Mycotoxins produced by Fusarium genus in maize: determination by screening and confirmatory methods based on liquid chromatography tandem mass spectrometry

A confirmatory method for fusariotoxin analysis in maize meal, based on liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS), was developed, and compared with a previously published screening method, based on the same technique. By eluting selectively from a Carbograph-4 clean-up cartridge trichothecenes, fumonisins and macrocyclic lactones, and optimizing LC–MS/MS conditions for every chemical class, a sensitive and reliable determination was performed. Method quantification limits for confirmatory and screening methods were in the range 0.001–0.019 mg/kg and 0.003–0.125 mg/kg, respectively.     

Xylitol crystallization from culture media fermented by yeasts

Among sugar substitutes, an important role is played by xylitol, an aliphatic pentitol provided with some interesting properties which make it a high value product for pharmaceutical, odontological and food industries. Its production by biotechnological methods is based on fermentation of agro-industrial residues and could potentially compete with the traditional chemical way. However, crystallization is an important stage of xylitol production, since in many respects it determines the yield and quality of the target product. In the present work tests were made in order to determine the best conditions to clarify fermented media, which were then subjected to isothermal crystallization in the presence or in the absence of residual xylose and varying xylitol concentration as well as cooling temperature (−10 ≤ T_c ≤ 15 °C). Besides, the kinetics of xylitol crystallization from fermented solutions was investigated as function of the initial solution supersaturation and cooling temperature. The effect of the presence of residual xylose on the rate of crystallization was also evaluated. The best clarifying treatment was found to be 20 g l⁻¹ activated charcoal at room temperature for 1 h. The study of xylitol crystallization revealed the positive effect of the presence of residual xylose, which ensured a 1.6-fold increase in the crystallization yield (from 0.27 to 0.42).     

The PlantLIBRA project: how we intend to innovate the science of botanicals

The main aim of the EC-financed R&D project PlantLIBRA (PLANT food supplements: Levels of Intake, Benefit and Risk Assessment) is to foster the safe use of food supplements containing plants or botanical preparations, by enabling science-based decision making by regulators and stakeholders. To make informed decisions, competent authorities and industry need more accessible and quality-assured information, as well as better tools (e.g., databases) and procedures for safety and benefit assessments, supported by broadly accepted methodologies. Consequently, PlantLIBRA is working to develop, validate and disseminate data and methodologies for risk and benefit assessment of plant food supplements, and to implement sustainable international cooperation. International cooperation will help ensure the quality of botanicals imported in the EU. Moreover, the project will provide data on intake by conducting a harmonized consumption survey. Existing composition and safety data will be collated into a meta-database. New analytical data and methods will be investigated and validated. The consortium is working closely with competent authorities and stakeholders.     

Harmful dinoflagellate Ostreopsis cf. ovata Fukuyo: detection of ovatoxins in field samples and cell immunolocalization using antipalytoxin antibodies

Ostreopsis cf. ovata, a benthic dinoflagellate often blooming along the Mediterranean coasts, has been associated with toxic events ranging from dyspnea to mild dermatitis. In late September 2009, an Ostreopsis cf. ovata bloom occurred in the Gulf of Trieste (Northern Adriatic Sea; Italy), causing pruritus and mild dermatitis in beachgoers. An integrated study was initiated to characterize Ostreopsis cells by light and confocal microscopy, PCR techniques, immunocytochemistry, and high resolution liquid chromatography-mass spectrometry (HR LC-MS). The presence of Ostreopsis cf. ovata of the Atlantic/Mediterranean clade was unambiguously established by morphological and genetic analyses in field samples. Several palytoxin-like compounds (ovatoxin-a,-b,-c,-d,-e) were identified by HR LC-MS, ovatoxin-a being the most abundant (45-64 pg/cell). Surprisingly, no palytoxin was detected. For the first time, monoclonal and polyclonal antipalytoxin antibodies revealed the intracellular cytoplasmic localization of ovatoxins, suggesting their cross-reactivity with these antibodies. Since harmful dinoflagellates do not always produce toxins, the immunocytochemical localization of ovatoxins, although qualitative, can provide an early warning for toxic Ostreopsis cells before their massive diffusion and/or concentration in seafood.     

Simultaneous detection of transgenic DNA by surface plasmon resonance imaging with potential application to gene doping detection

Surface plasmon resonance imaging (SPRi) was used as the transduction principle for the development of optical-based sensing for transgenes detection in human cell lines. The objective was to develop a multianalyte, label-free, and real-time approach for DNA sequences that are identified as markers of transgenosis events. The strategy exploits SPRi sensing to detect the transgenic event by targeting selected marker sequences, which are present on shuttle vector backbone used to carry out the transfection of human embryonic kidney (HEK) cell lines. Here, we identified DNA sequences belonging to the Cytomegalovirus promoter and the Enhanced Green Fluorescent Protein gene. System development is discussed in terms of probe efficiency and influence of secondary structures on biorecognition reaction on sensor; moreover, optimization of PCR samples pretreatment was carried out to allow hybridization on biosensor, together with an approach to increase SPRi signals by in situ mass enhancement. Real-time PCR was also employed as reference technique for marker sequences detection on human HEK cells. We can foresee that the developed system may have potential applications in the field of antidoping research focused on the so-called gene doping.     

Effect of poly(ethylene terephthalate) morphology on thermal cis-trans isomerization and photofading of some azo dyes: A kinetic study

Three poly(ethylene terephthalate) films were prepared having the same crystallinity but different morphology. They were colored with azo dyes XC₆H₄N = NC₆H₄N(C₂H₅)₂ (where X is H, OCH₃, CN, and COOC₂H₅). The kinetics of the thermal cis-trans isomerization of these dyes has been studied below the glass transition temperature in the range 25–56°C. The isomerization process was found to be the result of a multiplicity of first-order reactions. The kinetic parameters have been correlated with the order degree at molecular level of the polymer. Lightfastness of the dyes in the polymer matrices has been also investigated: it appeared to be in relation with the supermolecular structure of the film.     

Genetic analysis of avoidance, maze, and wheel-running behaviors in the mouse.

Conducted a genetic analysis of avoidance, maze learning, and wheel-running activity in 1,573 SEC/1ReJ, DBA/2J, and C57BL/6J strain mice and their F1, F2, and F3 progenies. Results show that the mode of inheritance in a given behavioral measure depends on the crosses considered. Thus, a given allele may be dominant in a given hybrid combination and recessive in another combination. The significant genetic correlations between these 3 behavioral measures suggest that these traits could be influenced by some of the same genes. The estimates of heritability are larger for avoidance than for activity, suggesting that the latter trait is more related to fitness. (36 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of residual water content on the physico-chemical properties of sucralfate dried gel obtained by microwave drying

The purpose of this study was to investigate the physico-chemical characteristics of sucralfate humid gel dried by microwaves, in relation to the residual water content. Differential scanning calorimetry (DSC) allowed for the determination of the water state in sucralfate samples. Fourier-transform infrared (FT-IR) spectroscopy was used to monitor the changes in sucralfate gel structure induced by the microwave drying. A boundary value of total water content for sucralfate gel samples was found at 42% (w/w). Below this value only bound water was present, whereas above this value, the increase in total water was due to free water. In the physical form of gel, the strength of the coordination between sulfate anions and the positively charged aluminum hydroxide was dependent on the residual water content. The study of the sedimentation behavior of water suspensions prepared with dried sucralfate allowed for the evaluation of the retention of gel properties. We found that the microwave drying process affected the sedimentation of sucralfate dried gel suspensions independent of the residual water content: when suspensions were prepared from sucralfate dried gel powders containing more than 42% (w/w) of residual water, the sedimentation ratio was higher than 0.9. The non-gel powder suspension showed a sedimentation ratio of 0.68 ± 0.02, whereas the sucralfate humid gel suspension did not sediment.