J. Blesa

Determination of aflatoxins in peanuts by matrix solid-phase dispersion and liquid chromatography ☆

A new method based on matrix solid-phase dispersion (MSPD) extraction was studied to determine aflatoxin B1, B2, G1 and G2 from peanuts. Optimization of different parameters, such as type of solid supports for matrix dispersion and elution solvents were carried out. The method used 2 g of peanut sample, 2 g of C18 bonded silica as MSPD sorbent and acetonitrile as eluting solvent. Recoveries of each aflatoxin spiked to peanut samples at 2.5 ng/g (5 ng/g for aflatoxin G2) level were between 78 and 86% with relative standard deviations ranging from 4 to 7%. The limits of quantification ranged from 0.125 to 2.5 ng/g for the four studied aflatoxins using liquid chromatography (LC) with fluorescence detection. In addition, LC coupled to mass spectrometry with an electrospray interface was used for confirmation of aflatoxins present in real samples. Eleven peanut samples from different countries were analyzed by the proposed method and by using an enzyme-linked immunosorbent assay (ELISA). ELISA test is a good screening method for investigation of these mycotoxins in peanut samples.

Further data on the presence of Fusarium emerging mycotoxins enniatins, fusaproliferin and beauvericin in cereals available on the Spanish markets

In this work, 64 samples of cereals purchased from local markets in the Valencian community (Spain) were investigated for the presence of six emerging mycotoxins: enniatins ENs (ENA, ENA1, ENB and ENB1), beauvericin (BEA) and fusaproliferin (FUS). Samples were extracted with a mixture of water/acetonitrile (85/15, v/v) by using an Ultra-turrax homogenizer. Mycotoxins were then identified and quantified with a liquid chromatography (LC) with diode array detector (DAD). Positive samples were confirmed with an LC-MS/MS. Analytical Results showed that the frequencies of contamination of samples with ENs, BEA and FUS were 73.4%, 32.8% and 7.8%, respectively. ENA1 was the most mycotoxin found and levels ranged from 33.38 to 814.42 mg/kg. ENB levels ranged between 2.23 and 21.37 mg/kg. ENB1 levels varied from 4.34 to 45.94 mg/kg. All samples were free of ENA. BEA levels ranged from 0.51 to 11.78 mg/kg and FUS levels varied between 1.01 and 6.63 mg/kg. It could be concluded from this study that the high contamination levels found especially for ENs could be of a negative impact on the population. This is the first paper on the presence of emerging mycotoxins in cereals available in Spain.

Factors affecting the presence of ochratoxin A in wines.

Ochratoxin A (OTA) are synthesized mainly by different species of Aspergillus and Penicillium being its human toxicological effects reflected in different countries due to the consumption of different foods and beverages such as red, white, rose, and special wines. This review presents an overview of the direct (meteorological conditions, grape cultivation, and wine-making techniques) and indirect (latitude, year of production, use of pesticides, presence of spoilage microorganisms, conditions of storage of the harvested grapes, type of maceration, and conditions of fermentation), factors affecting the presence of OTA in wines.

Limited survey for the presence of aflatoxins in foods from local markets and supermarkets in Valencia, Spain.

Aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2) were extracted by matrix solid-phase dispersion with C18 silica and acetonitrile as the eluting solvent, analysed by liquid chromatography with fluorescence detection and confirmed by liquid chromatography with mass spectrometry using an electrospray interface in 58 samples grouped as cereals, dried fruits, herbs and spices, pulses, snacks, and nuts and nut products collected from local markets and supermarkets in Valencia, Spain. All samples analysed by the proposed method were previously studied with an enzyme-linked immunosorbent assay as a screening protocol for the fast detection of mycotoxins. The samples containing residues (3/58) were hazelnut (0.42 and 0.52 μg kg−1 for AFB1 and AFG1, respectively), nut cocktail (0.29 and 0.47 μg kg−1 for AFB1 and AFG1, respectively) and pinhol (0.30 μg kg−1 for AFG1). Such values were below the legislated maximum residue levels for the European Union.

Evaluation of enniatins A, A1, B, B1 and beauvericin in Portuguese cereal-based foods

Sixty-one samples of Portuguese cereal-based foods were analysed for the occurrence of emerging mycotoxins called enniatins (A, A1, B and B1) and beauvericin. Samples were extracted with a mixture of acetonitrile/water (85/15, v/v) using an Ultra-Turrax homogeniser, and mycotoxins were detected with liquid chromatography coupled to a mass spectrometer. This method was validated and adequate values of recovery (70–103%) and relative standard deviation (<15%) were obtained. Signal suppression/enhancement was studied and matrix-matched calibration used to minimise this effect, but no additional clean-up step was necessary. The mass spectrometer was operated in selected reaction monitoring (SRM) mode and with selected transitions for each compound to quantify and to qualify them. Fifty-nine per cent of samples were contaminated. The percentages of enniatins were 53%, 49%, 44% and 16% for A1, B, B1, and A, respectively, and for beauvericin it was 1.6%. For the total samples, the mean contamination was 30, 24, 15, 2.1 and 0.1 ng g−1 for enniatins A1, B, B1 and A, and beauvericin, respectively. The wheat-based samples showed higher levels and greater prevalence than any other cereals monitored. These results were used to estimate the daily intake of ENs from wheat-based cereal by the Portuguese population. At the same time, the usefulness of this method in the analysis of other important mycotoxins (aflatoxin B1, ochratoxin A, deoxynivalenol, T-2 toxin, fumonisin B1 and zearalenone) was evaluated.

Presence of mycotoxins in sorghum and intake estimation in Tunisia

Sorghum samples (n = 60) from Tunisian markets were analysed for the occurrence of 22 of both traditional and emerging mycotoxins. Samples were extracted with a QuEChERS-like method and mycotoxins were detected by LC-MS/MS. This method was validated and adequate analytical parameters were obtained. All samples had contamination with mycotoxins and several samples had higher contamination levels than European Union legislative limits (MLs). The most frequently found mycotoxins were ENB (100%), OTA (98%), ENA1 (63%), ENB1 (56%), BEA (48%), AFB1 (38%) and STG (33%). Mean contaminations were 30.7, 1.93, 33.2, 51.0, 15.4, 1.49 and 20.5 µg kg–1, respectively. While two samples were contaminated with FB2 and FB3 at mean values of 16.2 and 45.9 µg kg–1, respectively, one sample was contaminated with AFB2 and ZEA at levels of 0.82 and 45.0 µg kg–1, respectively. The results were used to estimate the daily intake of mycotoxins through sorghum consumption with regard to normal consumers (low-risk population) and high consumers such as babies (high-risk consumers) who are facing an alarming situation.

Comparison of three solid‐phase extraction processes in quantification of ciprofloxacin and enrofloxacin in pork meat

Due to strong implications for food safety, control of fluoroquinolones residues in swine meat should be undertaken to verify compliance of the contamination levels with the maximum residue limits recently updated by Commission Regulation (EU) No. 37/2010 of 22 December 2009. Solid-phase extraction is widely used in antibiotic analysis in food of animal origin. In this study, the results of a comparative study using different types of solid-phase extraction columns, HLB, MCX, and MAX, for ciprofloxacin and enrofloxacin analysis, in pork meat, are presented. In addition, diverse sample treatments for defatting, precipitate proteins, eliminate cations, and increase the ionic strength, were used to obtain the most suitable method of analysis. Only the MCXs use followed by liquid chromatography with fluorescence detection resulted in chromatograms that allow the quantification at maximum residue limits. The validation method, in terms of CCα and CCβ, recovery and precision determination, was according to the EU Decision 2002/657/EC. This procedure was used in the analysis of 50 samples of pork meat of Portuguese origin. Only two samples presented residues of enrofloxacin at 30 and 42 μg/kg, values under the legal maximum residue limit.

Extracellular vesicles in food: Experimental evidence of their secretion in grape fruits.

&NA; In the last decade, the number of studies related with extracellular vesicles (EVs) has dramatically grown since their role as key part of intercellular communication has been confirmed. EVs, as transporter of distinct bioactive molecules, can take part in different physiological mechanisms and have been gaining attention as potential tools with a wide range of therapeutic effects. Whereas a high number of studies have been published related to mammalian derived EVs, including products as food source, the existence of EVs in plants still is controversial. Recent descriptions of vesicles derived from edible plants show that they might contain pharmacological active molecules. In this context, EVs from food are attracting increasing interest due to their relevance in modulating cellular processes (involved in health and disease), as well as therapeutic vehicles. The present work aims to summarize the current knowledge on exosomes in foods, actually limited to only four FAO groups (Milk, Starchy roots and tubers, Nuts and seeds, and Fruits). In addition, we have further characterized EVs isolated from grape berry juice by classical differential centrifugation, and described a preliminary dissection of their secretion in vivo. Graphical abstract Figure. No caption available.

Glucose influence on the production of T-2 toxin by Fusarium sporotrichioides.

Toxigenic isolate of Fusarium sporotrichioides was tested for the T-2 toxin production on PDA plates during 10 days under various glucose concentrations. T-2 toxin was determined by LC-MS and confirmed with LC-MS/MS. This analytical method has been applied, for the first time, to an extensive study of T-2 accumulation. Results showed that the production of this mycotoxin is directly correlated to the concentration of glucose present in the medium. Concentrations of T-2 toxin produced by the strain of F. sporotrichioides ranged from 0 to 1.45 mg/kg. The better T-2 production was evidenced in the fermentation operated with 20% of glucose.

Untargeted metabolomics of fresh and heat treatment Tiger nut (Cyperus esculentus L.) milks reveals further insight into food quality and nutrition

Tiger nut (Cyperus esculentus L.) is a crop traditionally grown in Valencia Region (Spain) and other temperate and tropical regions in the world, where its tubers are commonly consumed as tiger nut milk (horchata). Because of their nutritive potential and original taste, these products are beginning to spread internationally and, as consequence, analytical procedures to assess nutritional profiles, quality control issues are acquiring increasing relevance. The main objective of this study was to use an advance analytical method and chemometrics tools to determine if the ultra-high temperature (UHT) treatment necessary to extend the shelf life of tiger nut milk would affect the profile of nutrients when compared to fresh product. A cold solvent extraction followed by liquid chromatography coupled with high resolution mass spectrometry (UHPLC-HRMS) was used. Datasets obtained from UHT and fresh tiger nut milk data were analyzed through an untargeted metabolomics approach to compare chemical patterns, highlighting differences in citric acid esters of mono- diglycerides (CITREM) and monoacylglycerol (MAG) used as emulsifiers of UHT products, and a remarkably higher abundance of biotin, phosphatidic acid (PA) and L-arginine in fresh products. These results showed that untargeted metabolomics through high resolution tandem mass spectrometry allowed fine differences between food products to be found, therefore, the nutrient lost caused by UHT treatment was clearly discerned.