Biologically active compounds in tomatoes from various fertilisation systems

The aim of this study was to investigate the effect of way of tomatoes cultivation on content of both health promoting and toxic components representing by carotenoids (lycopene, β-carotene), vitamin C and glycoalkaloids (α-tomatine, dehydrotomatine). The levels of biologically active compounds were shown to be strongly affected by the degree of maturity of fruit and varied among system with various fertilizers. Slurry, organic fertilizer with high fertilization efficiency, is good alternative to mineral fertilization. Lower content of toxic glycoalkaloids was found in tomatoes from organic and combined “low input” farming. The differences were variety depended in some extent

Quality of Organic Food

Otázka kvality bio-produktu se stala vysoce aktuálním tématem. Konzumace biopotravin či produktů systémů s nízkými vstupy syntetických agrochemikálií („low input“) je stále více vnímána jako součást zdravého životního stylu. Obecně lze v takto pěstovaných plodinách očekávat nižší obsah látek pocházejících z chemizace zemědělství, jako jsou rezidua pesticidů, těžké kovy a dusičnany. Předností biopotravin muže být mimo jiné také zvýšený obsah některých živin. Je nutné však konstatovat, že zdravotní riziko z ekologicky pěstovaných potravin není automaticky nulové, za určitých okolností mohou totiž vykazovat zvýšený obsah přírodních toxických látek (napr. glykoalkaloidu), předmětem intenzivních diskusí je i možný vyšší obsah toxických sekundárních metabolitu vláknitých hub – mykotoxinu. Vzrůstající poptávka po biopotravinách se promítá i do potřeby realizace seriozního výzkumu, zaměřeného na posouzení nutriční a hygienicko-toxikologické jakosti produktu ekologického zemědělství. Studie, které porovnávají kvalitu produktů z ekologického a konvenčního zemědělství existují jen v relativně omezeném rozsahu a v mnoha případech se jejich závěry někdy i podstatně liší. Je třeba, aby výzkum v této oblasti objasnil ještě celou radu otázek. Jeho výsledky a závěry by potom mohly pomoci zdokonalit metody, užívané v ekologickém i konvenčním zemědělství pro dosažení vyšší kvality zemědělských produktu. V rámci mezinárodních i národních projektů je na Ústavu chemie a analýzy potravin, VŠCHT Praha, věnována intenzivní pozornost zkoumání kvality, původu (traceability) a pravosti (autenticity) ekologických surovin a produktu

Organic versus conventional potatoes – is there basis for consumers preference?

The aim of this study was to investigate the influence of growing conditions on the quality of potatoes from organic farming systems as compared to that from conventional farming. In our previous study conducted in the years 1996 – 1999 we recognised some differences between the potatoes (Solanum tuberosum) from organic and conventional farming. To demonstrate the general validity of observed trends, follow up study was established in Czech Republic in the years 2002-2005. The ultimate goal of the project was to collate data for the assessment of a potential influence of foods from organic production system on consumers´ health by studying differences between potatoes grown in both systems (for this purpose the levels of potentially toxic compounds as well as nutritionally valuable components with regard to variety, geo-graphical location and inter-annual variation were determined)

BLACK POLYPROPYLENE MULCH TEXTILE IN ORGANIC AGRICULTURE

Black polyethylene mulch is used for weed control in a range of crops under the organic system. The use of black polypropylene mulch is usually restricted to perennial crops. The trial was conducted at Experimental station of Department of Crop Production of the Czech University of Life Science Prague-Uhříněves in Czech Republic. For the experiments were used black polypropylene woven mulch (comparison wit bare soil), two varieties of early potatoes Finka and Katka. Black polypropylene textile was used in potatoes by organic agriculture and it had positive effect on soil temperature (in the depth of 100 mm). Slightly higher soil temperatures under black polypropylene mulch in the vegetation period after planting had favourable influence on earlier stands emergence. The soil water potential (in the depth of 250 mm) and also the soil water content have been beneficial for black polypropylene mulch. Significantly lower values of the soil water potentials have been found in the period after planting and at the end of vegetation. Black polypropylene mulch provided favourable temperatures and soil moisture. Post harvest analyses were focused on the determination of the yield and quality tubers from each variant

Assessing the mycotoxicological risk from consumption of complementary foods by infants and young children in Nigeria

This study assessed, for the first time, the mycotoxicological risks from consumption of complementary foods by infants and young children in Nigeria. Molds belonging to Aspergillus aculeatinus, A. flavus, A. luchuensis, A. tubingensis, A. welwitschiae and Geotrichum candidum were recovered from the complementary foods. Twenty-eight major mycotoxins and derivatives, and another 109 microbial metabolites including chloramphenicol (a bacterial metabolite), were quantified in 137 food samples by LC-MS/MS. Aflatoxins and fumonisins co-contaminated 42% of the cereal- and nut-based food samples, at mean concentrations exceeding the EU limits of 0.1 and 200 μg/kg set for processed baby foods by 300 and six times, respectively. Milk contained mainly beauvericin, chloramphenicol and zearalenone. The trichothecenes, T-2 and HT-2 toxins, were quantified only in infant formula and at levels three times above the EU indicative level of 15 μg/kg for baby food. Chronic exposure estimate to carcinogenic aflatoxin was high causing low margin of exposure (MOE). Exposures to other mycotoxins either exceeded the established reference values by several fold or revealed low MOEs, pointing to important health risks in this highly vulnerable population. The observed mycotoxin mixtures may further increase risks of adverse health outcomes of exposure; this warrants urgent advocacy and regulatory interventions.</p

Analysis of squat shear wall with different dimensions and position of opening under different type of static loads

Shear walls are usually used in high-rise building or building on high frequency of wind area as the structural element to restrain lateral forces. Openings are created on the shear wall for the architecture, ventilation or mechanical and electrical purposes. With the existence of the opening, the strength of the wall is reduced by the reduction in concrete area and the discontinuity of the reinforcement due to opening which may lead to structural failure. The main objective is to study the effect of size and position of the opening towards the structural behavior of the shear wall under different type of static loads. The analysis is done using the software ANSYS12.0. The samples are SW1, SW2, SW3, SW4, SW5, SW6, SW7 and SW8 where SW1 is solid shear wall while SW2, SW3, SW4, SW5, SW6, SW7 and SW8 are shear walls with different size and position of opening. They are analyzed by using 2 different types of loads which are uniformly distributed axial load and uniformly lateral load. From the same magnitude of loads applied towards the shear walls, they are compared by the cracking pattern and the stress distribution. Under both axial and lateral loads, it shows a significance results that the shear wall with greater opening size shows less efficiency. The position of opening further from the support shows a more significance effect towards the strength of the wall from axial load but opposite from the lateral load. Besides, the closer the position of the shear wall to the load, the less efficient it is. As a conclusion from the results, the most suitable position of the opening on the shear wall is further from the support and the loads and it shows that there is a significance effect even from a smallest opening

Proficiency and Interlaboratory Variability in the Determination of Phthalate and DINCH Biomarkers in Human Urine: Results from the HBM4EU Project

A quality assurance/quality control program was implemented in the framework of the EU project HBM4EU to assess and improve the comparability of biomarker analysis and to build a network of competent laboratories. Four rounds of proficiency tests were organized for 15 phthalate and two DINCH urinary biomarkers (0.2-138 ng/mL) over a period of 18 months, with the involvement of 28 laboratories. A substantial improvement in performance was observed after the first round in particular, and by the end of the program, an average satisfactory performance rate of 90% was achieved. The interlaboratory reproducibility as derived from the participants' results varied for the various biomarkers and rounds, with an average of 24% for the biomarkers of eight single-isomer phthalates (e.g., DnBP and DEHP) and 43% for the more challenging biomarkers of the mixed-isomer phthalates (DiNP, DiDP) and DINCH. When the reproducibility was based only on the laboratories that consistently achieved a satisfactory performance, this improved to 17% and 26%, respectively, clearly demonstrating the success of the QA/QC efforts. The program thus aided in building capacity and the establishment of a network of competent laboratories able to generate comparable and accurate HBM data for phthalate and DINCH biomarkers in 14 EU countries. In addition, global comparability was ensured by including external expert laboratories.This study was part of the HBM4EU project receiving funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 733032. Co-funding was received from the Dutch Ministry of Agriculture, Nature and Food Quality (project KB 37-002-014-001/002).S