Search

A proper nutrition is crucial for children's healthy development. Regardless of the usual recommendations to follow a varied diet, some foods can be a source of toxic natural contaminants such as mycotoxins, potent secondary metabolites produced by filamentous fungi. In addition to the most well-known mycotoxins, many of which are subject to tight regulation regarding the maximum levels allowed in different types of food, there is a large group of mycotoxins, the so-called emerging mycotoxins, about which less knowledge has already been acquired, which have gradually been the target of interest from the scientific community due to their prevalence in most foodstuffs, particularly in cereals and cereal-based products. Alternariol and his metabolite alternariol mono-methyl ether, beauvericin, citrinin, culmorin, enniatins, ergot alkaloids, fusaproliferin, kojic acid, moniliformin, sterigmatocystin, tentoxin and tenuazonic acid are the most representative of them. The current review gathered the information of the last ten years that have been published on the levels of emerging mycotoxins in food products dedicated for infants and children. European Union countries are responsible for most of the reported studies, which showed levels that can reach hundreds of mg/kg.

The objective of the present study was to investigate the impact of phenolic-rich avocado peel extract (APE) as an ingredient in beef and soy-based burgers to increase their antioxidant activity, reduce lipid and protein oxidation during gastric digestion, and inhibit urease and anhydrase carbonic activity, which are considered as key factors in the main steps of Helicobacter pylori adhesion in the stomach. The gastric bioaccessible fraction of soy and beef burgers with added 0.5% APE obtained by in vitro digestion exhibited a higher content of phenolic compounds, including monomeric and oligomeric (epi)catechin forms and quercetin, and reduced levels of thiobarbituric acid-reactive substances (TBARS) and carbonyls (49% to 73% and 57% to 60%, respectively) when compared with control burgers. Moreover, the burgers with APE inhibited urease and carbonic anhydrase activity. Results generally showed that including APE reduces the primary risk factors associated with H. pylori infection.

The capacity of skimmed milk to neutralise increased reactive oxygen species (ROS) and to attenuate nitric oxide (NO) production, as well as to present cytoprotective effect at the intestinal level was assessed after in vitro gastro-intestinal digestion. The impact on ROS modulation was evaluated at a non-cytotoxic concentration of hydrogen peroxide (H2O2) in a co-culture of Caco-2 and HT-29 intestinal cells. In parallel, a cytotoxic concentration of H2O2 was used to study the effect of digested milk against induced cell apoptosis. Concerning induced NO production, it was evaluated using the model lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. Results showed that digested milk prevented the increase of basal ROS level in the intestinal epithelium and attenuated NO production by LPS-stimulated macrophage cells. In the H2O2-induced cytotoxicity assay, digested milk had no protection against apoptosis, confirmed by the failure in attenuating activated caspase-3/7.

Excessive angiogenesis favours cancer development, allowing cancer invasion. Polyphenols are promising chemopreventive agents, although data gather so far in respect of anthocyanins, namely cyanidin-3-O-glucoside and delphinidin-3-O-glucoside (DG) and respective aglycones are scarce. The capability of these compounds to prevent tumour progression by inhibiting angiogenesis/cell migration/proliferation was studied in: (i) chicken embryo chorioallantoic membrane assay; (ii) MDA-MB-231/MCF-12A cells to study proliferation and vascular endothelial growth factor receptor-2 (VEGFR-2) expression and cytoskeleton dynamics; (iii) in vitro assay to evaluate gastrointestinal digestion. The studied compounds promoted alterations on actin re/disassembly to form protrusions/stress fibres, evidencing capability to disrupt actin cytoskeleton dynamics and inhibiting angiogenesis, at least in part, by VEGFR-2 downregulation, with DG presenting the higher effect. Anthocyanin evidenced selectivity towards cancer cells by eliciting cytotoxicity on MDA-MB-231 cells and having a slight effect on healthy cells. Thus, DG evidenced the most promising profile as dietary supplement to achieve the biological desired effects.

Food contaminants are usually studied as isolated molecules, not considering the overall meal components. Notwithstanding, contaminants are not ingested individually, therefore their risks should be assessed in the context of the overall diet. In the present study the influence of three well known dietary patterns, Western (W), Mediterranean (M) and vegetarian (V), on the bioaccessibility and intestinal transport of polycyclic aromatic hydrocarbons (PAHs) (benzo[a]pyrene (BaP) and benzo[b]fluoranthene (BbF)), heterocyclic aromatic amines (HAAs) (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and 2-Amino-9H-pyrido[2,3-b]indole (AAC)) and mycotoxins (MY) (aflatoxin B2 (AB2) and ochratoxin A (OTA)) was evaluated. Whole meals representative of W, M and V patterns were spiked with 100 µg kg-1 of each contaminant and subjected to the Infogest in vitro digestion method. Intestinal transport was performed using Caco-2 cells in apical/basolateral inserts. Contaminants were quantified by QuEChERS/HPLC/Fluorescence analysis. The dietary pattern itself influenced significantly the bioaccessibility of some contaminants, since higher bioaccessibility of HAAs (PhIP and AAC) was observed for V diet, while higher bioaccessibility of PAHs (BBF and BAP) and the MY (OTA) was observed for W diet. Concerning intestinal transport, the effect of the diet matrices was less noticed. Notwithstanding, AAC transport increased with W diet, while AB2s transport increased with the V diet. Regarding PAHs the three patterns either blocked (BbF) or reduced (BaP) the transport. Besides the well known nutritional, protective or deleterious effects of the different dietary patterns, the increased bioaccessibility or intestinal transport of some food contaminants, can have an additional influence on the global health impact. Highlights: Dietary pattern influenced the bioaccessibility of some studied food contaminants; The impact of dietary pattern on intestinal transport was less notorious; Dietary pattern affects contaminants bioaccessibility/absorption and health. M. A. Faria acknowledges Fundação para a Ciência e a Tecnologia and Norte-01-0145-FEDER-0001 the researcher contract. This work was financed by FEDER - Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020 - Operational Programme for Competitiveness and Internationalisation (POCI), and by Portuguese funds through FCT - Fundação para a Ciência e a Tecnologia in the framework of the project PTDC/SAU-NUT/30322/2017. info:eu-repo/semantics/publishedVersion

The impact of six culinary practices - oven/microwave combined with/without seasoning with oregano/beer - on lipid and protein oxidation of chicken burgers after cooking and after in vitro digestion was assessed. Five oxidation markers - malondialdehyde (MDA), 4-hydroxy-2-nonenal (HNE), hexanal (HEX), carbonyls, and Schiff bases - as well as free amino acids and total fatty acids content were measured. Oregano prevented MDA, HEX, and HNE formation during cooking, while beer seems not to influence their formation. After in vitro digestion, MDA, carbonyls, and Schiff bases increased, regardless of the culinary practice, while HNE and HEX values were reduced. Globally, cooking with oregano exhibited the lowest losses of PUFAs and formation of all oxidation markers, thus it should be used as a mitigation strategy to avoid the formation of oxidation products during cooking, as well as to prevent their formation during in vitro digestion.

Environmental health is increasingly compromised by persistent toxic substances, which may have serious implications in food safety and, thus, in human health. Polybrominated diphenyl ethers (PBDEs) are anthropogenic contaminants with endocrine disruption abilities and are commonly found in seafood, the main route of human exposure. Growing evidence points out that the human gut microbiota interacts with xenobiotics, which may lead to impairment of host homeostasis if functions of microbiota become compromised. The aim of this study was to ascertain if the physiological balance of human gut microbiome is affected by the presence and degree of exposure to PBDEs. Fermentation was performed in a batch closed-system using an inoculum made from fresh human stool. The volatolomic profile was analysed by solid-phase microextraction coupled to gas chromatography-mass spectrometry. Mesophilic, Gram-negative bacteria and coliforms were quantified by classic plating methods. Changes in the gut microbiome were evaluated after DNA extraction followed by deep sequencing of the 16S rDNA region. The exposure to PBDEs resulted in an imbalance in sulfur, short-chain fatty acids and aromatic organic compounds, changing the microbial volatolome in a dose- and time-dependent manner. Slight deviations in the microbial structure of human gut occurred in the presence of PBDEs, especially for high doses of exposure. For the first time, the impact of PBDEs on the microbial homeostasis of human gut microbiota was taken into consideration, revealing noteworthy modifications with serious health implications even at oral exposure doses considered as safe by worldwide regulatory entities. The research leading to these results received financial support from FEDER (Programa Operacional Competitividade e Internacionalização - COMPETE 2020), from PIDDAC through FCT/MCTES project POCI-01-0145-FEDER-028708 and from UID/QUI/50006/2019 with funding from FCT/MCTES. Rebeca Cruz thanks to FCT for the PhD grant SFRH/BD/101945/2014. António Marques thanks to FCT IF program. Miguel Faria acknowledges FCT the researcher contract. Sara C. Cunha also acknowledges FCT for the IF/01616/2015 contract.

Xanthohumol, isoxanthohumol, α and β-acids and iso-α-acids from hops exhibit beneficial properties with promising effects in cancer therapy, however information regarding their effects on colon Caco-2 cells is missing. Herein these compounds and a beer base matrix were tested for antiproliferative activity in the referred cells. Xanthohumol did not show antiproliferative activity at concentrations from 0.313 to 20 µg/mL. Isoxanthohumol was able to inhibit proliferation by 25% at 10–20 µg/mL when pure solution and increase 7–13% the activity of the matrix when spiked. α and β-acids and iso-α-acids, presented IC50 values of 16.16 ± 3.11 and 50.61 ± 13.08 µg/mL, respectively. A synergist effect with the beer matrix was noticed for α and β-acids and iso-α-acids which increased the activity by 36% and 23% at 80 and 100 µg/mL, respectively. The antiproliferative effects of the beer matrix components are thus dependent on both brewing process and hops addition.

The impact of culinary practices – oven or microwave cooking combined with herbs and/or beer – on antibacterial and coccidiostat drugs stability and bioaccessibility in chicken meat was evaluated. Fourteen compounds from 6 classes (β-lactams, tetracyclines, sulfonamides, fluoroquinolones, macrolides, and coccidiostats) were monitored after cooking and in vitro digestion (INFOGEST protocol) at two fortification levels. Depending on their reduction, the presence of transformation products derived from cooking or digestion was investigated. In general, compounds were stable during cooking except amoxicillin, chlortetracycline and tylosin (reductions > 50%). Molecular rearrangement and dechlorination reactions are the most probable transformations derived from cooking. Adding herbs/beer does not benefit their reductions. During in vitro digestion, maximum bioaccessibilities of 60% were observed for all quantified compounds. As drugs and bile salts interact, increasing the absorption of lipophilic drugs, their bioaccessibility predictions must not be based only on the determination of their free form using LC–MS/MS.

The practice of dry-hopping has been used by the brewing industry to obtain beers with increased contents of flavor and bitterness compounds. Notwithstanding this, other compounds such as α-acids (AA) and xhanthohumol (XN) are co-extracted influencing the final characteristics of the beer, particularly its beneficial bioactivity. In this context a model for the understanding of AA and XN extraction by dry-hopping is proposed. The varieties Chinook (CHI), East Kent Goldings (EKG) and Tettnanger (TET) were assayed and robust statistical approaches were applied for data interpretation. Concentration of AA in beers post-maturation reached values higher than 20 mg/L using 2.8 g/L of CHI hops and 10 days of maturation. For XN, a similar behavior was verified. The maximum efficiency of AA and XN extraction (transfer rate) were reached at 13.5 days with dose rates of 147 and 13.9 mg/L, respectively. Authors are grateful to the project UID/QUI/50006/2013-POCI/01/0145/FEDER/007265 with support from FCT/MEC through national funds and co-financed by FEDER, under the Partnership Agreement PT2020. M. A. Faria is grateful for research contract from NORTE-01-0145-FEDER-000011 – FoodNanoHealth and A. Melo wishes to thank the Fundação para a Ciência Tecnologia for grants SFRH/BPD/86898/2012. info:eu-repo/semantics/publishedVersion

Mycotoxins can contaminate poultry production via fungal infection of feeds. The impact of different cooking methods on mycotoxins stability and bioaccessibility is scarcely studied. Recent cooking practices such as the use of roasting bags along with some seasonings to cook chicken have become a trend to maintain the tenderness of the meat. This study evaluated the impact of oven roasting and microwaving of chicken breast muscles, with/without roasting bags and/or herbs addition on the stability and bioaccessibility of the 10 prevalent mycotoxins. Cooking itself reduced mycotoxins content, while using bags did not confer any advantage; adding herbs reduced mycotoxins content by up to 60%, but also appeared to increase their bioaccessibility. Thus, strategies to reduce their increased bioaccessibility should be the subject of future research. Notwithstanding, adding herbs prior to cooking could be used as a mitigation strategy to reduce mycotoxins in meat.

Aflatoxin B1 (AFB1), deoxynivalenol (DON), fumonisin B1 (FB1) and ochratoxin A (OTA) are toxic fungal metabolites co-occurring naturally in the environment. This study aimed to evaluate the toxicological interactions of these mycotoxins concerning additive, antagonistic and synergistic toxicity towards human cells. The theoretical biology-based Combination index-isobologram method was used to evaluate the individual and binary effect of these toxins and determine the type of the interaction using as models Caco-2 (intestinal) and HepG2 (hepatic) cells. Cytotoxicity was assessed using the MTT test at the concentrations of 0.625–20 μM for all the compounds. DON exerted the highest toxicity toward both cells, OTA and AFB1 also showed a dose-effect response, whereas no toxicity was verified for FB1. Synergism or antagonism effects occurred when exposing AFB1-DON and AFB1-OTA on Caco-2 cells at higher or lower concentrations, respectively; while DON-OTA showed synergism throughout all inhibition levels. Concerning HepG2, AFB1-DON exerted a strong synergism, regardless of the level; whereas AFB1-OTA had slight synergism/nearly additive effect; and, OTA-DON had a moderate antagonism/nearly additive effect. Synergistic strengths as high as a dose reduction index of 10 for AFB1-DON were observed in hepatic cells. Taken together our findings indicate that the toxicological effects differ regarding the type of mycotoxins used for combinations and the stronger synergistic effect was observed for mixtures containing DON in both cells. Therefore, even though DON has not been classified as to its carcinogenicity to humans, this mycotoxin may present a serious threat to health, mainly when co-occurring in the environment.

In this study, patulin levels in apples and tomatoes obtained in conventional and organic farms with 0 and 100% of rotten area, were determined by gas chromatography–mass spectrometry (GC–MS) to assess the influence of the production system with patulin content. Additionally, mould species were isolated and identified using classic morphological techniques and a DNA barcode system based on nrITS, β-tubulin and calmodulin genes. The most frequently isolated genera were Rhizopus , Mucor , Alternaria , Cladosporium , Botrytis , Aspergillus and Penicillium . Higher patulin levels were found in samples contaminated by Penicillium expansum . Patulin levels were not significantly different in samples obtained from the two production system (conventional and organic). Among the three studied apple varieties, Golden delicious was the most contaminated with patulin followed by Reineta. Fuji apples with 0 and 100% of rotten area did not present quantifiable patulin levels. A survey for first time realized in commercialized tomato products showed that 35.7% of the samples (10 of 28) contained patulin in levels ranging from 3.22 to 47.72 μg/kg. In apple juices, patulin levels ranged from 1.86 to 45.47 μg/kg, which is below the maximum legal requirement (50 μg/kg).

Aflatoxin B1 (AFB1), deoxynivalenol (DON), fumonisin B1 (FB1), and ochratoxin A (OTA) are prevalent mycotoxins co-occurring in food, and their oral intake is conceivable to occur in the gastrointestinal epithelium. The intestinal absorption of some mycotoxins has been studied but only considering their isolated intake, while their gastric absorption in humans has not been explored. This study evaluated the bidirectional in vitro transport of four mycotoxins, isolated and in mixture, across gastric NCI-N87 and intestinal Caco-2 monolayers. AFB1 and DON were bidirectionally transported, more rapidly for AFB1; whereas OTA and FB1 were only transported in the absorptive direction, the first in both monolayers, and the second only in the gastric epithelium. The mixture of four mycotoxins exhibited some differences in cell uptake/excretion ratios. AFB1 presented the highest fraction absorbed (>96%) isolated and in mixture, followed by DON (72.8 and 82.9%); and OTA (11 and 66%) when transported isolated and in mixture, respectively. Different absorptive patterns on both epithelia were found when mycotoxins are transported isolated or in mixture. Further investigation on combined ingestion of toxins and their mixed transport should be considered for the proper evaluation of human absorption and toxicity of those mycotoxins considering their frequent co-occurrence and consequent co-exposure.

This study presents the results of the identification and quantification of 12 isoflavones (prunetin, irilone, pseudobaptigenin, glycitein, daidzin, genistin, daidzein, pratensein, puerarin, biochanin A, formononetin and genistein) in 23 species of Trifolium (T. arvense, T. pratense, T. ligusticum, T. striatum, T. lappaceum, T. angustifolium, T. hirtum, T. subterraneum, T. isthmocarpum, T. stellatum, T. mutabile, T. strictum, T. fragiferum, T. alexandrinum, T. tomentosum. T. nigrescens subsp. petrisavii, T. nigrescens, T. glomeratum, T. subterraneum subsp. brachycalycinum, T. cherleri, T. resupinatum, T. campestre and T. repens). Isoflavones were extracted by an MSPD method and analyzed with HPLC coupled with a diode-array detector. The evaluation of molecular phylogeny of the IFS gene and the relation with isoflavone content was also performed. Five species (T. subterraneum subsp. brachycalycinum, T. alexandrinum, T. pratense, T. subterraneum and T. lappaceum) were identified with high levels of biochanin A (431–83 mg/kg), formononetin (72–365 mg/kg) and genistein (9–509 mg/kg), which could be utilized as alternative sources for the nutraceutical industry. Genetic phylogeny for the IFS gene was found in the species studied, with 20 out of 23 species having been divided into two clades, while the remaining three were genetically distant. Based on our results, we confirm the direct correlation between IFS gene polymorphism and isoflavones content in species of Trifolium particularly noted for formononetin. Therefore, the IFS gene can be utilized for screening Trifolium genotypes for formononetin. The relation of the three isoflavones' contents and the molecular phylogeny of plants determined by the IFS sequences, as a screening marker for plants with high isoflavone contents in Trifolium species, are to the best of our knowledge described for the first time.

Isoflavones have been associated with several health protective effects. In this work spontaneous legume plants were screened as putative sources of dietary isoflavones. A molecular identification of the collected species was performed throughout DNA barcoding using ITS, rbcL, rpoC1 and matK sequences. The use of a multi-locus barcoding system complemented with basic morphological information allowed the unequivocal identification at the species level of 90% of the samples. The determination of isoflavone content was performed by high-performance liquid chromatography with diode-array detection. Total average contents in the studied species were significantly different, Ononis natrix and Cytisus scoparius possessing the highest total isoflavones content (396 and 273 mg kg(-1), respectively) and Lotus creticus, the lowest (20 mg kg(-1)). The correlation of total isoflavone content with the phylogeny of this set of plants as determined by the rpoC1 sequences was evaluated for the first time.

A B S T R A C T A faster and more robust version of a previously developed method based on ion-pair extraction, acylation with isobutylchloroformate and gas chromatography–mass spectrometry (GC–MS) analysis for determination of 4-(5-)methylimidazole (4-MeI) in soft drinks and dark beer is proposed. The performance of the method was evaluated in terms of linearity (r always > 0.998); recovery (90–101%, 3 levels); and precision (3–8%, 3 levels, n = 6). Limits of detection and quantification in the matrices studied were 0.60 mg/L and 2.2 mg/L, respectively. The optimized method was applied to a wide variety of soft drinks (brand name and generic colas, uncarbonated flavor and energy drinks) and dark beers (lager, ales trappist, ales-stout, weissbier). Overall, soft drinks presented higher amounts of 4-MeI (ranging from 37 to 613 mg/L) than those found in the dark beers (ranging from 3 to 424 mg/L), with colas presenting the highest levels. When the different colas analyzed were compared, the 4-MeI levels in generic colas were generally higher than those in brand-name colas. 4-MeI was found in only one of eight energy drinks studied. Based on available consumption patterns, consumer exposure to the maximum 4MeI given by the soft drinks was 2.3 and 5.7 mg/kg body weight/day, in Europe and the United States, respectively.

Near infrared spectroscopy (NIRS) may constitute a powerful tool for in-line monitoring of morphological properties of PVC particles in suspension polymerizations. It is shown that dynamic trajectories of morphological properties, as predicted with NIR-based calibration models, change smoothly along the batch; thus, these trajectories can be used as references for process monitoring and control. It is also shown that modification of operation variables during the batch leads to modification of the final morphological properties of the powder. This indicates that the morphology of PVC grains can be manipulated along the batch and that advanced NIR-based control procedures can be implemented for control of the morphological properties of PVC resins, as illustrated through simulation.

It is demonstrated that during suspension polymerizations it is possible to monitor morphological characteristics of PVC resins such as bulk density, cold plasticizer absorption and average particle diameter in-line and in real time using NIR spectroscopy. NIR spectra are obtained at different experimental conditions, showing that the spectra are sensitive to changes in the PVC properties. Standard mathematical procedures (partial least squares regression) are used to build empirical models and correlate the morphological properties with the obtained NIR spectra, allowing for monitoring of the PVC morphology in-line and in real time.

A reliable gas chromatographic mass spectrometric method has been validated for the determination of trace levels ( −1 ) of patulin in apple products and quince jam. The method was based on extraction of patulin with ethyl acetate-hexane, alkalinisation and silylation with N,O -bis-trimethylsilyltrifluoroacetamide with 1% of trimethylchloro-silane. The accurate determination of patulin was achieved by employing commercial 13 C 5–7 patulin labelled as an internal standard, which allowed compensating target analyte losses and enhancement or suppression matrix effects. Limits of detection and quantification of method using real samples were 0.4 and 1.6 μgkg −1 , respectively. Recoveries of patulin from samples spiked at 8–50 μgkg −1 levels ranged between 71% and 89%. The repeatability of measurements (expressed as relative standard deviation) was lower than 16%. The method was successfully applied to the determination of patulin in apple fruit and apple products including juice, cider and baby food, and also in quince fruit and quince jam. A new PCR system for the detection of Penicillium expansum in samples containing highly degraded DNA was developed which permitted the detection of the mould in 2/3 of the samples containing patulin, including juices and jams.

Nicotinic receptor (nAChR) subtypes involved in pre- and postjunctional actions underlying tetanic fade were studied in rat phrenic-nerve hemidiaphragms. We investigated the ability of subtype-specific nAChR antagonists to depress nerve-evoked contractions and [(3)H]-acetylcholine ([(3)H]-ACh) release. Muscle tension was transiently increased during brief high frequency trains (50 Hz for 5 sec). The rank potency order of nAChR antagonists to reduce tetanic peak tension was alpha-bungarotoxin > d-tubocurarine >> mecamylamine > hexamethonium. Reduction of maximal tetanic tension produced by dihydro-beta-erythroidine (0.03-10 microM), methyllycaconitine (0.003-3 microM), and alpha-conotoxin MII (0.001-0.3 microM) did not exceed 30%. Besides reduction of peak tension d-tubocurarine (0.1-0.7 microM), mecamylamine (0.1-300 microM), and hexamethonium (30-3,000 microM) also caused tetanic fading. With alpha-conotoxin MII (0.001-0.3 microM) and dihydro-beta-erythroidine (0.03-10 microM), tetanic fade was evident only after decreasing the safety factor of neuromuscular transmission (with high magnesium ions, 6-7 mM). The antagonist rank potency order to reduce evoked (50 Hz for 5 sec) [(3)H]-ACh release from motor nerve terminals was alpha-conotoxin MII (0.1 microM) > dihydro-beta-erythroidine (1 microM) approximately d-tubocurarine (1 microM) > mecamylamine (100 microM) > hexamethonium (1,000 microM). When applied in a concentration (0.3 microM) above that producing tetanic paralysis, alpha-bungarotoxin failed to affect [(3)H]-ACh release. Data obtained suggest that postjunctional neuromuscular relaxants interact with alpha-bungarotoxin-sensitive nicotinic receptors containing alpha1-subunits, whereas blockade of neuronal alpha3beta2-containing receptors produce tetanic fade by breaking nicotinic autofacilitation of acetylcholine release.

A method for the determination of adenosine, cytidine, uridine, guanosine and inosine 5′-monophosphates in milk and dairy products was optimized and its performance evaluated. The technique was based on ion-pair reversed-phase HPLC separation of the nucleotides and diode array detection. The chromatographic separation was achieved using a C18 column and a gradient elution with a mixture of two solvents: solvent A, water/glacial acetic acid/tetrabutilammonium hydrogensulphate (TBAHS) and solvent B, methanol/glacial acetic acid/TBAHS. The effluent was monitored using a Diode Array detector set at 260 nm. Validation of the proposed method was carried out by standard additions method, with recoveries of 98.3%. The precision of the method was also evaluated and reported a coefficient of variation (CV) as less than 3.2. Upon development the technique was applied on different dairy products in order to study the distribution of nucleotides therein. The samples included bovine, ovine and caprine milks, the corresponding manually manufactured cheeses, whey cheese and whey. Three commercial cheeses made from bovine, ovine and caprine milks, respectively, and 20 infant formulae were also analysed. In contrast to their absence in cheese upon preparation nucleotides were present in cheese at the end of ripening; this observation led to the extraction of DNA in order to evaluate whether nucleotides were released from degradation of nucleoproteins.

This paper describes a procedure performed by high performance liquid chromatography/UV detection for quantification of the major carboxylic acids in table olives (lactic, acetic, succinic, and citric acids); derivatization of carboxylic acids with O-(4-nitrobenzil)-N,N′diisopropylisourea (PBNDI) was performed. The sample preparation involved deproteination with ethanol and the use of strong cation-exchange resin (Dowex 50W-X8) to liberate the free carboxylic acids. The same resin was used to remove the excess of derivatizing reagent. The chromatographic separation was achieved using reverse-phase column C18(ODS). The mobile phase used was a gradient of water and acetonitrile at a flow-rate of 1 mL/min. The effluent was monitored using a UV detector at 265 nm. The method allowed for well-resolved peaks of lactic, acetic, succinic, and citric acids in less than 25 min. Precision and recovery assays were performed with good results for the acids under study. Nineteen samples of table olives available on the...

A simple, reliable, and sensitive gas chromatography-mass spectrometry method for the quantification of volatile and nonvolatile biogenic amines in Port wines and grape juices was developed and evaluated. The method was based on a previously reported two-phase derivatization procedure with isobutyl chloroformate in a toluene medium, which provides a quantitative reaction in 10 min. Following the derivatization step, the excess of reagent was eliminated by treatment with alkaline methanol. The derivatization procedure was performed directly on 1 mL of sample, avoiding any fastidious and time-consuming cleanup extraction steps. The method allows the simultaneous quantification of 22 amines, which can be found in wines: methylamine, dimethylamine, ethylamine, diethylamine, propylamine, isopropylamine, butylamine, isobutylamine, amylamine, isoamylamine, 2-methylbutylamine, hexylamine, pyrrolidine, piperidine, morpholine, 1,3-diaminopropane, putrescine, cadaverine, 1,6-diaminohexane, 2-phenylethylamine, histamine, and tyramine. Because of the fact that histamine and tyramine derivatives are degraded during the isobutyl chloroformate elimination step, the corresponding determination was made after removal of the excess of derivatizing reagent by evaporating an aliquot of the toluene layer obtained after the reaction. The presented method showed excellent analytical characteristics in what linearity, recovery, repeatability, and limit of detections were respected. It was used to assess the concentration of biogenic amines in juice grapes and Tawny and Vintage Port wines with different aging times. On the whole, the total content of amines in Port wines was low. Most of the amines found in wines have their origin in the raw material used for their elaboration, so the Port winemaking process is not prone to the production of this kind of compounds. Total biogenic amine contents have shown a decrease with the aging of both types of Port wines.

This article introduces the use of in-line and in situ monitoring of the dynamic evolution of PVC morphological properties in suspension polymerization reactions based on near infrared spectroscopy (NIRS) intended for control applications. It is shown for the first time that it is possible to follow the dynamic evolution of morphological properties (such as the bulk density, BD, and the cold plasticizer absorption, CPA) in real time. The obtained results indicate that closed-loop control schemes can be properly implemented to control end-use resin properties, which depend upon the morphology of PVC polymer particles. Suspension polymerization of vinyl chloride performed in bench and pilot scale showed that process variables, such as the agitation speed and the amount of suspending agents) can be successfully manipulated in order to control the morphological parameters of PVC resin. Based on this information, a control scheme for these parameters is proposed.

The monitoring of polymer properties is frequently performed through sampling and off-line measurement of quality parameters in lab scale. Because of the long time required to perform off-line analyses, off-line data are generally inadequate for control purposes. As impurities cannot be detected in-line and can exert significant influence on the polymerization kinetics, modifications of some important quality parameters (such as the morphological characteristics of PVC particles) can only be detected at the end of the polymerization, causing major production losses. In the present work it is shown for the first time that it is possible to monitor some of the morphological properties of PVC (such as the bulk density, BD, the cold plasticizer absorption, CPA, and the average particle diameter Dp) in situ and in real time with the help of near infrared spectroscopy (NIRS) in suspension polymerization processes.

We must be careful not to rush to label glyphosate as excessively toxic to humans because when used properly and in proper quantities it is probably no more dangerous and toxic than other effective herbicides on the market. Unfortunately, most effective herbicides and insecticides could be classified as neurotoxic and carcinogenic because in high enough concentrations they can be toxic to biological systems. In their lengthy treatise, “Glyphosate, pathways to modern diseases III: Manganese (Mn), neurological diseases, and associated pathologies” recently published in Surgical Neurology International, Drs. Samsel and Seneff blame the widely used herbicide glyphosate for a number of ecological as well as medical disorders via Mn metabolism and a myriad of other pathophysiological mechanisms.[9] The linking of this effective herbicide to the alphabet soup list of conditions enumerated by the authors seems to be “shotgun science” — namely, multiple associations based on population-based statistics, disconnected correlations, and manipulation of numbers and conditions that create an epidemiological recipe for errors and nonvalid associations. The authors link every kind of disorder imaginable to a widely used chemical that has not been specifically linked clinically to any of those disorders.[9]

Purpose: Adenosine fine-tuning regulates cardiovascular function. The negative chronotropic effect of adenosine depends on the activation of the most abundant adenosine receptor in the heart, the A1AR, leading to GIRK/Kir3.1/3.4 channels opening in the SA node. The A1AR-mediated responses in the atrial muscle also depend on KCa2/SK channel function (unpublished observations). Since these channels are involved in atrial repolarization and in human rhythm disturbances, we aimed at studying the interplay between A1AR and SK channels both in situ and single-cell preparations of rat atria. Methods: Isometric contraction experiments were performed on isolated spontaneously beating atria from Wistar rats. For whole-cell voltage-clamp recordings, atrial myocytes were enzymatically isolated by retrograde perfusion. Immunolocalization studies (A1AR, GIRK1, KCa2.2 and KCa2.3) were evaluated by confocal microscopy. The SA node was identified as a connexin-43 low / neurofilament-160 high immunoreactive region. Results: The selective A1AR agonist R-PIA (0.001-1μM) decreased atrial chronotropism and inotropism in concentration-dependent manner. However, the negative chronotropic effect of R-PIA (IC50~0.03 μM) was evidenced at much lower (~30 times) concentrations than the negative inotropic action (IC50~1 μM). Selective blockade of A1AR and of GIRK/Kir3.1/3.4 channels, respectively with DPCPX (100 nM) and tertiapin Q (300 nM), significantly attenuated the effects R-PIA. Blockade of KCa2/SK channels with apamin (30 nM) potentiated the negative inotropic response of R-PIA, without affecting atrial rate. Apamin-induced atrial sensitization to R-PIA was not observed with other cardiodepressant agents, namely oxotremorine (0.01-3 μM). Voltage-clamp experiments demonstrated that adenosine, via A1AR, plays a dual role in atrial cardiomyocytes by activating inwardly rectifying GIRK/Kir3.1/3.4 and inactivating outward Ca2+-activated KCa2/SK currents upon cell depolarization. Immunolabelling of A1AR, KIR3.1, KCa2.2 and KCa2.3 was observed throughout the right atria. Conclusion: Data demonstrate for the first time that A1AR has opposing effects on distinct K+ currents operating atrial repolarization. While A1AR activation favors the opening of inwardly rectifying GIRK/KIR3.1/3.4 channels modulating atrial automatism, it may also inactivate outward KCa2/SK currents. Taking into consideration that KCa2/SK channel dysfunction has pro-arrhythmic effects drugs targeting the A1AR for supraventricular tachycardia must be used with caution as they might precipitate atrial arrhythmias.

0308-8146/$ - see front matter 2009 Elsevier Ltd. All rights reserved.doi:10.1016/j.foodchem.2009.08.004DOI of original article: 10.1016/j.foodchem.2008.11.074* Corresponding author. Tel.: +351 222078910; fax: +351 22203977.E-mail address: sara.cunha@ff.up.pt (S.C. Cunha).Food Chemistry 119 (2010) 430

A case of Arnold-Chiari malformation (Chiari type II) is reported to describe the usefulness of metrizamide cisternography in the diagnosis and management of this condition.

✓ A technique involving the combined use of Amipaque (metrizamide) and computerized tomography scanning is described for the evaluation of ventriculoperitoneal and ventriculoureteral shunt function. The results of three illustrative cases from a series of nine patients are given. In five patients, the technique demonstrated obstruction that was later confirmed at surgery. In the other four patients, it showed patency in the shunt system, and no surgery was performed, thereby obviating unnecessary shunt revisions.