Challenges and potential for detecting and quantifying titanium dioxide in food.

BACKGROUND: Titanium dioxide (TiO2) is banned in some countries but its use is still permitted in others. The global food supply chain is therefore challenged with the need to use rapid and reliable testing methods to either detect the presence of TiO2 or to quantify its concentration. The goal of this study was to determine the feasibility of using color, texture profile analysis, Raman microscopy, and X-ray fluorescence (XRF) spectroscopy to detect and quantify TiO2 in fillings used in the pastry and confectionery industry. In this study, two types of fillings were investigated: vanilla based and chocolate based. All fillings were prepared in four different variations - without TiO2 and with three concentrations as follows: 0.25 g*kg-1, 0.5 g*kg-1, or 0.75 g*kg-1 TiO2 per sample. The methods were selected for their ability to analyze the samples in a short period of time. RESULTS: All of the methods showed moderate to high potential for detecting TiO2 in the samples. The results reveal how TiO2 affects the food matrix color and texture. Use of Raman microscopy confirms its detectability, although concentrations of TiO2 do not follow a pattern. X-ray fluorescence spectroscopy showed the greatest potential as it can not only detect TiO2 but can also quantify its concentration in the samples. CONCLUSIONS: The highest potential for quantifying the concentration of this food additive was achieved with XRF. © 2024 Society of Chemical Industry.

Irregular influence of alkali metals on Cu-SAPO-34 catalyst for selective catalytic reduction of NOx with ammonia.

SCR activity of Cu-SAPO-34 catalyst was reduced by alkali metal ions. The alkali metals ions (Li+, Na+ and K+) have shown irregular influences on Cu-SAPO-34. The order of poisoning strengths under 400 °C was found to be: Na+ > K+ > Li+, which is not consistent with the basicities of their corresponding metals. Experimental results and calculations showed that the alkali metal ions readily replace H+ and Cu2+/Cu+ ions. These exchanges result in the loss of Brønsted acid sites and migration of isolated Cu2+ ions in Cu-SAPO-34, which decrease the NH3-SCR activity. Both the basicity and ion diameter will affect the exchanging behavior of an alkali ion. Na+ and Li+ ions will influence both H+ and Cu2+/Cu+ ions but K+ ions only preferably replace the H+. We hypothesize that K+ cannot enter into a small ring (6-membered ring) to replace a Cu2+/Cu+ ion because of its large ion diameter. The displaced Cu2+/Cu+ ions will transfer to adjacent unbonded Al site to form a CuAlO2 species.

Promoting effects of water on the NH3-SCR reaction over Cu-SAPO-34 catalysts: transient and permanent influences on Cu species.

Cu-SAPO-34 catalysts with varied Cu loadings were synthesized through ion exchange to study the influence of water on the NH3-SCR reaction. The catalytic activities were evaluated by selective catalytic reduction of NO under a reactant feed in the presence/absence of water. Transient experiments were designed to study the response of NO conversion to the presence of water. H2-TPR and DFT calculations were performed to study the reducibility of Cu species. NH3-TPD and XPS were conducted to reveal the migration of Cu species. The results show that water could remarkably improve NO reduction activities and the promoting effect is more significant on the catalyst with low Cu loading. Both transient and permanent influences were found in this promoting phenomenon. For the transient influence, water has been proved to accelerate the re-oxidation half-cycle. Moreover, water can enhance the promoting effect of the SCR feed on the migration of Cu species. These unanchored Cu ions migrate to defect sites to form active sites, which lead to a permanent influence of water.

Characterisation of peppermint (Mentha piperita L.) essential oil encapsulates.

Aim: The aim was to choose the optimal encapsulation system and to incorporate encapsulates loaded with essential oil into the ice cream as a model food product. Methods: Ca-alginate beads were produced by electrostatic extrusion process. Gelatine/alginate coacervates were processed with coacervation. Carnauba wax microparticles were produced using melt dispersion process. Morphological properties, chemical, and thermal stabilities of encapsulates were tested by SEM, FTIR spectral, and thermogravimetric analysis. Results: Alginate provided sufficient emulsion stability over 1 h. Ca-alginate showed higher encapsulation efficiency (EE) (98.4 ± 4.3%) compared to carnauba wax (94.2 ± 7.8%) and gelatine/alginate coacervates (13.2 ± 1.2%). The presence of essential oil in all three types of encapsulates confirmed with FTIR. The encapsulation process ensured controlled release and thermal stability of the oil. Conclusions: Ca-alginate matrix as the most suitable for peppermint essential oil encapsulation. The sensory analysis showed that ice cream incorporating encapsulates is a promising system for the consumption of health beneficial peppermint essential oil.

Novel modified nanocellulose applicable as reinforcement in high-performance nanocomposites.

The influence of modification and vacuum/supercritical CO2 (scCO2) drying methods on the surface properties, morphology and thermal stability of cellulose nanocrystals (NC) was presented in this study. Introduction of reactive vinyl groups on NC surface was performed by either direct esterification with oleic acid, linseed or sunflower oil fatty acids; or by amidation of maleic acid/ethylene diamine with methyl ester of fatty acid. Obtained modified NC (m-NC) were characterized using FTIR and Raman spectroscopy; and by determination of acid, iodine and ester values. Structural analysis of m-NC showed varieties of forms, from spongy to nanostructural non-uniform layered morphology with observable agglomeration, which confirmed morphology dependence on modification/processing methods Thermogravimetry-MS spectrometry showed different thermal stability and degradation pathways of NC/m-NC. Incorporation of 1 wt% of reactive m-NC in unsaturated polyester lead to high performance nanocomposites and contributed to increase of stress at break in the range from 76 to 93%.

Using the Literature to Understand Achilles' Fate.

According to Greek mythology, Achilles was fatally wounded in his heel, bled out, and died. Several unproven hypotheses mention poisoning, infection, allergy, hemophilia, thyrotoxic storm (ie, pain and stress), and suicide. The author, a plastic surgeon who often treats chronic wounds, proposes an additional scenario: Although not mortally wounded, Achilles was considered dead, because in his time a wounded hero was as good as a dead hero, so he lived out the remainder of his life as former hero with a chronic wound far away from everyone. To determine whether his injury was enough to cause fatal bleeding and quick death or if other factors might have been in play, a search of the literature was conducted to enhance what is known about Achilles, basically through the tale related in The Iliad and the clinical impact of an Achilles' injury. Search terms utilized included bleeding tibialis posterior artery (3 manuscripts were found) and chronic wound, Achilles tendon (631 manuscripts were located). Although science may not be able to explain how and why Achilles died, the literature supported the conjecture that Achilles probably had a chronic wound with skin and paratenon defect, de- vitalized tendon tissue, bleeding, granulation, and repeated infections. It is interesting to consider the state of his injury and his mind in the making of this legend.

Calcium-Alginate-Inulin Microbeads as Carriers for Aqueous Carqueja Extract.

Carqueja (Pterospartum tridentatum) is an endemic species and various bioactive compounds have been identified in its aqueous extract. The aim of this study was to protect the natural antioxidants from the aqueous extract of carqueja by encapsulation in Ca-alginate microbeads and Ca-alginate microbeads containing 10% and 20% (w/v) of inulin. The microbeads produced by electrostatic extrusion technique had an average diameter from 625 µm to 830 µm depending on the portion of inulin. The sphericity factor of the hydrogel microbeads had values between 0.014 and 0.026, while freeze dried microbeads had irregular shape, especially those with no excipient. The reduction in microbeads size after freeze drying process (expressed as shrinkage factor) ranged from 0.338 (alginate microbeads with 20% (w/v) of inulin) to 0.523 (plain alginate microbeads). The expressed radical scavenging activity against ABTS and DPPH radicals was found to be between 30% and 40% for encapsulated extract, while the fresh extract showed around 47% and 57% of radical scavenging activity for ABTS and DPPH radicals, respectively. The correlation between antioxidant activity and the total phenolic content were found to be positive (in both assay methods, DPPH and ABTS), which indicate that the addition of inulin didn't have influence on antioxidant activity. The presence of inulin reduced stiffness of the hydrogel, and protected bead structure from collapse upon freeze-drying. Alginate-inulin beads are envisaged to be used for delivery of aqueous P. tridentatum extract in functional food products.

The adsorption of pharmaceutically active compounds from aqueous solutions onto activated carbons.

In this study, the adsorption of pharmaceutically active compounds - salicylic acid, acetylsalicylic acid, atenolol and diclofenac-Na onto activated carbons has been studied. Three different commercial activated carbons, possessing ∼650, 900 or 1500m(2)g(-1) surface areas were used as solid adsorbents. These materials were fully characterized - their textural, surface features and points of zero charge have been determined. The adsorption was studied from aqueous solutions at 303K using batch adsorption experiments and titration microcalorimetry, which was employed in order to obtain the heats evolved as a result of adsorption. The maximal adsorption capacities of investigated solids for all target pharmaceuticals are in the range of 10(-4)molg(-1). The obtained maximal retention capacities are correlated with the textural properties of applied activated carbon. The roles of acid/base features of activated carbons and of molecular structures of adsorbate molecules have been discussed. The obtained results enabled to estimate the possibility to use the activated carbons in the removal of pharmaceuticals by adsorption.

The effect of substituents on the surface modification of anatase nanoparticles with catecholate-type ligands: a combined DFT and experimental study.

The surface modification of nanocrystalline TiO2 particles (45 Å) with catecholate-type ligands having different electron donating/electron withdrawing substituent groups, specifically 3-methylcatechol, 4-methylcatechol, 3-methoxycatechol, 3,4-dihydroxybenzaldehyde and 4-nitrocatechol, was found to alter the optical properties of nanoparticles in a similar way to catechol. The formation of the inner-sphere charge-transfer (CT) complexes results in a red shift of the semiconductor absorption compared to unmodified nanocrystallites and a reduction of the effective band gap, being slightly less pronounced in the case of electron withdrawing substituents. The investigated ligands have the optimal geometry for binding to surface Ti atoms, resulting in ring coordination complexes of the catecholate type (binuclear bidentate binding-bridging) thus restoring six-coordinated octahedral geometry of surface Ti atoms. From the absorption measurements (Benesi-Hildebrand plot), the stability constants in methanol/water = 90/10 solutions at pH 2 in the order of 10(3) M(-1) have been determined. The binding structures were investigated by using FTIR spectroscopy. Thermal stability of CT-complexes was investigated by using TG/DSC/MS analysis. Quantum chemical calculations on model systems using density functional theory (DFT) were performed to obtain the vibrational frequencies of charge transfer complexes, and the calculated values were compared with the experimental data.

Clinical and pathological features of the giant, invasive basal cell carcinoma of the scalp.

BACKGROUND: The giant, invasive basal cell carcinoma of the scalp is a rare clinical form of this tumor that appears on the skin, but may spread to some of the following structures: soft tissues of the scalp, bones, meninges, and the brain. In literature, so far, it is known as the GBCC. It is caused by aggressive BCC subtypes. METHODS: We will present here a research of clinical and pathological features of 47 pathological specimens in 31 patients where the following features were examined: the dimension of the tumor, the dimension of the tissue segment, tumor area, segmentation area, resection margin width, microscopic resection margin status, tumor invasion level, and the outcome. RESULTS AND CONCLUSIONS: We have concluded that microscopic resection margin dimensions from 1 to 10 mm are safe and that relapse occurrences in giant, invasive BCCs of the scalp depend on microscopic resection margin dimensions, resection margin status, tumor invasion levels, risky occupation, and risky behavior of the patient.

[Clinical-epidemiologic characteristics of large, invasive basal cell carcinomas of the scalp].

We studied a large, invasive basal cell carcinoma of the scalp in 42 operated patients (53 tumors) of which 26 patients with recurrent and 16 with no recurrence. This is a rare clinical form of this tumor that invades the skin in addition to some or all of the following structure: soft tissue scalp, skull, brain and brain membranes. The literature is known as the Giant basal cell carcinoma according to TNM classification of BCC in pT4 stage. Caused by aggressive subtypes of BCC. Treatment is surgical and involves only large, mutilate surgery and extensive reconstruction. Relapse often occurs. The aim was to analyze clinical and epidemiological characteristics of large, invasive basal cell carcinoma of the scalp, finding the causes of relapse and proposal timely diagnosis. We have concluded that the appearance of tumors in the frontal and pariental region of the scalp is related to the presence of known risk factors, that tumors often penetrate bones and brains resulting in more frequent recurrence in this localization. All tumors were caused by aggressive forms of BCC. Patients in the group with recurrent, previously responded to treatment and had more surgery than patients without recurrence. Treatment-related adverse events occurred in most patients (recurrence and/or death).

Unusual localisation of pressure ulcer--the vulva.

Only a few papers have been published about unusual localisations of pressure ulcer. To date, no papers were published presenting pressure ulcer on external genitals in women. The paper presents the mechanism of origin of vulval pressure ulcer, surgical treatment (excision of lesion tissue of the pressure ulcer) and reconstruction of the vulva. The patient, aged 50, has been paraplegic for 20 years. During the last 3 years she has had a wound which was spreading in the region of the vulva. The pressure ulcer was surgically removed, external female genitals were reconstructed using advancement skin flap and the function and natural appearance of organs were re-established. The presence of all three aetiological factors for the formation of pressure ulcer - presence of prolonged pressure, swelling and infection - were proven in the described patient. For this reason, we are able to claim that this was in fact a pressure ulcer of the vulva. Reconstruction was simple without any complications and donor-site morbidity.

The investigation of phenol removal from aqueous solutions by zeolites as solid adsorbents.

This work reports results on phenol adsorption from aqueous solutions on synthetic BEA (ß) and MFI (ZSM-5) zeolites, studied by heat-flow microcalorimetry. For the sake of comparison, the adsorption was performed on activated carbon, a solid customarily used for removal of phenol from water. The obtained values of heats evolved during phenol adsorption indicate the heterogeneity of active sites present on the investigated systems for the adsorption of phenol. In addition, the amounts of adsorbed pollutant were determined and presented in the form of adsorption isotherms, which were interpreted using Langmuir, Freundlich, Dubinin-Astakov and Sips' equations. The latter was found to express high level of agreement with experimental data. The results obtained in this work reveal that the adsorption of phenol on zeolites depends on both Si/Al ratio and on the pore size. Hydrophobic zeolites that possess higher contents of Si show higher affinities for phenol adsorption. Among investigated zeolites, zeolite ß possesses the highest capacity for adsorption of phenol. The possibility of regeneration of used adsorbents was investigated by thermal desorption technique. It has been shown that in the case of ß zeolite the majority of adsorbed phenol is easily released in the low temperature region.

The adsorption of nicotine from aqueous solutions on different zeolite structures.

The present work is focused on the adsorption of nicotine from aqueous solutions. Based on the data available in the literature, serious concern is claimed regarding the appearance of nicotine in ground, surface and municipal wastewaters. In order to investigate the possibility of abatement by adsorption, three different types of zeolites (BEA, MFI and HEU) have been applied as adsorbents. In addition, the adsorption was performed on activated carbon, a solid customarily used for removal of pollutants from water. The adsorption of nicotine was studied by isothermal microcalorimetry, which provided the heats evolved as a result of adsorption. The values of these heats revealed that the investigated solids are energetically heterogeneous for the adsorption of nicotine from aqueous solution. Additionally, the amounts of adsorbed pollutant were determined and presented in the form of adsorption isotherms. The obtained adsorption isotherms were interpreted using Langmuir, Freundlich, and Sips equations; the latter was found to express high level of agreement with experimental data of nicotine adsorption on the investigated solids. The possibilities to regenerate the adsorbents were examined by means of thermogravimetry coupled with mass spectrometry. From all obtained results, it was possible to distinguish zeolite BEA as a material which possesses the capacity for adsorption of nicotine comparable to that of activated carbon.