separation is achieved on a C18 reversed-phase column with the mobile phase and diode array detection (λmax) at 230 nm. Medazepam is used as the internal standard is for quantification. The calibration plot for the determination of diazepam is based on linear regression analysis (y = 0.6687x + 0.0372; r2 = 0.995). The limit of detection for diazepam in the biscuit samples was estimated as 600 ng/mL. The limit of quantitation for diazepam was estimated as 1.75 μg/mL. The diazepam detected per piece of biscuit was found to be in the range of 0.27–0.45 mg. Pure diazepam was added to biscuit samples at 3 levels (100 and 500 μg/g, and 1 mg/g), and the recoveries were found to be 95%. The mean retention time of diazepam was 2.7 min and that of medazepam (IS) was 4 min. The relative standard deviations of the diazepam level in the biscuit samples were estimated to be 0.4% for retention time and 1.02% for peak area in intraday analysis, whereas the corresponding values were and 0.61 and 2.34% in interday analysis. The method is rapid and reliable for qualitative and quantitative analysis of cream biscuits laced with diazepam, and it can be used by law enforcement laboratories for routine analysis.
Relationships Between LC Retention, Octanol–Water Partition Coefficient, and Fungistatic Properties of 2-(2,4-Dihydroxyphenyl)benzothiazoles
Authors: Matysiak Joanna , Niewiadomy Andrzej , Senczyna Bogdan , Żabińska Anna , Rózyło Jan K
Published: February 2020

The retention behavior of newly synthesized compounds with antimycotic activity from the 2-(2,4-dihydroxyphenyl)benzothiazole group by high-performance liquid chromatography has been investigated. RP-18 stationary phase and methanol–acetate buffer aqueous mobile phases at pH 4 and 7.4 have been used. In the case of the mobile phase at pH 7.4, higher concentrations of water can be applied than at pH 4. The studied compounds showed regular retention behavior, their log k values decreasing linearly with an increasing concentration of methanol in the mobile phase. On the basis of these relationships, the lipophilicity (log kw), specific hydrophobic surface area (S), and isocratic chromatographic hydrophobicity index (φ0) were determined. Similar log kw values and sensitivity to changes in the structure of compounds studied for both mobile phases have been found. Moderate correlations between the chromatographic parameters and the calculated octanol-water log P values were found. Finally, the lipophilicity parameters were compared with the fungistatic properties of compounds expressed by log MIC (minimum inhibitory concentration) values to find quantitative structure activity relationship equations.
Determination of Thiabendazole in Orange Juice and Rind by Liquid Chromatography with Fluorescence Detection and Confirmation by Gas Chromatography/Mass Spectrometry After Extraction by Matrix Solid-Phase Dispersion
Authors: Albero Beatriz , Sánchez-Brunete Consuelo , Tadeo José L
Published: February 2020

A method was developed for the determination of thiabendazole (TBZ) in orange juice and rind based on matrix solid-phase dispersion (MSPD). TBZ was extracted with ethyl acetate and the extract was subsequently cleaned up on a solid-phase extraction column. Fungicide residues were determined by liquid chromatography with fluorescence detection. Recoveries through the method ranged from 87 to 97% with relative standard deviations ≤11%. The detection and quantitation limits were 0.15 and 0.50 μg/kg, respectively. The confirmation of TBZ residues in positive samples was performed by solid-phase microextraction followed by gas chromatography with mass spectrometric detection using selected ion monitoring. The developed method was applied to determine TBZ levels in commercial orange juices and in juice and rind of fresh oranges. The influence of storage and washing of fruits on TBZ residues was also studied.
Selected Uses of Enzymes with Critical Fluids in Analytical Chemistry
Authors: Turner Charlotta , King Jerry W , McKeon Thomas
Published: February 2020

The use of enzymes coupled with supercritical fluid (SF)-based analytical techniques, such as supercritical fluid extraction (SFE), provides a safer environment platform for the analytical chemist and reduces the use of organic solvents. Incorporation of such techniques not only reduces the use of solvent in analytical laboratories, but it can also lead to overall method simplification and time savings. In this review, some of the fundamental aspects of using enzymes in the presence of SF media are discussed, particularly the influence of extraction (reaction) pressure, temperature, and water content of the extracting fluid and/or the sample matrix. Screening of optimal conditions for conducting reactions in the presence of SF media can be readily accomplished with automated serial or parallel SFE instrumentation, including selection of the proper enzyme. Numerous examples are cited, many based on lipase-initiated conversions of lipid substrates, to form useful analytical derivatives for gas chromatography, liquid chromatography, or SF chromatography analysis. In certain cases, enzymatic-aided processing of samples can permit the coupling of the extraction, sample preparation, and final analysis steps. The derived methods/techniques find application in nutritional food analyses, assays of industrial products, and micro analyses of specific samples.
Determination of Trimetazidine Dihydrochloride in the Presence of Its Acid-Induced Degradation Products
Authors: Bebawy Lories I , El Tarras Mohammed F , El Sabour Samah A
Published: February 2020

Three methods are presented for the determination of trimetazidine dihydrochloride in the presence of its acid-induced degradation products. The first method was based on measurement of first-derivative D1 value of trimetazidine dihydrochloride at 282 nm over a concentration range of 8.00–56.00 μg/mL with mean percentage accuracy of 99.80 ± 1.17. The second method was based on first derivative of the ratio spectra DD1 at 282 nm over the same concentration range with the percentage accuracy of 99.14 ± 0.68. The third method was based on separation of trimetazidine dihydrochloride from its acid-induced degradation products followed by densitometric measurement of the spots at 215 nm. The separation was performed on silica gel 60 F254 using methanol–ammonia (100 + 1.5, v/v) as mobile phase. This method was applicable for determination of the intact drug in the presence of its degradation products over a concentration range of 2.00–9.00 μg/spot with mean percentage accuracy of 99.86 ± 0.92. The proposed methods were successfully applied for the determination of trimetazidine dihydrochloride in bulk powder, laboratory-prepared mixtures containing different percentages of degradation products, and pharmaceutical dosage forms. The validity of results was assessed by applying the standard addition technique. The results obtained agreed statistically with those obtained by the reported method.
Application of the Wavelet Method for the Simultaneous Quantitative Determination of Benazepril and Hydrochlorothiazide in Their Mixtures
Authors: Dinç Erdal , Baleanu Dumitru
Published: February 2020

The discrete and continuous wavelet transforms were applied to the overlapping signal analysis of the ratio data signal for simultaneous quantitative determination of the title subject compounds in samples. The ratio spectra data of the binary mixtures containing benazepril (BE) and hydrochlorothiazide (HCT) were transferred as data vectors into the wavelet domain. Signal compression, followed by a 1-dimension continuous wavelet transform (CWT), was used to obtain coincident transformed signals for pure BE and HCT and their mixtures. The coincident transformed amplitudes corresponding to both maximum and minimum points allowed construction of calibration graphs for each compound in the binary mixture. The validity of CWT calibrations was tested by analyzing synthetic mixtures of the investigated compounds, and successful results were obtained. All calculations were performed within EXCEL, C++, and MATLAB6.5 softwares. The obtained results indicated that our approach was flexible and applicable for the binary mixture analysis.
Application of Derivative Spectrophotometry for Simultaneous Determination of Quinapril and Hydrochlorothiazide in the Combination Tablets
Authors: Kowalczuk Dorota , Hopkała Hanna
Published: February 2020

A new second-order-derivative spectrophotometric method using zero-crossing technique measures quinapril (QUI) and hydrochlorothiazide (HYD) in 2-component mixtures. The procedure does not require prior separation of components from the sample. QUI was determined at a wavelength of 211.6 nm (zero-crossing wavelength point of HYD). Similarly, HYD was measured at 270.8 nm (zero-crossing wavelength point of QUI). Calibration graphs were constructed over the concentration range of 4.0 to 24.0 μ/mL for QUI and 2.5 to 15.0 μg/mL for HYD. Detection and quantitation limits were 0.85 and 2.5 μg/mL for QUI and 0.12 and 0.4 μg/mL for HYD, respectively. The accuracy (recovery 100.5–102%), precision (relative standard deviation less than 3.5% for QUI and 1.5% for HYD), selectivity, and sensitivity of the elaborated methods were satisfactory. The proposed method was applied successfully for the determination of both drugs in QUI-HYD tablets.
Feasibility of Reduction in Use of the Mouse Bioassay: Presence/Absence Screening for Saxitoxin in Frozen Acidified Mussel and Oyster Extracts from the Coast of California with In Vitro Methods.
Authors: Inami Gregory B , Crandall Claudia , Csuti Donna , Oshiro Michael , Brenden Rita A
Published: February 2020

In the United States, the detection of paralytic shellfish poisoning (PSP) for regulatory purposes relies on the mouse bioassay (MBA). Using a saxitoxin presence/absence test could reduce animal usage significantly. Three in vitro methods, the RIDASCREEN® Saxitoxin kit, MIST Alert™, and a 5 h neuroblastoma assay, were evaluated in parallel with the MBA using 106 twice-frozen, acidified extracts from California-grown mussel and oyster tissues. For each assay, a cutoff point was established whereby data below or equal to that point were scored as negative and were assigned a score of zero. Data above the cutoff were considered positive and assigned a score of one. Pearson correlation coefficients were generated. The RIDASCREEN, MIST Alert, and neuroblastoma bioassay correlated to the MBA at 0.849, 0.853, and 0.832 when used for presence/absence detection. These data suggest that a reduction in MBA usage could be achieved in the surveillance of California-grown mussels and oysters for PSP-associated toxins. Correlation data between the in vitro assays, cost comparisons, and the potential for false negatives and false positives were examined. Implications of these methodologies in protecting public health are discussed.
Immunoassay Kit Used to Detect the Presence of Bovine Material in Processed Foods
Authors: Love John L , Carey-Smith Gwyneth V
Published: February 2020

The Tepnel™ Bio Kit for the detection of beef in cooked foods was assessed to determine its validity in demonstrating if food being imported into New Zealand contains beef material. The test suffered no interference from the presence of other common nonbovine species meats accepted as food within New Zealand and it detected beef in cooked samples of mixed meats when the proportion of beef in the mixture was >2 or >1%, depending on other meat species present. The documentation supplied with the kit indicates that the specific proteins it measures in cooked beef are stable to 130°C. This was confirmed in the literature when the kit was used to test meat and bone meal cooked to at least 133°C. However, our results showed these proteins to be much less stable when heated to elevated temperatures in moist food under pressure, and samples containing beef ceased to be positive by the immunoassay test after being autoclaved to 121°C. This suggests that the test may not be able to detect even relatively high levels of beef in low-acid canned foods, which are normally retorted under pressure to approximately 121°C.
An Interlaboratory-Verified Method for the Determination of Vitamins Aand E inMilk- and Soy-Based Infant Formula by Liquid Chromatography with Matrix Solid-Phase Dispersion Extraction
Authors: Chase G William , Ye Lin , Stoakes Vicky C , Eitenmiller Ronald R , Long Austin R
Published: February 2020

An interlaboratory-verified, liquid chromatographic (LC) method is presented for determination of all-racemic α-tocopheryl acetate and retinyl palmitate in infant formula. The extraction procedure uses matrix solid-phase dispersion. A sample is mixed with C18, and the mixture is packed into a reservoir and eluted with selective solvents to extract the analytes. After evaporation and filtration, the sample extract is injected directly into a normal-phase LC system with fluorescence detection. All-racemic α-tocopheryl acetate and retinyl palmitate are quantitated isocratically with a mobile phase of hexane containing isopropanol at 0.2% (v/v) and 0.125% (v/v), respectively. A nonfortified zero control reference material (ZRM) was spiked at 5 levels, with 5 replicate analyses of 1/2x, x, 2x, 4x, and 16x where “x” represents the minimum levels of 250 IU/100 kcal (vitamin A) and 0.7 IU/100 kcal (vitamin E) as specified in Title 21 of the Code of Federal Regulations, part 107.100. Recoveries of retinyl palmitate ranged from 83.8 to 107%, and those of all-racemic α-tocopheryl acetate ranged from 87.7 to 108%. Two additional laboratories analyzed the ZRM samples at 4 spiking levels with 6 replicates. Recoveries of retinyl palmitate and all-racemic α-tocopheryl acetate ranged from 92.2 to 104% and from 91.7 to 101%, respectively, in the second laboratory. Recoveries of retinyl palmitate and all-racemic α-tocopheryl acetate ranged from 85.3 to 97.0% and from 86.6 to 110%, respectively, in the third laboratory. Relative standard deviations for all 3 laboratories ranged from 0.2 to 7.5% with an average of 2.9%. In addition, each laboratory analyzed a commercial milk- and commercial soy-based infant formula. Excellent agreement in results was obtained between the 3 laboratories for vitamins A and E in all matrixes.
Extension of AOAC Official Method 999.14 (Choline in Infant Formula and Milk) to the Determination of Choline in Dietary Supplements
Authors: Rader Jeanne I , Weaver Carol M , Trucksess Mary W
Published: February 2020

AOAC Official Method 999.14 is applicable for the determination of choline in milk and infant formulas. To date, its use has not been extended beyond these matrixes. We modified Official Method 999.14 and applied it to the determination of choline in a range of choline-containing dietary supplements. Dietary supplement tablets, capsules, wafers, softgels, liquid products, and drink powders were included. We found that the standard curve could be extended to cover a wider range of choline concentrations and defined a procedure for the use of Norit for samples in which the vitamin C content was high enough to interfere with the analysis. Recoveries of choline added to infant formula powders and to representative dietary supplement tablets, capsules, powdered drink mix, and wafer products were 85–114%. The use of Norit during the procedure did not affect the recovery of choline added to infant formula powders or to dietary supplements. An alkaline digestion was included for use with a product containing lecithin as the sole source of choline.
Detection of Soy Proteins in Processed Foods: Literature Overview and New Experimental Work
Authors: Koppelman Stef J , Lakemond Catriona M M , Vlooswijk Riek , Hefle Susan L
Published: February 2020

Several tests for the detection of soy proteins in foods have been described in the literature, and some are commercially available. This article gives an overview of these methods and discusses the advantages and disadvantages of each individual method. Based on the conclusions of this inventory, an experimental approach was designed to improve the sensitivity of measuring soy protein in processed foods. The aimed sensitivity is 10 ppm (10 μg soy protein in 1 g solid sample), which is over 100-fold lower than presently available tests. The aimed sensitivity is this low because levels of food allergens at 10 ppm and above may provoke reactions in food allergic persons. Native soybean meal, soy protein isolate, soy protein concentrate, and textured soy flakes were used as test materials. Several extraction procedures were compared and a new method using high pH was selected. Polyclonal antibodies were raised in rabbits and goats, and immunopurified antibodies were used in sandwich and inhibition enzyme-linked immunosorbent assay (ELISA). Extraction at pH 12 resulted in good yields for all tested samples, both quantitatively (Bradford) and qualitatively by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Immunopurified rabbit antibodies against this extract used in a competition ELISA format resulted in a sensitive test with a detection limit of 0.02 μg/mL, corresponding to 0.4 μg/g (0.4 ppm) in food samples. Cross-reactivity with some main food ingredients was measured and appeared to be negative in all cases. The presently developed test is applicable for soy ingredients and soy-containing foods that are processed in different ways. The limit of quantitation is 1 ppm, which is an enormous improvement over earlier described methods.
Applications of Array Biosensor for Detection of Food Allergens
Authors: Shriver-Lake Lisa C , Taitt Chris Rowe , Ligler Frances S
Published: February 2020

Although food is a necessity, compounds within food products can be dangerous and life-threatening for people with food allergies. These allergy-causing compounds, such as proteins from eggs and milk, must be identified on the labels of commercial products. Unintentional contamination of food with these compounds occurs as a result of storage, manufacturing procedures, or cleaning procedures. A sensitive, specific, and rapid method to identify foods containing allergens is required by the food industry. The array biosensor, a rapid detection system, may provide a solution to this need. The array biosensor performs fluorescent immunoassays on the surface of a planar waveguide by first running samples, then fluorescently labeled antibodies, over a surface patterned with capture antibodies. An optical image is captured by a charged-coupled device camera and converted into fluorescence values. Signal intensity and spot location provide information on the compound and its concentration. The array biosensor has been successfully demonstrated for toxin, bacteria, and virus detection at low levels in under 20 min in food, clinical samples, and environmental matrixes. An assay for detection of ovalbumin as an indicator of egg contamination has been developed with limits of detection of 25 pg/mL in buffer and 1.3 ng/mL (13 ng/g) in non-egg pasta extract (buffer:pasta 10:1, v/w).
Rapid Determination ofMoisture/Solids and Fat in Dairy Products by Microwave and Nuclear Magnetic Resonance Analysis: PVM 1:2004
Authors: Cartwright Gary , McManus Bobbie H , Leffler Timothy P , Moser Cindy R
Published: February 2020

A peer-verified method is presented for the determination of percent moisture/solids and fat in dairy products by microwave drying and nuclear magnetic resonance (NMR) analysis. The method involves determining the moisture/solids content of dairy samples bymicrowave drying and using the dried sample to determine the fat content by NMR analysis. Both the submitting and peer laboratories analyzed various dairy products by using a CEM SMART system (moisture) and the SMART Trac (fat). The samples included milks, creams, ice cream mix, sour cream, yogurt, cream cheese, and mozzarella, Swiss, and cheddar cheeses. These samples represented a range of products that processors deal with in daily plant operations. The results were compared with moisture/solids and fat values derived from AOAC-approved methods.
Polymerase Chain Reaction-Restriction Fragment Length Polymorphism Analysis of Mitochondrial cytb Gene from Species of Dairy Interest
Authors: Lanzilao Irene , Burgalassi Francesca , Fancelli Silvia , Settimelli Mario , Fani Renato
Published: February 2020

Species identification plays an important role in food allergy prevention and food substitution detection that can reduce the commercial value of a product. For these reasons, many molecular methods have been developed to determine species origin; among them, polymerase chain reaction (PCR)-based methods were successfully applied to processed or unprocessed foodstuffs. An updated PCR-RFLP (restriction fragment length polymorphism) method of the cytb gene was developed for the identification of the 4 species of main interest in the dairy industry (Bos, Ovis, Capra, Bubalus). The comparative analysis of the 92 cytb sequences available in the database belonging to the 4 species allowed identification of 2 highly conserved regions, which were used to design 2 oligonucleotides for the PCR amplification of a 275 base-pair (bp) cytb fragment. The in silico analysis allowed identification of a set of species-specific restriction endonucleases (HaeIII, TaqI, and MwoI), which generated easily analyzable species-specific restriction profiles of the 275 bp cytb DNA fragment. The system was developed for both purified DNA and DNA extracted from meat or dairy products and finally tested on mixed samples, indicating its applicability to foodstuffs.
Polymerase Chain Reaction Technology as Analytical Tool in Agricultural Biotechnology
Authors: Lipp Markus , Shillito Raymond , Giroux Randal , Spiegelhalter Frank , Charlton Stacy , Pinero David , Song Ping
Published: February 2020

The agricultural biotechnology industry applies polymerase chain reaction (PCR) technology at numerous points in product development. Commodity and food companies as well as third-party diagnostic testing companies also rely on PCR technology for a number of purposes. The primary use of the technology is to verify the presence or absence of genetically modified (GM) material in a product or to quantify the amount of GM material present in a product. This article describes the fundamental elements of PCR analysis and its application to the testing of grains. The document highlights the many areas to which attention must be paid in order to produce reliable test results. These include sample preparation, method validation, choice of appropriate reference materials, and biological and instrumental sources of error. The article also discusses issues related to the analysis of different matrixes and the effect they may have on the accuracy of the PCR analytical results.
Acrylamide: Considerations for Risk Management
Authors: Slayne Martin A , Lineback David R
Published: February 2020

The presence of acrylamide in many carbohydrate-rich foods is due to its formation during conventional heating and preparation methods. Although acrylamide is established to be a toxic substance, the implications to public health from the amounts found in food are not clear. A better scientific understanding is required to help determine whether, and to what extent, formal risk management action might be necessary. Since acrylamide in food was highlighted in 2002, numerous investigations and initiatives have been developed, including international collaborations across governments, industry, research organizations, and consumer representations. The newly generated information is being used to help the overall understanding of this issue. In particular, new information on health aspects will be important to update the scientific risk assessment. The basis for decisions on possible risk management measures would then be clearer. If future risk assessment concludes that the amounts of acrylamide in food can pose a health threat, then options for risk management will need to be considered, such as limits, guide levels, codes of practice, guidance information, and advice to the food and catering industries and to consumers. In the meantime, it is possible to benefit from progress already made on how acrylamide is formed in food and on ways to lower the amounts present. Raising awareness to the approaches that can reduce the presence of acrylamide in food should be encouraged. Where feasible, such approaches can be assessed for practical use in production, processing, and preparation of the relevant food products.
Acrylamide: Update on Selected Research Activities Conducted by the European Food and Drink Industry
Authors: Taeymans Dominique , Andersson Anders , Ashby Peter , Blank Imre , Gondé Pierre , Eijck Paul van , Faivre Virginie , Lalljie Sam P D , Lingnert Hans , Lindblom Marianne , Matissek Reinhard , Müller Detflef , Stadler Richard H , Studer Alfred , Silvani David , Tallmadge Dan , Thompson Geoff , Whitmore Tricia , Wood John , Zyzak David
Published: February 2020

This paper reviews the progress made by the European food and drink industry (CIAA) on acrylamide with regard to analytical methods, mechanisms of formation, and mitigation research in the major food categories. It is an update on the first CIAA review paper, “A Review of Acrylamide: An Industry Perspective on Research, Analysis, Formation and Control.” Initial difficulties with the establishment of reliable analytical methods, in most cases, have now been overcome, but challenges remain in terms of the need to develop simple and rapid test methods and certified reference materials. Many trials have been conducted under laboratory and experimental conditions in a variety of foods, and a number of possible measures have been identified to relatively lower the amounts of acrylamide in food. Promising applications were studied in reconstituted potato models by addition of amino acids or use of asparaginase. In bakery wares, predictive models have been established to determine the role of ammonium carbonate and invert sugar in acrylamide formation. Studies in several commercial foods showed that acrylamide is not stable over time in roasted and ground coffee. Some progress in relatively lowering acrylamide in certain food categories has been achieved, but at this stage can only be considered marginal. Any options that are chosen to reduce acrylamide in commercial products must be technologically feasible and must not adversely affect the quality and safety of the final product.
The HEATOX Project
Authors: Hellenäs Karl-Erik , Abramsson-Zetterberg Lilianne , Skog Kerstin
Published: February 2020

HEATOX is the acronym for a European Union-funded project entitled Heat-Generated Food Toxicants: Identification, Characterization, and Risk Minimization. Acrylamide will be the main experimental focus, but identification of unknown toxicants in heated carbohydrate-rich foods will also be attempted. The project includes research on formation chemistry, food technology, analytical methods, hazard characterization, and exposure assessment. The results will finally be used in risk assessment and risk management advice.
Determination of β-Agonist Residues in Bovine Urine Using Liquid Chromatography-Tandem Mass Spectrometry
Authors: Dickson Leslie C , MacNeil James D , Lee Stephen , Fesser Adrian C E
Published: February 2020

A multiresidue method was developed and validated to screen bovine urine samples for 10 β-2-adrenergic agonistic drugs—brombuterol, cimaterol, clenbuterol, clenpenterol, isoxsuprine, mabuterol, ractopamine, ritodrine, salbutamol, and tulobuterol—at the 2 μg/L level. The method is also quantitative in the range of 1 to 4 μg/L for all analytes except salbutamol. The procedure uses enzymatic digestion, liquid–liquid extraction, and cleanup on solid-phase extraction columns, followed by detection using a liquid chromatograph-tandem quadrupole mass spectrometer operated in the positive-ion atmospheric pressure chemical ionization multiple-reaction monitoring mode. Method validation included assessment of recoveries, repeatabilities, linearity of responses, decision limits, and detection capabilities. Overall average recoveries ranged from 70–91%; recoveries were generally lower for salbutamol. The decision limits ranged from 0.4–1.0 μg/L, and detection capabilities from 0.6–1.7 μg/L.
Fast Antimicrobial Screen Test (FAST): Improved Screen Test for Detecting Antimicrobial Residues in Meat Tissue
Authors: Dey Bhabani P , Thaker Nitin H , Bright Susan A , Thaler Alice M
Published: February 2020

The Fast Antimicrobial Screen Test (FAST) is a simple and quick screening test developed to detect antibiotic and sulfonamide residues in food animal carcasses in slaughter establishments. This microbial inhibition test detects antimicrobials that are allowed to be used in food animals. It has the ability to detect these antimicrobials at or above the allowable limit in carcass kidney fluids in 6 h. Laboratory evaluations show that the lower limit of detection (LLD) of FAST and the Calf Antibiotic and Sulfa Test (CAST) for antibiotics tested was the same, but the LLD for sulfonamides of FAST was lower than the LLD of CAST. Compared with the Swab Test on Premises (STOP) developed in 1977, the LLD's of FAST for both antibiotics and sulfonamides were significantly better. Under field conditions, the sensitivity of FAST and CAST to antibiotic and sulfonamide residues in animal kidneys was not significantly different, but the time required by FAST was significantly lower than CAST (6 versus 18 h). Compared with the STOP, the sensitivity and the range of detection by FAST for all antimicrobials were significantly higher and the testing time was lower (18 versus 6 h).
Focused Ultrasound Versus Microwave Digestion for the Determination of Lead in Must by Electrothermal-Atomic Absorption Spectrometry
Authors: Capelo Jóse L , Catarino Sofia , Curvelo-Garcia António S , Vaiâo Miguel
Published: February 2020

The content of metals at the different stages of the winemaking process is of great concern because of legal and wine quality reasons. In the present work, we have developed a new fast procedure for metal extraction from must based on focused ultrasound with HNO3 and H2O2, with which microwave digestion of the must is not necessary. Lead was used as a model element to achieve the optimum combination of reagents in order to achieve total extraction. Results were compared with those obtained after microwave digestion of the samples. In addition, conventional and fast programs in conjunction with different matrix modifiers were studied. The method requires few sample mass (ca 0.5 g) and few reagents in low volume (HNO3 50 μL and H2O2 100 μL). The total sample treatment time is only 60 s.
Confirmation of Sulfamethazine, Sulfathiazole, and Sulfadimethoxine Residues in Condensed Milk and Soft-Cheese Products by Liquid Chromatography/Tandem Mass Spectrometry
Authors: Clark Susan B , Turnipseed Sherri B , Madson Mark R , Hurlbut Jeffrey A , Kuck Laura R , Sofos John N
Published: February 2020

A liquid chromatography/tandem mass spectrometry method (LC/MS/MS) is described for the simultaneous detection of 3 sulfonamide drug residues at 1.25 ppb in condensed milk and soft-cheese products. The 3 sulfonamide drugs of interest are sulfathiazole (STZ), sulfamethazine (SMZ), and sulfadimethoxine (SDM). The method includes extraction of the product with phosphate buffer, centrifugation of the diluted product, and application of a portion of the extract onto a polymeric solid-phase extraction cartridge. The cartridge is washed with water, and the sulfonamides are eluted with methanol. After evaporation, the residue is dissolved in 0.1% formic acid solution, and the solution is filtered before analysis by LC/MS/MS. The LC/MS/MS program involved a series of time-scheduled selected-reaction monitoring transitions. The transitions of MH+ to the common product ions at m/z 156, 108, and 92 were monitored for each residue. In addition, SMZ and SDM had a fourth significant and unique product ion transition that could be measured. Validation was performed with control and fortified-control condensed bovine milk with 2.5, 5, and 10 ppb sulfonamides. This method was applied to imported flavored and unflavored condensed milk and cream cheese bars. The presence of STZ and SMZ residues was confirmed in 3 out of 6 products.
The Use of Electrodialysis to Prepare Aqueous Bread Extracts for Bromate Determination by Chemiluminescence
Authors: Himata Katsuichi , Warner Charles , Currie Douglas , Graves Qian , Diachenko Gregory
Published: February 2020

A cleanup procedure based on electrodialysis is described for the preparation of aqueous bread extracts for bromate determination by chemiluminescence. The technique utilizes electrophoresis with 3 chambers separated by semipermeable membranes. The relative merits of reverse osmosis (RO), ultrafiltration, and nanofiltration membranes with various molecular weight cutoffs were evaluated. The best results were obtained with an RO membrane manufactured from thin-film (composite) polysulfone as support for polyamide. A 0.14M sodium sulfate solution in the center or collection chamber provides optimum conductivity. Aqueous hydroxylamine sulfate (30mM) was selected for the anode compartment as a reductant for the anode oxidation products. The constant current mode at 150 mA with a potential of ca 100 volts was used. After electrophoretic separation, the bromate concentration in the collection chamber was typically 2 to 3 times greater than the concentration in the bread extract. The chemiluminescent reaction of bromate with sulfite with hydrocortisone as the enhancer was selected for detection of bromate. The emission, with a wavelength maximum at 575 nm, was found to “glow” rather than “flash” after the reagents were mixed; therefore, it was possible to optimize the light collection period. The method was validated with a variety of commercial bread products. White bread, hot dog buns, hamburger rolls, and a multigrain bread from 7 different manufacturers were studied.
Comparison of Total Folate Concentrations in Foods Determined by Microbiological Assay at Several Experienced U.S. Commercial Laboratories
Authors: Koontz John L , Phillips Katherine M , Wunderlich Kelli M , Exler Jacob , Holden Joanne M , Gebhardt Susan E , Haytowitz David B
Published: February 2020

Analysis of total folate concentration measured by microbiological assay in a variety of foods submitted in a routine manner to experienced laboratories that regularly perform folate analysis on fee-for-service basis was evaluated. Homogenates of fresh strawberries, frozen spinach, orange juice, frozen meat and vegetable pizza, dry macaroni, and dried pinto beans were prepared and stored under conditions previously determined to maintain stability of folate content. An aliquot of each composite and of 3 certified reference materials were sent on each of 4 occasions to 4 laboratories. Results for macaroni and pizza, the only folic acid-fortified foods, had considerably lower between-laboratory variation (CVB) with CVB of 9–11% versus >45% for other foods. Mean total folate ranged from 14 to 279 μg/100 g for a mixed vegetable reference material, from 5 to 70 μg/100 g for strawberries, and from 28 to 81 μg/100 g for wholemeal flour. Only 1 laboratory reported using a tri-enzyme extraction, and all laboratories used folic acid fortified foods as internal control materials. Users of commercial total folate analysis should understand the uncertainty in values determined by microbiological assay, particularly for foods containing primarily naturally occurring folate, which may not be apparent when replicate samples are not submitted for analysis.
Extraction of Fipronil and Thiobencarb from Anaerobic Water Samples Using Solid-Phase Extraction
Authors: Doran Gregory , Helliwell Stuart , Eberbach Philip
Published: February 2020

Anaerobic water samples containing levels of soluble Fe(II) may form insoluble Fe(III) particulates that could hinder subsequent extraction and analysis. Solid-phase extraction (SPE) cartridges could become blocked by this material, reducing the volume that can be processed. The ability of ascorbic acid to reduce these Fe(III) colloids and/or to prevent further oxidation of Fe(II) by dissolved oxygen during sampling was investigated and compared to sample stabilization with hydrochloric acid. Ascorbic acid (5%, w/v) proved the most effective treatment because it prevented 95% of the dissolved iron in the sample from precipitating during processing, compared to 40% in untreated samples. The effect of ascorbic acid addition on degradation of 2 rice pesticides, fipronil and thiobencarb, was investigated and compared to degradation rates in water. Pesticide reduction by ascorbic acid over a 3 h period was insignificant compared to the natural degradation occurring in deionized water. While this method was shown to increase sample processing time, it also allowed the processing of large-volume anaerobic water samples (150 mL) that were previously not extractable due to rapid obstruction of the SPE cartridge.
The Absorption and Metabolism of Modified Amino Acids in Processed Foods
Authors: Finot Paul-André
Published: February 2020

The chemical reactions involved in the modifications of amino acids in processed food proteins are described. They concern the Maillard reaction, reaction with polyphenols and tannins, formation of lysinoalanine during alkaline and heat treatments, formation of isopeptides, oxidation reaction of the sulfur amino acids, and isomerization of the L-amino acids into their D-form. Information on the digestion, absorption, and urinary excretion of the reaction products obtained by using conventional nutritional tests is given. The studies that have been made on the metabolism of these molecules by using a radioisotopic approach to follow their kinetics in the organism after ingestion are also reviewed. This approach provides unique data on the quantitation of the metabolic pathways and on the kinetics of the metabolic processes involved.
Validation of a Capillary Electrophoresis Method for Analysis of Rabeprazole Sodium in a Pharmaceutical Dosage Form
Authors: Garcia Cássia V , Sippel Juliana , Sfair Leticia L , Garcia Silvia S , Jablonski André , Steppe Martin , Schapoval Elfrides E S
Published: February 2020

Rabeprazole sodium is an antisecretory agent that inhibits the enzyme H+/K+ ATPase present in the stomach parietal cells. There are few data about its quantitative determinations in laboratorial routines. Capillary electrophoresis is a method being used increasingly for analysis of pharmaceutical compounds, the main advantages of which are the simplicity of instrumentation, low consumption of sample and reagents, and fast analysis. The aim of this study was to develop and validate a capillary electrophoresis method for determination of rabeprazole sodium in coated tablets. The conditions used were a bare fused silica capillary with 48.0 cm length (39.5 cm effective) and 75 μm id; a 10mM, pH 9.0, sodium tetraborate run buffer; a diode array detector set at 291 nm; hydrodynamic injection (50 mbar/5 s); and a voltage of 20 kV. HP Chemstation CE rev. A.06.03 software was used for system control, data acquisition, and analysis. The method was demonstrated to be linear in the concentration range of 5.0–40.0 μg/mL (r = 0.9993), precise (interday relative standard deviation = 0.49), accurate (mean recovery = 103.1%), and specific. The limits of detection and quantitation were 1.29 and 3.91 μg/mL, respectively.