Adsorption of heavy metals by pirymidine-derivated mesoporous hybrid material

This paper describes the synthesis of pyrimidine-derivated hybrid mesoporous material via chemical bonding. This has been done by modifying the silanol groups of the support with a synthesised pyrimidine propyl triethoxysilane. The hybrid material has been characterized by X-ray diffraction, nitrogen adsorption techniques, FT-IR, ²⁹Si and ¹³C MAS NMR. The potential of the material of removing heavy metal as copper, nickel and cobalt from water has been tested. Effects of pH, velocity of adsorption, selectivity, maximum adsorption capacity and preconcentration capacity have been determined.     

A PCR assay to detect trace amounts of soybean in meat sausages

Soybean proteins are the most widely used source vegetable proteins in the meat industry because of several interesting characteristics. As soybean is included in the group of ingredients potentially allergenic, if not declared, it can be considered a hidden allergen, representing a potential risk to sensitised individuals. The aim of this work was to optimise and apply DNA‐based techniques for soybean detection in meat products, as alternative to the currently used protein‐based methods. The optimised polymerase chain reaction (PCR) protocol targeting the soybean lectin gene enabled the detection of the addition of 0.1% and 0.5% of hydrated textured protein, which corresponded to 0.01% and 0.06% (w/w) of soybean protein in unprocessed and heat‐processed pork meats, respectively. The established PCR technique, when applied to commercial meat sausages (eighteen samples), confirmed the presence of soybean declared in nine samples and indicated the presence of soybean in four samples with no labelled information about soybean. Additionally, the event‐specific PCR detection of Roundup Ready^® soybean was also performed, enabling the detection of transgenic DNA in three samples.     

Mixture Design Applied to Optimize a Directly Compressible Powder Produced via Cospray Drying

Coprocessing via spray drying was applied to improve the compactability of acetaminophen and to select an optimal formulation. Four-component mixtures containing acetaminophen, mannitol, erythritol, and maltodextrin were produced by cospray drying. A D-optimal mixture design was constructed to evaluate the spray dried powder and tablet properties. An increasing mannitol and erythritol content improved powder flowability and density. However, a higher erythritol concentration in the spray dried powder mixture had a negative influence on tablet tensile strength and friability. A higher maltodextrin content increased tablet tensile strength and improved tablet friability, while disintegration time, average particle size, powder flowability, density, and hygroscopicity were negatively influenced.     

Hoops: 3D Curves as Conservative Occluders for Cell-Visibility

Most visibility culling algorithms require convexity of occluders. Occluder synthesis algorithms attempt to construct large convex occluders inside bulky non-convex sets. Occluder fusion algorithms generate convex occluders that are contained in the umbra cast by a group of objects given an area light. In this paper we prove that convexity requirements can be shifted from the occluders to their umbra with no loss of efficiency, and use this property to show how some special non-planar, non-convex closed polylines that we call "hoops" can be used to compute occlusion efficiently for objects that have no large interior convex sets and were thus rejected by previous approaches.     

A potentiometric electronic tongue for the discrimination of honey according to the botanical origin. Comparison with traditional methodologies: Physicochemical parameters and volatile profile

The effectiveness of a potentiometric electronic tongue, made of various metals and metallic compounds was evaluated for the differentiation of honey in three different states: raw, liquefied and pasteurized. Principal component analysis (PCA) and a neural network showed that potentiometric electrodes seem useful to classify honey by its botanical origin, though they do not seem capable of discrimination between applied thermal treatments. The same was observed in the samples for physicochemical parameters and volatile compounds analysed with PCA. Au, Cu and Ag electrodes were more decisive in the discrimination of honey. A remarkable correlation (PLS analysis) between the electronic tongue and the physicochemical parameters was found, the best results being for color Pfund (r² = 0.958), L^∗ (r² = 0.935) and diastase activity (r² = 0.926). The correlation with volatile compounds was much weaker, though this improved for specific characteristic compounds in each monofloral variety. Thus, this is a good starting point for the development of new systems focused on the honey sector.     

Rapid whole protein quantification of staphylococcal enterotoxin B by liquid chromatography

Food poisoning caused by Staphylococcus aureus is one of the most important foodborne diseases in the world. The ability of these bacteria to produce one or more enterotoxins in milk and dairy products is linked to staphylococcal food poisoning. Enterotoxin B (SEB) is an exotoxin produced by S. aureus and is one of the compounds most frequently involved in staphylococcal food poisoning worldwide. In this work, 20 samples of milk collected from restaurants have been studied for the presence of S. aureus enterotoxigenic strains. All the isolates from milk samples have been analysed by liquid chromatography-coupled with diode array detector for the rapid identification and quantification of SEB as intact protein. Limit of detection and limit of quantification values were 0.5 and 1 μg/mL, respectively. S. aureus was found in 35% of analysed samples but only one of them was an enterotoxigenic strain, which produced staphylococcal enterotoxin B at levels of 3.6 μg/mL.     

Model organisms in molecular nutrition research

The complexity of food organism interactions necessitates the use of model organisms to understand physiological and pathological processes. In nutrition research, model organisms were initially used to understand how macro and micronutrients are handled in the organism. Currently, in nutritional systems biology, models of increasing complexity are needed in order to determine the global organisation of a biological system and the interaction with food and food components. Originally driven by genetics, certain model organisms have become most prominent. Model organisms are more accessible systems than human beings and include bacteria, yeast, flies, worms, and mammals such as mice. Here, the origin and the reasons to become the most prominent models are presented. Moreover, their applicability in molecular nutrition research is illustrated with selected examples.     

Current Status on <Emphasis Type="Italic">Arcobacter</Emphasis> Research: An Update on DNA-Based Identification and Typing Methodologies

In the last few years, species of the genus Arcobacter have emerged as etiologic agents of food-borne diarrhoeal illness in humans. The routes of Arcobacter spp. infection are not yet elucidated, but consumption of contaminated food and water seem as the most likely vehicles for the transmission to persons. Food commodities from which arcobacters are more frequently isolated are meats, especially poultry followed by pork, beef and others. The growing number of reports alluding to the association of Arcobacter spp. with animal foods and human illness has concentrated efforts of researchers towards the development of improved molecular methods for the identification and characterisation of these emerging pathogenic bacteria. In this review paper, an update of the occurrence of arcobacters in foods and their association with human illness is provided. Special emphasis is given to the main DNA-based methods applied for the detection and identification of Arcobacter species, as well as to the molecular typing methods currently in use for these emerging food-borne pathogens.     

Vibrational spectroscopic analysis of hake (Merluccius merluccius L.) lipids during frozen storage

Vibrational spectroscopy (mid FTIR and FT-Raman) was used to monitor lipids extracted from hake fillets during frozen storage. Kramer shear resistance was used as a marker of texture changes and lipid damage was also investigated by following the development of conjugated dienes and free fatty acids by spectrophotometric methods. Results show that the intensity of the free fatty acid carboxylic ν(CO) band measured by ATR-FTIR spectroscopy can be used for monitoring the development of lipid hydrolysis in hake lipids. Changes in the Raman ν(CC) stretching region (1658 cm⁻¹ band), partially attributed to conjugated dienes development, were the only observed spectroscopic alterations related to lipid oxidation of hake lipids during frozen storage at −10 °C. The high correlation of free fatty acids with instrumental texture and the disappearance of the ν_as(PO₂⁻) band are consistent with membrane lipid hydrolysis being one of the factors directly related with toughening of lean fish flesh.