Photocatalyst TiO2–Co: the effect of doping depth profile on methylene blue degradation

In this work, we study the effect of doping depth profile on the photocatalytic and surface properties of TiO₂ films. Two thin film layers of TiO₂ (200 nm) and Co (5 nm), respectively, were deposited by physical evaporation on glass substrate. These films were annealed for 1 s at 100 and 400 °C and the Co layer was removed by chemical etching. Atomic force microscopy (AFM) phase images showed changes in the surface in function of thermal treatment. The grazing-incidence X-ray fluorescence (GIXRF) measurements indicated that the thermal treatment caused migration of Co atoms to below the surface, the depths found were between 19 and 29 nm. The contact angle showed distinct values in function of the doped profile or Co surface concentration. The UV–vis spectra presented a red shift with the increasing of thermal treatment. Photocatalytical assays were performed by methylene blue discoloration and the higher activity was found for TiO₂–Co treated at 400 °C, the ESI-MS showed the fragments formed during the methylene blue decomposition.     

Use of the jabuticaba (Myrciaria cauliflora) depulping residue to produce a natural pigment powder with functional properties

The aim of this study was to produce a natural pigment powder with functional properties. To optimise the spray-drying process, a central composite design with 17 treatments was used, in which the independent variables were the inlet drying air temperature (138–202 °C), the feed flow rate (20–67 mL/min), and the concentration of the carrier (maltodextrin, 100–300 g/kg of extract). The dependent variables were the moisture content, hygroscopicity, and anthocyanin retention. The samples were analysed by: anthocyanin and phenolic content; antioxidant properties based on the ORAC and DPPH assays; antimicrobial activity against Staphylococcus aureus, Listeria monocytogenes, Salmonella enteritidis, and Escherichia coli; and inhibitory activity against arginase, an enzyme produced by Leishmania amazonensis. The experimental design was not significant or predictive in the ranges studied. The selected samples contained high concentrations of anthocyanins and phenolics, and high antioxidant capacities. In addition, they exhibited antimicrobial activity against three of the four microorganisms tested, and some of the samples also exhibited a bactericidal effect. Moreover, the powders exerted inhibitory activity (64–69%) against arginase. The results obtained in this study suggest that the jabuticaba depulping residue could be used to produce a natural pigment with functional properties.     

Toxic metals (Hg, Cd, and Pb) in fishery products imported into Italy: suitability for human consumption

Mercury, cadmium, and lead concentrations were determined in various fishery products (fishes, cephalopod molluscs, and crustaceans) imported into Italy from many European and non-European coastal countries. Considerable differences were found in the concentrations of these metals among the products tested. The highest mean Hg concentration was found in fishes (0.21 μg g(-1) wet weight), whereas cephalopods had the highest mean Cd concentration (0.35 μg g(-1) wet weight). Swordfish (0.80 μg g(-1) wet weight), longtail tuna (0.53 μg g(-1) wet weight), and thornback ray (0.52 μg g(-1) wet weight) had the highest concentrations of Hg, whereas maximum Cd concentrations were found in samples of common cuttlefish (0.85 μg g(-1) wet weight) and common octopus (0.64 μg g(-1) wet weight). The majority of the samples analyzed were in compliance with European Union legislation, except for a few cases. The calculated mean weekly intakes of Hg, Cd, and Pb through consumption of the fishery products tested were all below the legislated respective provisional tolerable weekly intakes. In general, the samples analyzed were considered safe to eat with regard to the metal concentrations found and the allowable intakes based on legislation. Nevertheless, the consumption of some species may be of significant importance for consumer health.     

Synergism between lipoxygenase‐active soybean flour and ascorbic acid on rheological and sensory properties of wheat bread

BACKGROUND: The interaction between lipoxygenase‐active soybean flour (LOX) and ascorbic acid (AA), on colour, rheological and sensory properties of wheat bread was studied with the aim of reducing the applied quantity of additives in bread formulations. RESULTS: The ascorbic acid (0–500 ppm) and active soybean flour (0–1%) mixture improved bread‐crumb colour by lowering the yellow hue in a higher proportion than those expressed by the components alone, characterising a synergistic mechanism (?_b = 15.1? (1.7 × LOX) ? (0.5 × AA) ? (5.8 × LOX × AA), where ?_b represent the estimated value for the yellow hue parameter). No differences in flavour and porosity were seen between the samples. As supported by the instrumental methods, breads made with active soybean flour and ascorbic acid (LOX + AA) had whiter crumbs and were softer and springier than controls as assessed by a trained sensory panel. In summary, the combination of both active soybean flour and ascorbic acid showed synergism, promoting a greater bleaching effect than when used alone. CONCLUSION: These results suggest the potential use of active soybean flour as a synergistic ingredient in the substitution of artificial additives in bread making. Since the interaction on the bleaching response was not linear and active soybean flour showed a higher iron concentration (66.40 ± 4.23 µg g^?1) than non‐active soybean flour (52.30 ± 0.40 µg g^?1), more studies are warranted to establish the biochemical mechanisms involved in this interaction. Copyright © 2007 Society of Chemical Industry     

Stability of emulsions formulated with high concentrations of sodium caseinate and trehalose

Stability of emulsions formulated with 10 wt.% oil (concentrated fish oil, CFO, sunflower oil, SFO, or olive oil, OO), sodium caseinate concentrations varying from 0.5 to 5 wt.%, giving oil-to-protein ratios of 20–2, and 0, 20, 30 or 40 wt.% aqueous trehalose solution was studied by Turbiscan. Particle size distribution, microstructure, and small angle X-ray scattering (SAXS) patterns were also obtained. The main mechanism of destabilization in a given formulation strongly depended on oil-to-protein ratio. As evidenced by the BS-profile changes with time, emulsions formulated with 0.5 and 1 wt.% NaCas destabilized mainly by creaming while for the 2 wt.% NaCas concentration, both creaming and flocculation mechanisms, were involved. The main destabilization mechanism for the 3, 4 or 5 wt.% NaCas emulsions was flocculation. Stability of emulsions was also affected by the content of trehalose in the aqueous phase. Trehalose diminished the volume-weighted mean diameter (D_4,3) and greatly improved stability.     

Removal of pharmaceuticals in sewage treatment plants in Italy

A listing of "priority pharmaceuticals" for human use in Italy resulted in the selection of 26 pharmaceuticals, belonging to 11 therapeutic classes. They were analyzed by liquid chromatography-tandem mass spectrometry, their occurrence was assessed in six sewage treatment plants (STPs), and the loads and the removal rates (RR) were studied. Total loads ranged from 1.5 to 4.5 g/day/1000 inhabitants in influents and 1.0 and 3.0 g/day/1000 inhabitants in effluents. Total RR in STPs were mostly lower than 40%. Pharmaceuticals could be divided into three groups according to their behavior in STPs: one group with RR higher in summer than in winter, one group with RR similar in summer and winter, and a last group not removed. Last, we studied the distribution and fate of residual pharmaceuticals in the surface waters receiving the effluents of the STPs and identified degradation and sorption as the major factors affecting attenuation. Ciprofloxacin, ofloxacin, sulfamethoxazole (antibiotics), atenolol (cardiovascular drug), ibuprofen (antiinflammatory), furosemide, hydrochlorothiazide (diuretics), ranitidine (gastrointestinal drug), and bezafibrate (lipid regulator) were the most abundant residual drugs, thus those of environmental concern.     

Spray drying of a phenolic‐rich membrane filtration fraction of olive mill wastewater: optimisation and dried product quality

Olive mill wastewater (OMWW) from 3‐ and 2‐phase mills was subjected to a two‐step membrane filtration process. The obtained reverse osmosis retentate (RO‐R) is a phenolic‐rich coproduct stream, and the reverse osmosis permeate is a near‐pure water stream. A pilot‐scale spray dryer was used for the production of RO‐R powder. The optimum temperature/feed pump conditions were obtained for 3‐phase (150°C/4.4 Hz) and for 2‐phase RO‐R (175°C/3.8 Hz). The powders obtained by spray drying under these conditions were analysed for physicochemical properties, including identification and quantification of phenolic compounds. Protocatechuic acid, 3‐hydroxytyrosol, tyrosol, vanillic acid and p‐coumaric acid were quantified in both RO‐R powders, which show the possibility to obtain a phenolic‐rich powder from an OMWW filtration fraction. This will lead towards better usage of by‐products from olive oil production.