Rapid and easy ICP OES determination of selected major, minor and trace elements in Pu-erh tea infusions using the response surface methodology along with the joint desirability function approach.

A new analytical method was proposed for multielement (Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Sr and Zn) analysis of Pu-erh teas infusions by inductively coupled plasma optical emission spectrometry. The Box-Behnken response surface design together with individual desirability functions and the joint desirability function approach was applied to develop experimental conditions of this new procedure, being alternative to high-temperature wet digestion. The procedure involved the samples to be just 5-fold diluted with 1.7 mol L-1 HNO3. The proposed method was precise (relative standard deviations within 2-8%), true (relative errors from -8 to +6%) and guaranteed very good detectability (detection limits within 1-6 ng g-1, except for Ca and Fe). It was used for analysis of infusions of Pu-erh teas as well as to verify the effect of their preparation conditions (steeping water temperature, steeping time).

Response surface methodology assisted development of a simplified sample preparation procedure for the multielement (Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Sr and Zn) analysis of different coffee brews by means of inductively coupled plasma optical emission spectrometry.

The Box-Behnken response surface design together with the individual desirability functions were used to develop the new and greenish sample preparation procedure of coffee brews prior to their multielement (Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Sr and Zn) analysis by inductively coupled plasma optical emission spectrometry (ICP OES). The developed procedure required only 2-fold dilution of the samples with a 1.8 mol L-1 HNO3 solution and then, the sonication of the resulting samples solutions for 8 min at room temperature. The proposed method was precise (0.6-7.5% as RSD), true (relative errors changing from -5.2% to +4.6%) and guaranteed the limits of detection (LODs) of the studied elements between 0.1 and 5 ng g-1. Finally, this simplified ICP OES based method was applied for the multielement analysis of brews of different Arabica coffees as well as those prepared with seldomly reported devices, i.e., dripper, slow dripper, French press, aeropress and syphon.

Application of cold atmospheric pressure plasmas for high-throughput production of safe-to-consume beetroot juice with improved nutritional quality.

A one-step, highly-efficiency, and low-cost cold atmospheric pressure plasma (CAPP)-based method for obtaining safe-to-consume beetroot juice (BRJ) with enhanced nutritional quality is presented. Three reaction-discharge systems with different CAPPs were studied to check how the composition and physicochemical properties changed during CAPP treatment of BRJ. To identify reactive species occur in gas phase of applied CAPP for BRJ treatment, optical emission spectrometry was used. Finally, the cytotoxicity of so-obtained BRJ to human epithelial colorectal adenocarcinoma (Caco-2) and human non-malignant intestine microvascular endothelial cells (HIMEC) was assessed. Based on the performed analyses it was found that controlled CAPP treatment of BRJ changes the fraction pattern of elements in addition to increase the content of phenolic compound presents in BRJ. Furthermore, the defined CAPP treatment of BRJ inhibits proliferation of Caco-2 cell lines, exhibiting non-cytotoxic effect for HIMEC non-malignant endothelial cells. As a result, safe-to-consume BRJ of improved nutritional quality was produced.

Plant Extracts Activated by Cold Atmospheric Pressure Plasmas as Suitable Tools for Synthesis of Gold Nanostructures with Catalytic Uses.

Because cold atmospheric pressure plasma (CAPP)-based technologies are very useful tools in nanomaterials synthesis, in this work we have connected two unique in their classes approaches-a CAPP-based protocol and a green synthesis method in order to obtain stable-in-time gold nanoparticles (AuNPs). To do so, we have used an aqueous Gingko biloba leave extract and an aqueous Panax ginseng root extract (untreated or treated by CAPP) to produce AuNPs, suitable for catalytical uses. Firstly, we have adjusted the optical properties of resulted AuNPs, applying UV/Vis absorption spectrophotometry (UV/Vis). To reveal the morphology of Au nanostructures, transmission electron microscopy (TEM) in addition to energy dispersive X-ray scattering (EDX) and selected area X-ray diffraction (SAED) was utilized. Moreover, optical emission spectrometry (OES) in addition to a colorimetric method was used to identify and determine the concentration of selected RONS occurring at the liquid-CAPP interface. Additionally, attenuated total reflectance Fourier transform-infrared spectroscopy (ATR FT-IR) was applied to reveal the active compounds, which might be responsible for the AuNPs surface functionalization and stabilization. Within the performed research it was found that the smallest in size AuNPs were synthesized using the aqueous P. ginseng root extract, which was activated by direct current atmospheric pressure glow discharge (dc-APGD), generated in contact with a flowing liquid cathode (FLC). On the contrary, taking into account the aqueous G. biloba leave extract, the smallest in size AuNPs were synthesized when the untreated by CAPP aqueous G. biloba leave extract was involved in the Au nanostructures synthesis. For catalytical studies we have chosen AuNPs produced using the aqueous P. ginseng root extract activated by FLC-dc-APGD as well as AuNPs synthesized using the aqueous G. biloba leave extract also activated by FLC-dc-APGD. Those NPs were successfully used as homogenous catalysts for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP).

Room temperature solvent extraction for simple and fast determination of total concentration of Ca, Cu, Fe, Mg, Mn, and Zn in bee pollen by FAAS along with assessment of the bioaccessible fraction of these elements using in vitro gastrointestinal digestion.

BACKGROUND AND AIM: Bee pollen is recognized to be a source of different nutrients, including minerals. As a food supplement, its quality and safety due to concentrations of essential macro- and microelements, and harmful trace elements has to be verified. Fast and simple element analysis of bee-collected pollen can be regarded as an important part of its quality assurance and control. The present study aimed at developping a new method for determination of selected elements (Ca, Cu, Fe, Mg, Mn, Zn) of bee pollen based on solvent extraction and completely avoiding a high temperature treatment with concentrated reagents. In addition, in vitro gastrointestinal digestion was used to assess bioavailability of elements from this food supplement. METHODS: Bee pollen samples were dried and pulverized. Total concentrations of Ca, Cu, Fe, Mg, Mn, and Zn were determined by flame atomic absorption spectrometry (FAAS) in sample solutions obtained by wet digestion (WD) in concentrated HNO3 or alternatively by solvent extraction (SE) with diluted solutions of HNO3. Gastrointestinal digestion was mimicked using simulated solutions of gastric and intestinal juices followed by determination of Ca, Cu, Fe, Mg, Mn and Zn concentrations in the bioaccessible fraction by FAAS. RESULTS: A new simple and fast method for determination of total concentrations of Ca, Cu, Fe, Mg, Mn, and Zn in bee pollen was developed and validated. The method combined room temperature, two-hour SE with 0.5 mol L-1 HNO3 with FAAS measurements versus simple standard solutions. It provided precision within 1-5 % and trueness better than 8%, and was shown to be suitable for fast analysis of different polyfloral bee pollens. In vitro gastrointestinal digestion revealed that elements were well (70-85 % for Ca, Mg) and fairly (27-43 % for Cu, Fe, Mn, and Zn) bioaccessible from bee pollen. By pouring with water and swelling overnight, bioaccessibility of studied elements from such prepared bee pollen was increased on average by less than 15 % (Mn), 20 % (Ca, Cu, Fe, Zn) or 30 % (Mn). CONCLUSIONS: Avoiding long-lasting, high-temperature wet digestion with concentrated reagents, the proposed sample treatment along with FAAS provided precise and true results of total concentrations of Ca, Cu, Fe, Mg, Mn, and Zn in bee pollen. The method was simple and fast, and enabled to analyze a higher number of samples. Simulated gastrointestinal digestion of bee pollen have shown for the first time that Ca and Mg are the most bioaccessible from this bee product. Bioaccessibility of Cu, Fe, Mg, and Zn from bee pollen are close to or lower than 40 %.

The determination of elements in herbal teas and medicinal plant formulations and their tisanes.

Elemental analysis of herbal teas and their tisanes is aimed at assessing their quality and safety in reference to specific food safety regulations and evaluating their nutritional value. This survey is dedicated to atomic spectroscopy and mass spectrometry element detection methods and sample preparation procedures used in elemental analysis of herbal teas and medicinal plant formulations. Referring to original works from the last 15 years, particular attention has been paid to tisane preparation, sample matrix decomposition, calibration and quality assurance of results in elemental analysis of herbal teas by different atomic and mass spectrometry methods. In addition, possible sources of elements in herbal teas and medicinal plant formulations have been discussed.