Biogenic amines in commercially produced Yulu,a Chinese fermented fish sauce

Seven biogenic amines were determined in 35 commercially produced Yulu samples from three provinces of China by pre-column derivatisation with dansyl chloride (Dns-Cl) and high-performance liquid chromatography with fluorescence detection (HPLC-FLD). Putrescine, cadaverine, histamine and tyramine were the major biogenic amines (more than 100 mg kg^?1), while tryptamine, spermidine and spermine were regarded as minor biogenic amines (less than 25 mg kg^?1). Twenty samples contained more than 50 mg kg^?1 histamine (the limit for histamine in seafood products as suggested by the Food and Drug Administration). Twenty-one samples contained more than 100 mg kg^?1 tyramine and 10 contained more than 1000 mg kg^?1 total biogenic amines. This study provided data on biogenic amine levels in Chinese fermented fish sauce. The results suggested that biogenic amine content should be monitored in commercially produced Yulu.     

Simultaneous Determination of Squalene, α-Tocopherol and β-Carotene in Table Olives by Solid Phase Extraction and High-Performance Liquid Chromatography with Diode Array Detection

Olives, the fruit of the Olea europaea tree, are highly appreciated in olive oil and table olives (20 % of crops) not only for their flavor but also for their nutritional properties, especially for antioxidant compounds such as squalling (SQ), α-tocopherol (TH) and β-carotene (BC). This paper presents a new analytical method for simultaneously determining SQ, TH and BC in table olives by using solid phase extraction (SPE) and high performance-liquid chromatography with diode array detection (HPLC-DAD), avoiding the classic saponification process. The correlation coefficients of calibration curves of the analyzed compounds ranged from 0.998 to 0.999, and the recoveries were in the range of 89.4–99.6 %. The validated method was used to analyze 30 table olive samples from Italy for their content of SQ (537–1,583 mg kg^?1), TH (21–90 mg kg^?1) and BC (0.4–2.6 mg kg^?1). Finally, experiments with HPLC-MS were conducted to compare this novel method with the classic saponification procedure.     

Occurrence of 3-MCPD and glycidyl esters in edible oils in the United States

Fatty acid esters of 3-monochloropropanediol (3-MCPD) and glycidol are processing contaminants found in a wide range of edible oils. While both 3 MCPD and glycidol have toxicological properties that at present has concerns for food safety, the published occurrence data are limited. Occurrence information is presented for the concentrations of 3-MCPD and glycidyl esters in 116 retail and/or industrial edible oils and fats using LC-MS/MS analysis of intact esters. The concentrations for bound 3-MCPD ranged from below the limit of quantitation (<LOQ) to 0.09 mg kg^?1 (ppm) in 22 unrefined oils and from 0.005 to 7.2 mg kg^?1 (ppm) in 94 refined oils. The concentrations for bound glycidol ranged from <LOQ to 0.03 mg kg^?1 (ppm) in unrefined oil samples and from <LOQ to 10.5 mg kg^?1 (ppm) in processed oil samples. The highest concentrations for both 3-MCPD and glycidol were seen in refined palm oil and palm olein samples. Palm olein samples also contained a higher percentage of 3-MCPD in mono-ester form than any other type of oil.     

Assessment of the dietary intake of propylene glycol in the Korean population

An improved method for the analysis of propylene glycol (PG) in foods using a gas chromatography-flame ionisation detector (GC-FID), with confirmation by GC-MS, was validated by measuring several analytical parameters. The PG concentrations in 1073 products available in Korean markets were determined. PG was detected in 74.1% of the samples, in a concentration range from the limit of detection (n.d., 0.39 μg ml^?1) to 12,819.9 mg kg^?1. The Korea National Health and Nutrition Examination Survey (KNHANES) 2011–2013 reported the mean intake levels of PG from all sources by the general population and consumers were 26.3 mg day^?1 (0.52 mg kg^?1 day^?1) and 34.3 mg day^?1 (0.67 mg kg^?1 day^?1), respectively. The 95th percentile intake levels of the general population and consumers were 123.6 mg day^?1 (2.39 mg kg^?1 day^?1) and 146.3 mg day^?1 (2.86 mg kg^?1 day^?1), respectively. In all groups of the general population, breads were the main contributors to the total PG intake. These reports provide a current perspective on the daily intake of PG in the Korean population.     

The application of d-SPE in the QuEChERS method for the determination of PAHs in food of animal origin with GC–MS detection

This paper reports the evaluation of the Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method for the determination of polycyclic aromatic hydrocarbons (PAHs) in food of animal origin with GC–MS detection. Although in the available literature, there is a lot of information about sample preparation method for PAHs determination in food samples, but the QuEChERS method application for PAHs determination in food of animal origin has not been reported as yet. The results showed that the best recovery ratios 72.4–110.8 % with relative standard deviation lower than 10 % for all determined compounds were received for the method with ethyl acetate as an extraction solvent, primary–secondary amine and C₁₈ sorbents and evaporation to dryness and dissolving the residues in the hexane. The limit of quantification ranged from 0.0003 to 0.0030 mg kg^?1 for pyrene and benzo[a]anthracene, respectively. This method was also used for the determination of PAHs in 15 samples of pork ham. In 8 of 15 samples selected, PAHs were identified. It was observed that in 6 cooked ham and one smoked and cooked samples, any PAHs were found. In other samples, which were smoked and roasted, some low concentration of PAHs was detected. In one sample benzo[a]pyrene (0.0015 mg kg^?1), in one sample benzo[b]fluoranthene (0.0015 mg kg^?1) and in one sample chrysene (0.0024 mg kg^?1) were detected. A number of other less harmful PAHs were also determined. There were no exceedances of maximum levels (according to Commission Regulation (EU) No 835/2011) for determined PAHs in any of the analysed samples.     

Simultaneous Determination of Alkaloids in Green Coffee Beans from Ethiopia: Chemometric Evaluation of Geographical Origin

The alkaloid compositions of 99 green coffee (Coffea arabica L.) bean samples comprising eight varieties (Harar, Jimma, Kaffa, Wollega, Sidama, Yirgachefe, Benishangul and Finoteselam) from the major production regions of Ethiopia were investigated. High performance liquid chromatography was applied for the simultaneous determination of four coffee alkaloids in the aqueous extracts of the beans. The limits of detection for the method were established as 13 mg kg^?1 for trigonelline, 7 mg kg^?1 for theobromine, 8.5 mg kg^?1 for caffeine and 4 mg kg^?1 for theophylline in the dry coffee beans. Theophylline was not detected in any of the samples. The determined concentrations (% w/w dry coffee beans) ranged from 0.98 to 1.32 % for trigonelline, 0.0048 to 0.0094 % for theobromine and 0.87 to 1.38 % for caffeine. The concentrations of the alkaloids varied significantly, depending on the geographical origin of the beans. Theobromine was not detected in coffee beans from the East (Harar coffees), and its absence in samples can be used to ascertain whether the coffee originates from this region. Coffee beans from the Northwest were characterized by higher concentrations of caffeine. Application of linear discriminant analysis provided 75 % correct classification of samples into the respective production regions, with a 74 % prediction success rate. The moderate classification efficiency obtained when using alkaloid data demonstrates the potential of using this class of compounds in discriminant models for determination of the geographical origin of green coffee beans from Ethiopia.     

3-Monochloropropane-1,2-diol fatty acid esters in commercial deep-fat fried foods

Levels of 3-monochloropropane-1,2-diol (3-MCPD) fatty acid esters were evaluated in commercial deep-fat fried foods from the Brazilian market using a GC-MS method preceded by acid-catalysed methanolysis. A limit of detection of 0.04 mg kg^?1, a limit of quantitation of 0.08 mg kg^?1, mean recoveries varying from 82% to 92%, and coefficients of variation ranging from 2.5% to 5.0% for repeatability and from 3.6% to 6.5% for within-laboratory reproducibility were obtained during in-house validation. The levels of the compounds in the evaluated samples, expressed as free 3-MCPD equivalent, ranged from not detected to 0.99 mg kg^?1, and the highest concentrations were observed in samples of chopped onion and garlic. A preliminary estimation of 3-MCPD intake using these occurrence data suggested low risks to human health, but a potential concern may arise in particular cases of consumers of fried food.     

Heavy metals in vegetables sold in the local market in Jordan

Heavy metals (As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn) in various vegetables (cabbage, green onion, lettuce, parsley, rocket, spinach, carrot, onion, potato and cauliflower) from the market in Jordan were measured using inductively coupled plasma-mass spectrometry. As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn ranged from 0.009–0.275 mg kg^?1 wet weight, 0.004–0.060 mg kg^?1, 0.003–0.401 mg kg^?1, 0.105–3.51 mg kg^?1, 0.15–1.15 mg kg^?1, 0.93–14.39 mg kg^?1, 0.044–0.702 mg kg^?1, 0.072–0.289 mg kg^?1 and 2.23–6.65 mg kg^?1, respectively. Parsley, followed by spinach, contained the highest concentration of heavy metals. Onion contained high levels of toxic heavy metals. The content of Cu in parsley and spinach and Pb in onion exceeded the Codex limits. However, the daily intake of heavy metals from the tested vegetables was lower than the maximum limits for allowable intake.     

Migrated phthalate levels into edible oils

The determination of phthalates in edible oils (virgin olive oil, olive oil, canola oil, hazelnut oil, sunflower oil, corn oil) sold in Turkish markets was carried out using gas chromatography–mass spectrometry. Mean phthalate concentrations were between 0.102 and 3.863 mg L^?1 in virgin olive oil; 0.172 and 6.486 mg L^?1 in olive oil; 0.501 and 3.651 mg L^?1 in hazelnut oil; 0.457 and 3.415 mg L^?1 in canola oil; 2.227 and 6.673 mg L^?1 in sunflower oil; and 1.585 and 6.248 mg L^?1 in corn oil. Furthermore, the influence of the types of oil and container to the phthalate migration was investigated. The highest phthalate levels were measured in sunflower oil. The lowest phthalate levels were determined in virgin olive oil and hazelnut oil. The highest phthalate levels were determined in oil samples contained in polyethylene terephthalate.     

Sodium benzoate and potassium sorbate preservatives in food stuffs in Iran

A high-performance liquid chromatography method was applied for the determination of the levels of benzoate and sorbate in 400 food samples, including pickled cucumbers, canned tomato pastes, sour cherry jams, soft drinks, fruit juices and dairy products (UF-Feta cheeses, Lighvan cheeses, lactic cheeses, yogurts and doogh). The results showed that 270 (67.5%) of all samples contained benzoate ranging from 11.9 to 288.5 mg kg^?1 in lactic cheese and fruit juice, respectively. The levels of sorbate in 98 (24.5%) of the samples were 20.1 to 284.3 mg kg^?1 in doogh and fruit juice, respectively. Moreover, benzoate was detected in all dairy products ranging from 11.9 mg kg^?1 in lactic cheese to 91.2 mg kg^?1 in UF-Feta cheese. A low concentration of benzoate could originate naturally, due to specific biochemical mechanisms during cheese, yogurt and doogh maturation. In conclusion, a minimum level for benzoate in dairy products should be defined in the legislation.     

Aflatoxin M1 in raw milk from different regions of São Paulo state – Brazil

A total of 635 raw milk samples from 45 dairy farms, from three regions of São Paulo state – Brazil, were evaluated during 15 months for aflatoxin M₁ (AFM₁). AFM₁ was determined by high performance liquid chromatograph with fluorescence detection. AFM₁ was detected (>0.003 µg kg^?1) in 72.9%, 56.3% and 27.5% of the samples from Bauru, Araçatuba and Vale do Paraíba regions, respectively. The mean AFM₁ contamination considering all the samples was 0.021 µg kg^?1. Furthermore, the concentration of AFM₁ was quite different among Bauru (0.038 µg kg^?1), Araçatuba (0.017 µg kg^?1) and Vale do Paraíba (<0.01 µg kg^?1) regions. Only three samples (0.5%) had higher contamination than the tolerated limit in Brazil (0.50 µg kg^?1) and 64 samples (10.1%) had a higher contamination than the maximum limit as set by the European Union (0.050 µg kg^?1). The estimated AFM₁ daily intake was 0.358 and 0.120 ng kg^?1 body weight per day for children and adults, respectively.     

Multi-Residue Determination of Pesticides in Açai Tropical Fruit (Euterpe oleracea) by Matrix Solid-Phase Dispersion Combined with Liquid Chromatography

An extraction method based on matrix solid phase dispersion was developed to determine bromuconazole, fenbuconazole, parathion-methyl, kresoxim-methyl, and teflubenzuron in açai using liquid chromatography with ultraviolet diode array detector. The best results were obtained using 1.0 g of açai, 3.0 g of neutral alumina as the dispersant sorbent, and cyclohexane/ethyl acetate (1:1, v/v, 20 mL) as an eluting solvent. The method was validated using açai samples fortified with pesticides at three concentration levels (0.25, 0.5, and 1.0 mg kg^?1). Average recoveries (seven replicates) ranged from 66 to 119 %, with relative standard deviations between 1.4 and 20 %. The detection and quantification limits for açai ranged from 0.02 to 0.05 mg kg^?1 and from 0.05 to 0.1 mg kg^?1, respectively.     

Estimation of the intake of phenol compounds from virgin olive oil of a population from southern Spain

The objective of the study was to determine the mean polyphenol composition of different varieties of virgin olive oil (VOO) habitually consumed in the region of southern Spain and to estimate the dietary exposure to olive oil polyphenols in that population. There were statistically significant differences in total polyphenols among varieties, with the Picual variety containing the largest amount with a mean value of 591.8 mg kg^–1. The main phenolic compounds found in the VOOs under study were tyrosol and hydroxytyrosol. The highest amounts of both substances were found in Picual olive oils with concentrations of 2.3–6.6 mg kg^?1. The total intake of polyphenols from VOO ranged between 8.2 mg day^–1 (SD = 4.14) for the under 19 year olds and 21.3 mg day^–1 (SD = 3) for the over 50 year olds. Some polyphenols, including tyrosol and hydroxytyrosol, were consumed principally as olive oil. The intake of these compounds in the studied population was in the range of 88.5–237.4 μg day^–1. This has particular importance as recent studies have demonstrated that hydroxytyrosol helps to improve plasma lipids levels and repair oxidative damage related to cardiovascular disease. There was a greater dietary consumption of polyphenols in olive oil among the participants who more closely followed the Mediterranean diet pattern. A higher consumption of olive oil and therefore a greater exposure to polyphenols was observed in females versus males and in participants of normal weight versus those who were overweight. The total intake of polyphenols from VOO significantly increased with higher age, reflecting the greater intake of this oil by older people, who also show a closer adherence to the Mediterranean diet. The over 50-year-old age group showed the greatest consumption of this olive oil and therefore of phenolic compounds, which are healthy protectors in the human diet that contribute to the acknowledged benefits of the Mediterranean diet.     

Oxytetracycline,tetracycline, chlortetracycline and doxycycline in pasteurised cow’s milk commercialised in Brazil

The aim of this study was to investigate the presence of tetracycline residues in pasteurised cow’s milk using high-performance liquid chromatography coupled with UV/VIS detection to determine the exposure of Brazilian’s population to antibiotic residues. One hundred samples collected from the State of Paraná, Brazil, were analysed. Three of these samples were contaminated at the following concentrations: 121.8 µg·kg^?1 for oxytetracycline, 93.5 µg·kg^?1 for tetracycline and 134.6 µg·kg^?1 for chlortetracycline (61.6 µg·kg^?1) and doxycycline (73.0 µg·kg^?1). The median tetracycline residue concentration found in the samples was 42.3 µg·kg^?1, and the estimated daily intake (EDI) was 0.05 µg Kg^?1 bw day^?1 in Brazil. These results demonstrate that the occurrence of tetracycline in Brazilian milk was low (3%) and only for 2% above the maximum residue limit, so the risk to the population from the presence of these residues in milk was low (<1% of the acceptable daily intake).     

Applicability of Pressurized Liquid Extraction for Melamine Analysis in Pet Foods with High-Performance Liquid Chromatography with Diode Array Detection

A pressurized liquid extraction (PLE) method was developed for melamine analysis in pet foods. The PLE method which utilized an accelerated solvent extraction (ASE®) system was also compared with sonication and polytron extraction methods. The parameters for the optimized PLE method were temperature (75?°C for wet pet food, 125?°C for dry pet food), pressure (1,500 psi), static time (10 min), flush volume (40%), purge time (1 min), and number of cycles (1). Recoveries obtained by PLE method were significantly higher (P?≤?0.05) than those of sonication and polytron methods for dry pet food samples. For the analysis of adulterated pet foods, PLE resulted in the highest melamine content followed by sonication and polytron. Using PLE, samples fortified with melamine at 2.5 and 100 mg kg^?1 resulted in recoveries ranging from 55% to 90% for wet samples and from 90% to 116% for dry samples. Low recovery rate from wet samples at low spike level (2.5 mg kg^?1) may have been caused by co-aggregation of polysaccharide and protein with melamine due to low pH during solid-phase extraction cleanup. Limit of detection and limit of quantification values were 0.5 (mg kg^?1) and 1.0 (mg kg^?1) for dry samples. Overall, PLE had the best extraction efficiency compared to sonication and polytron, proving PLE to be a useful tool for melamine analysis of pet foods.     

Migration of selected hydrocarbon contaminants into dry semolina and egg pasta packed in direct contact with virgin paperboard and polypropylene film

Migration of mineral oil saturated hydrocarbons (MOSH), polyolefin oligomeric saturated hydrocarbons (POSH), and polyalphaolefins (PAO from hot melts) into dry semolina and egg pasta packed in direct contact with virgin paperboard or polypropylene (PP) flexible film was studied. Migration was monitored during shelf life (up to 24 months), through storage in a real supermarket (packs kept on shelves), conditions preventing exchange with the surrounding environment (packs wrapped in aluminium foil), and storage in a warehouse (packs inside of the transport box of corrugated board). Semolina pasta packed in virgin paperboard (without hot melts) had a MOSH content lower than 1.0 mg kg^?1. An increasing contamination with PAO belonging to the adhesives used to close the boxes was detected in egg pasta, wrapped in aluminium (1.5 and 5 mg kg^?1 after 3 and 24 months, respectively). An environmental contribution to total hydrocarbon contamination was observed in egg pasta kept on shelves that, after 3 and 24 months, showed levels of PAO/MOSH < C₂₅ around 3 and 10 mg kg^?1, respectively. The migration of POSH from PP film into egg pasta wrapped in aluminium was around 0.6 mg kg^?1 after 3 months of contact and reached 1.7 mg kg^?1 after 24 months of contact. After 9 months of contact, semolina pasta packed in PP film and stored in the transport box showed that some MOSH migrated into the pasta from the board of the transport box (through the plastic film).     

Analysis of mineral oil in food: results of a Belgian market survey

ABSTRACT

Recently, migration of mineral oil components from food contact materials into various foods has been reported. The analysis of mineral oil in food is complicated since it consists of mineral oil saturated hydrocarbons (MOSH) comprising a complex mixture of linear, branched and cyclic compounds and variable amounts of mineral oil aromatic hydrocarbons (MOAH), mainly alkylated. Both MOSH and MOAH form ‘humps’ of unresolved peaks in the chromatograms with the same range of volatility. Since these two fractions have a different toxicological relevance, it is important to quantify them separately. Occurrence data on mineral oil are available only for a limited number of food groups and only from few countries. In Belgium, data on the contamination of food by mineral oil are lacking. In this contribution, an in-house validated online combination of liquid chromatography with gas chromatography (LC–GC) with flame ionisation detection (FID) was used for the quantification of MOSH and MOAH. Totally, 217 packed food samples were selected using a well-defined sampling strategy that targeted food categories which are highly consumed and categories suspected to contain mineral oil. For 19 samples, the method was not applicable. For the 198 remaining samples, MOSH was detected in 142 samples with concentrations up to 84.82 mg kg^?1. For the MOAH fraction, there are 175 samples with a concentration below the limits of quantification (LOQ), while 23 samples had a higher concentration ranging from 0.6 to 2.24 mg kg^?1. Finally, these results were compared with the action thresholds as proposed by the Scientific Committee (SciCom) of the Belgian Food Safety Agency (FAVV-AFSCA). Only one sample exceeded the threshold for MOSH, while the threshold for MOAH was exceeded in 23 samples. For the samples exceeding the action threshold, further investigation is needed to identify the contamination source.     

Validation and quantification of neonicotinoid insecticide residues in rice whole grain and rice straw using LC-MS/MS

An efficient analytical method was developed and validated using a modified QuEChERS method and LC-MS/MS for the detection and quantification of neonicotinoid insecticide residues in rice whole grain and rice straw. The samples were extracted using acetonitrile and cleaned up by dispersive solid-phase extraction. Validation based on five fortification levels showed good recoveries of neonicotinoids ranging from 75% to 116 % and 60% to 105 % for rice whole grain and straw, respectively. The precision ranged between 3% and 17 %, and 2% and 10 % for grain and straw, respectively. The limit of detection was from 0.007 to 0.0084 mg kg^?1 and 0.005 to 0.15 mg kg^?1 and the limit of quantification was in the range of 0.024–0.028 mg kg^?1 and 0.016–0.051 mg kg^?1 for rice whole grain and rice straw, respectively. Monitoring of farm gate samples indicated that, out of 24 samples, 1 rice whole grain sample was contaminated with thiamethoxam residues (0.07 mg kg^?1).     

Cadmium and lead in female cattle livers and kidneys from Vojvodina,northern Serbia

ABSTRACT

Concentrations of cadmium (Cd) and lead (Pb) were determined in livers (n = 52) and kidneys (n = 52) of female cattle (345–2717 days old) from dairy farms in the region Vojvodina. Cd and Pb were analysed by inductively coupled plasma-optical emission spectrometry, after microwave digestion. Cd and Pb concentrations did not exceed the Serbian and European maximum set limits in any sample. The Cd concentrations in the livers and kidneys ranged from 0.033 to 0.151 mg kg^?1 wet weight and from 0.055 to 0.510 mg kg^?1 wet weight, respectively. The corresponding Pb concentrations were 0.015-0.159 mg kg^?1 wet weight and 0.021-0.196 mg kg^?1 wet weight, respectively. Mean Cd and Pb concentrations were significantly lower (p < 0.001) in the liver (0.072 and 0.053 mg kg^?1 wet weight) than in the kidney (0.190 and 0.075 mg kg^?1 wet weight). There were good correlations between Cd in liver and Cd in kidney, Pb in liver and Pb in kidney, Cd level and age and Pb level and age in both tissues.     

Levels of platinum group elements and rare-earth elements in wild mushroom species growing in Poland

Due to limited data-describing abilities of mushrooms to accumulate platinum group elements (PGEs) and rare-earth elements (REEs), the aim of this study was to determine, by inductively coupled plasma optical emission spectrometry followed by microwave-assisted sample digestion by nitric acid, the content of these elements in 20 mushroom species (10 above ground and 10 growing on wood), mostly edible, collected near a busy trunk road. The highest content of PGEs in above-ground mushroom species was observed in Lepista gilva and Suillus bovinus fruit bodies (0.38 ± 0.05 and 0.37 ± 0.03 mg kg^?1 DW, respectively), while in mushrooms growing on wood, the highest content was observed in Pleurotus ostreatus (0.35 ± 0.04 mg kg^?1 DW). The mean content of PGEs for both these groups was 0.23 ± 0.08 and 0.26 ± 0.07 mg kg^?1 DW, respectively. The highest content of REEs in Suillus luteus and Tricholoma equestra was 5.03 ± 0.50 and 2.18 ± 0.56 mg kg^?1 DW, respectively, but within mushrooms growing on wood in Ganoderma applanatum fruiting bodies it was 4.19 ± 0.78 mg kg^?1 DW. Mean contents of REEs were 1.39 ± 1.21 and 1.61 ± 0.97 mg kg^?1 DW in above-ground species and species growing on wood, respectively. Generally, the group of mushroom species growing on wood was capable of slightly higher accumulation of both REEs and PGEs. No limits have been established for both the groups until now.