Aroma profile and physico‐chemical properties of artisanal honey from Tabasco,Mexico

The aim of this work was to characterise, physico‐chemically, sugar composition and aroma profile of ten honey samples collected by small producers during two seasons and produced in different agricultural ecosystems from Tabasco State (Mexico). The mean values obtained for the physico‐chemical parameters were: pH 3.63; 19.25% moisture; 78.8°Brix sugar; 0.64% ash; 0.25 mS cm^?1 electrical conductivity and 0.58 water activity. Based on colour parameters, Tabasco honeys can be placed in the group of dark honeys. In the analysed samples; fructose was the major sugar (39.45%), followed by glucose (35.74%) while sucrose only represented 2.93%. The volatile profiles of the ten honey samples were obtained by gas chromatography‐mass spectrometry. All the honeys were characterised by their high contents of benzene and furan‐related compounds. As a result, artisanal honeys from Tabasco (Mexico) can be considered to present a good level of quality.     

香奈儿背话的家族

“我们是一个很谨慎的家族．（对香奈儿）我们从来不说什么。香奈儿是关于可可·夏奈尔的，是关于卡尔的，是关于每一个在香奈儿工作、创作的人的．而不是关于维德摩尔家族的。”     

Automatic provision of personalized e-commerce services in Digital TV scenarios with impermanent connectivity

Digital TV (DTV) bears much potential for e-commerce, but most of it remains underexploited due to the lack of systematic approaches to the provision of interactive applications. Working on top of an existing recommender system, this paper presents mechanisms to automatically compose applications that provide personalized commercial functionalities to the users. The proposal addresses specific concerns of DTV environments, with special attention to achieving good personalization quality and furnishing useful interactions when there is no return channel permanently available for bidirectional communication. Preliminary experiments reveal good acceptance of the concept among real users.     

Control of the Basicity in Ni–MgO Systems: Influence in the Hydrogenation of Styrene Oxide

The addition of basic solutions to the reaction medium in the catalytic hydrogenation of styrene oxide improves the selectivity to 2-phenylethanol (used in perfumery) but also can favour condensation reactions. To study the influence of different basic sites on the reaction products, we prepared several catalysts by mixing a commercial magnesia (MgO), and other previously rehydrated (MgOr), with different amounts of NiO followed by reduction (NiMgO, 4NiMgO, NiMgOr, 4NiMgOr), and by mixing directly MgO with Ni (NiMgOa, 4NiMgOa). Ni–MgO catalysts showed the best conversion and selectivity to 2-phenylethanol values, arriving to 100% when increasing the MgO content. Interestingly, CO₂-TPD study of catalyst NiMgO indicates that metallic nickel covers the weakest basic sites of magnesia. On the other hand, CO₂-TPD profiles of Ni–MgOr and Ni–MgOa catalysts, which present low catalytic activity, showed an important amount of available basic sites that favour the formation of higher amounts of condensation products, which are responsible for the catalyst deactivation.     

Role of drawing-induced residual stresses and strains in the hydrogen embrittlement susceptibility of prestressing steels

Hydrogen embrittlement (HE) of prestressing steel is a major technological problem in damage tolerance and structural integrity of structures in harsh environments, it being strongly influenced by residual stresses and plastic strains after cold-drawing. This paper calculates the distributions of such variables (mechanical approach) and later the stress-and-strain assisted diffusion of hydrogen (chemical approach) in a real manufacturing process by multi-step cold drawing. Results confirm the relevant role of plastic strain in HE of prestressing steel and thus the necessity of considering it in hydrogen diffusion calculations, because stress-only assisted diffusion leads to dramatic (and non conservative) underestimation of the hydrogen content.     

An Overview of Biological Macromolecule Crystallization

The elucidation of the three dimensional structure of biological macromolecules has provided an important contribution to our current understanding of many basic mechanisms involved in life processes. This enormous impact largely results from the ability of X-ray crystallography to provide accurate structural details at atomic resolution that are a prerequisite for a deeper insight on the way in which bio-macromolecules interact with each other to build up supramolecular nano-machines capable of performing specialized biological functions. With the advent of high-energy synchrotron sources and the development of sophisticated software to solve X-ray and neutron crystal structures of large molecules, the crystallization step has become even more the bottleneck of a successful structure determination. This review introduces the general aspects of protein crystallization, summarizes conventional and innovative crystallization methods and focuses on the new strategies utilized to improve the success rate of experiments and increase crystal diffraction quality.     

Application of anaerobic membrane bioreactors for the treatment of protein‐containing wastewaters under saline conditions

BACKGROUND: Anaerobic treatment of saline wastewaters may be hindered by problems related with biomass retention, since at high salt concentrations formation of biofilms and granules may not proceed well. This research studied the use of anaerobic membrane bioreactors (AnMBR) as a way to promote complete biomass retention. A lab scale AnMBR fitted with a ceramic tubular membrane was operated for 2 years. RESULTS: Results showed that enhanced biomass retention produces conditions enabling anaerobic treatment of saline wastewaters. Despite the high resulting sludge retention time, no accumulation of a high proportion of dead cells was observed. Protein degradation and not methanogenesis was shown to be the rate limiting step for organic matter degradation, a fact that is relevant for protein‐containing wastewaters such as those from seafood processing industries. Only low levels of flux could be applied, in the region of 5 L m^?2 h^?1 due to reversible cake formation promoted by single cell growth. CONCLUSION: Biomass retention provided by membrane filtration promotes conditions suitable for efficient treatment of saline wastewaters. However, operation may be restricted to low values of flux due to biomass development as single cells. © 2012 Society of Chemical Industry     

Effect of sterilisation on dietary fibre and physicochemical properties of onion by-products

Food industries are forced to develop productions without secondary residues. Therefore, there is a considerable emphasis on the recovery, recycling and upgrading of wastes. The possibility has been suggested for the conversion of onion waste into food ingredients, but with a stabilisation treatment being necessary. The objective of this work was to study the effect of sterilisation on fibre fractions, fibre composition and physicochemical properties of onion by-products to evaluate the use of sterilised onion by-products as a source of fibre.     

Vicilin and the basic subunit of legumin are putative chickpea allergens

IgE-mediated reactions to food allergens constitute a major health problem in industrialized countries. Chickpea is consumed in Mediterranean countries, and reportedly associated with IgE-mediated hypersensitivity reactions. However, the nature of allergic reactions to chickpea has not been characterized.