Threat or treat: Exposure assessment and risk characterisation of chemical contaminants in soft drinks and chocolate bars in various Polish population age groups

In the frame of the European Food Risk Assessment (EU-FORA) fellowship programme, two studies on chemical contaminants in food matrices were carried out in Warsaw, Poland, at the Department of Food Safety and Chemical Analysis, Institute of Agricultural and Food Biotechnology. The first study addressed health concerns about the dietary exposure to bisphenol A (BPA) contamination due to consumption of soft drink by Polish population. BPA is an organic additive used in the production of epoxy resins and polycarbonate plastics and because of this it is used in the internal coating of cans and in plastic bottle production. Depending on several factors, BPA can migrate from these materials to the soft drink and so, it can be ingested by consumers causing hormonal and reproductive disorders. To estimate the Polish population exposure to BPA, several soft drinks belonging to different brands were purchased from a supermarket in the city of Warsaw and analysed. The result of the analysis highlight that mean BPA exposure in the Polish population exceeds the tolerable daily intake proposed by the EFSA scientific opinion, raising health concerns. On the other hand, the second study, focused on cadmium exposure due to chocolate consumption by Polish population, did not raise any health concern. Cadmium is a heavy metal that naturally occurs in its inorganic form in the environment and its presence in chocolate derives only from the cocoa beans and not from contamination during processing. Its accumulation in the human body can create several adverse effects, including renal dysfunction and failure. To estimate the Polish population exposure to cadmium, several chocolate bars were purchased from a supermarket in the city of Warsaw and analysed. The results of the analysis show that cadmium exposure in the Polish population does not exceed the tolerable weekly intake proposed by the EFSA scientific opinion

A Novel MIMO Control for Interleaved Buck Converters in EV DC Fast Charging Applications

This brief proposes a new multiple input multiple output (MIMO) control for off-board electric vehicle (EV) dc fast chargers. The proposed feedback matrix design avoids multiple tuning of controllers in multiple and interconnected loops while improving the performance of interleaved dc buck converters over classical PI/PID controls. The innovative features of the presented strategy are the reference current monotonic tracking from any initial state of charge with an arbitrarily fast settling time and the fast compensation of both load variations and imbalances among the legs. Numerical results validate the performance improvements of the proposed discrete-time MIMO algorithm for interleaved buck converters over classical PI/PID controls. Full-scale hardware-in-the-loop (HIL) and scaled-down prototype experimental results prove the feasibility and effectiveness of the proposal

Dual-Active-Bridge Model and Control for Supporting Fast Synthetic Inertial Action

This article proposes a dual-active-bridge control to support the fast synthetic inertial action in DC microgrids. First of all, the selection of the isolated DC/DC converter to link an energy storage system with the DC bus in a microgrid is analyzed and the advantages of the dual-active-bridge converter controlled by a single-phase shift modulation justify its selection. An active front-end can be then adapted to connect the DC bus with an AC grid. Secondly, this paper presents the design of a discrete PI controller for supporting fast synthetic inertial action. In particular, a discrete dual-active-bridge model based on the transferred power between both converter bridges, which overcomes the approximations of the output current linearization model, is proposed. Moreover, the article introduces a novel equation set to directly and dynamically tune discrete PI parameters to fulfill the design frequency specifications based on the inversion formulae method. In this way, during the voltage/power transients on the DC bus, the controller actively responds and recovers those transients within a grid fundamental cycle. Since the developed set of control equations is very simple, it can be easily implemented by a discrete control algorithm, avoiding the use of offline trial and error procedures which may lead to system instability under large load variations. Finally, the proposed control system is evaluated and validated in PLECS simulations and hardware-in-the-loop tests

The mosaic leafhopper Orientus ishidae: host plants, spatial distribution, infectivity, and transmission of 16SrV phytoplasmas to vines

Orientus ishidae (Matsumura) is an Asian species introduced into Europe and recently associated with 16SrV phytoplasmas, related to grapevine “flavescence dorée”. Its life cycle, host plants, spatial distribution, infection and vector capability have been investigated in vine-growing areas of Piedmont, NW Italy. The spatial distribution of adults in vineyards was studied by applying interpolation methods to trap capture data. Insects were subject to molecular analyses to verify phytoplasma presence and identity. DNA extraction and PCR were made to detect 16SrV phytoplasmas. Transmission experiments were set up, using different sources for phytoplasma acquisition, and two plant species and an artificial diet for inoculation. Whole mount in situ hybridization was made to detect phytoplasmas in the salivary glands of adults. In the vineyard agro-ecosystem, 19 plant species (11 families), mainly broadleaf trees and shrubs, were recognized as host plants of the insect. Adults were more abundant on putative host plants than on grapevines, with a clear clustering at the edges of vineyards, and without a massive intrusion into the vineyard from outside. 16SrV phytoplasmas were detected only in adults captured with yellow sticky traps (20 out of 188 tested). The transmission of 16SrV phytoplasmas was successful after phytoplasma acquisition from infected broad bean and inoculation on grapevine

Evaluation of the Antioxidant Capacity of Fruit Juices by Two Original Analytical Methods

Two analytical methods previously developed by our groups were employed to estimate the antioxidant capacity of commercial fruit juices. The electrochemical method, which measures the scavenging activity of antioxidants towards OH radicals generated by both hydrogen peroxide photolysis and Fenton’s reaction, is based on the recovery of the cyclic voltametric response of the redox probe Ru(NH3)63+ at a Glassy Carbon electrode modified with a thin film of an insulating polyphenol, in the presence of compounds with antioxidant properties. The values of the antioxidant capacity of the fruit juices are expressed as vitamin C equivalents/L. The chromatographic method is based on the generation of OH radicals via Fenton’s reaction in order to test the inhibition of their formation in the presence of antioxidant compounds by monitoring salicylate aromatic hydroxylation derivatives as markers of •OH production, by means of HPLC coupled to coulometric detection. The results are expressed as the percentage of inhibition of •OH production in the presence of the tested juice compared to the control sample. When OH radicals are produced by Fenton’s reaction, the antioxidant capacity of the juices, estimated by both methods, displays an analogous trend, confirming that they can be considered an alternative for measuring the ability of antioxidants to block OH radical formation

Changes in carotenoids, phenolic acids and antioxidant capacity in bread wheat doughs fermented with different lactic acid bacteria strains

Amongst the processing technologies able to improve the functional features of cereal-based foods, sourdough fermentation using Lactic Acid Bacteria (LAB) has been recently rediscovered for its beneficial effects. Wheat (Triticum aestivum L.) bread doughs were prepared using LAB strains belonging to different Lactobacillus species and changes in phenolic acid, carotenoid content and antioxidant capacity were evaluated. Two L. plantarum strains out of six were able to significantly increase carotenoid content in the dough, suggesting that a higher mobilization/solubilisation of these antioxidant compounds occurs. Within different fractions (free, soluble-conjugated, insoluble-bound), the relative distribution of ferulic acid and antioxidant activity changes depending on the specific strain. Overall, results indicate that some LAB strains cause in situ changes, significantly increasing the content of functional compounds in doughs during fermentation. This, in turn, could improve the functional features of bakery foods characterised by a high content in carotenoids and other bioactive compounds