Surprisingly high fluorine content in some exotic superfoods

Plasma sprayed fluoride and zinc doped hydroxyapatite coated titanium for load-bearing implants

Titanium (Ti) alloys show excellent fatigue and corrosion resistance, high strength to weight ratio, and no toxicity; however, poor osseointegration ability of Ti may lead to implant loosening in vivo. Plasma spraying of hydroxyapatite [HA, Ca₁₀ (PO₄)₆ (OH)₂] coating on Ti surfaces is commercially used to enhance osseointegration and the long-term stability of these implants. The biological properties of HA can be improved with the addition of both cationic and anionic dopants, such as zinc ions (Zn²⁺) and fluoride (F^-). However, the hygroscopic nature of fluoride restricts its utilization in the radiofrequency (RF) plasma spray process. In addition, the amount of doping needs to be optimized to ensure cytocompatibility. We have fabricated zinc and fluoride doped HA-coated Ti6Al4V (Ti64) to mitigate these challenges using compositional and parametric optimizations. The RF induction plasma spraying method is utilized to prepare the coatings. Multiple parametric optimizations with amplitude and frequency during the processing result in coating thicknesses between 80 and 145 μm. No adverse effects on the adhesion properties of the coating are noticed because of doping. The antibacterial efficacy of each composition is tested against S. aureus for 24, 48, and 72 h, and showed that the addition of zinc oxide and calcium fluoride to HA leads to nearly 70 % higher antibacterial efficacy than pure HA-coated samples. The addition of osteogenic Zn²⁺and F^- leads to 1.5 times higher osteoblast viability for the doped samples than pure HA-coated samples after 7-days of cell culture. Zn²⁺ and F^- doped HA-coated Ti64 with simultaneous improvements in anti-bacterial efficacy and in vitro biocompatibility can find application in load-bearing implants, particularly in revision surgeries and immune-compromised patients.

Fluoride Content of Matcha Tea Depending on Leaf Harvest Time and Brewing Conditions

Matcha, or powdered green tea (Camellia sinensis) of the Tencha type, is popular all around the world, and its consumption continues to rise. Because of its unique cultivation method, it is rich in phytochemicals and has many health-promoting properties; it contains high concentrations of polyphenols, theanine and chlorophyll. Tea, and by extension matcha, contains numerous minerals, one of which is fluorine. Under physiological conditions, this mineral plays a significant role in hard tissue mineralisation processes. However, even in low concentrations, with prolonged exposure, fluoride can accumulate in the body, leading to a number of harmful effects. The aim of this study was to evaluate, for the first time, the fluoride content of the matcha infusions from different harvests, brewed using water at different temperatures (25 °C, 70 °C, 80 °C and 90 °C). The content of fluoride ions was measured by the potentiometric method. The fluoride content ranged from 3.36 to 4.03 mg/L and was dependent on both the leaf harvest time and brewing temperature. The concentration of this mineral in the dry powder ranged from 118.39 to 121.65 mg/kg. Irrespective of the water temperature or harvest time, matcha was found to have a high fluoride content, with particularly high concentrations being noted in the powder itself.

The Public’s Understanding of Superfoods

The term “superfood” is linked to food that is beneficial to health. However, there is no legal or clear scientific definition, and little is known about individual perceptions of this food group. Therefore, an online survey was conducted (n = 1006 respondents) to assess the public’s understanding of superfoods in Germany, including (a) the conceptual understanding of the term “superfood”, (b) corresponding consumption behavior, and (c) the risk–benefit appraisal. In total, 70% of respondents were aware of the term “superfood”, and 33% reported consuming superfoods at least once a week. The term was mainly associated with positive food properties, such as “healthy” and “contains vitamins”. Health benefits were rated to be much higher than potential health risks. In addition, imported foods were more likely to be labelled as superfoods, compared to domestic equivalents. In further analyses, we found women, younger people, and organic buyers to have an even more positive impression. That is, specific parts of the population may be particularly attracted to superfood products. Therefore, target-group specific information campaigns can be a useful tool to increase the population’s awareness of the potential health risks of superfood consumption and to highlight the presence of equivalent “domestic superfoods” in Germany.

Chemical Aspects of Human and Environmental Overload with Fluorine

Over the last 100-120 years, due to the ever-increasing importance of fluorine-containing compounds in modern technology and daily life, the explosive development of the fluorochemical industry led to an enormous increase of emission of fluoride ions into the biosphere. This made it more and more important to understand the biological activities, metabolism, degradation, and possible environmental hazards of such substances. This comprehensive and critical review focuses on the effects of fluoride ions and organofluorine compounds (mainly pharmaceuticals and agrochemicals) on human health and the environment. To give a better overview, various connected topics are also discussed: reasons and trends of the advance of fluorine-containing pharmaceuticals and agrochemicals, metabolism of fluorinated drugs, withdrawn fluorinated drugs, natural sources of organic and inorganic fluorine compounds in the environment (including the biosphere), sources of fluoride intake, and finally biomarkers of fluoride exposure.

Development of the New Fluoride Ion-Selective Electrode Modified with FexOy Nanoparticles

A new modified ion-selective electrode with membranes of LaF₃ single crystals with different internal contacts (solid steel or electrolyte) and with Fe_xO_y nanoparticles as loading was developed. The best response characteristic with linear potential change was found in the fluoride concentration range from 10⁻¹ to 3.98 × 10⁻⁷ M. The detection limit for the electrolyte contact was determined at 7.41 × 10⁻⁸ M with a regression coefficient of 0.9932, while the regression coefficient for the solid contact was 0.9969. The potential change per concentration decade ranged from 50.3 to 62.4 mV, depending on whether the contact was solid or electrolytic. The prepared modified electrode has a long lifetime, as well as the possibility of application in different positions (solid contact), and it can also be used for the determination of iron ions. The electrode characterization was performed with scanning electron microscopy and elemental analysis with the technique of electron-dispersive X-ray spectroscopy.