Extraction of caffeine from natural matter using a bio-renewable agrochemical solvent

This paper reports experimental data on the pressurized liquid extraction of caffeine from green coffee beans and green tea leaves using ethyl lactate (ethyl 2-hydroxy-propanoate). This solvent is a new bio-renewable agrochemical solvent, naturally produced by fermentation from corn derived feedstock, which has been recently considered as a very suitable and environmental benign solvent for food industrial applications.Static extraction assays (one step during 10 min) were carried out in an Accelerated solvent extraction (ASE) system at three different extraction temperatures, namely 100, 150 and 200 °C. Extraction yield and caffeine recovery were determined and compared with those obtained when using other liquid solvents, such as ethyl acetate or ethanol. High recovery of caffeine (≈60%) was found in the extracts produced using ethyl lactate, which demonstrates the potential use of this green solvent for the extraction of caffeine from different vegetable sources.     

Physicochemical Properties of Wheat Gluten Proteins Modified by Protease From Sierra (Scomberomorus sierra) Fish

The effect of semi-purified trypsin on the physicochemical properties of durum and bread wheat flour and gluten protein fractions was evaluated. Trypsin was partially isolated from sierra (Scomberomorus sierra) guts extracts by affinity chromatography. Treatment with enzyme caused hydrolysis of 1.16–1.40% in both durum and bread wheat gluten and gluten fractions. The effect of hydrolysis on the isoelectric point was more evident in durum that bread wheat gluten. Addition of the trypsin-like enzyme at three different concentrations induced a decrease in the gluten index. The dough consistency fell after 1.5 h of incubation. It was possible to modify wheat flour proteins by varying S. sierra trypsin-like enzyme concentration and incubation time, depending on the wheat species.     

Safe lithium-ion battery with ionic liquid-based electrolyte for hybrid electric vehicles

A lithium-ion battery featuring graphite anode, LiFePO₄-C cathode and an innovative, safe, ionic liquid-based electrolyte, was assembled and characterized in terms of specific energy and power after the USABC-DOE protocol for power-assist hybrid electric vehicle (HEV) application. The test results show that the battery surpasses the energy and power goals stated by USABC-DOE and, hence, this safe lithium-ion battery should be suitable for application in the evolving HEV market.     

Synthesis of Hydroxylated Biphenyl Derivatives Bearing an α,β-Unsaturated Ketone as a Lead Structure for the Development of Drug Candidates against Malignant Melanoma

A small collection of C₂-symmetric hydroxylated biphenyl derivatives featuring an α,β-unsaturated ketone as a lead structure was prepared, and the capacity of these compounds to act as antiproliferative agents against four human malignant melanoma cell lines was assayed. The prodrug approach was applied in order to improve the delivery of compounds into the cell by modulation of the phenolic hydroxy protecting group. The hydroxylated biphenyl structure bearing an α,β-unsaturated ketone and a phenolic-O-prenylated chain was found to facilitate the delivery of the molecule and interactions with biological targets. Four compounds showed antiproliferative activity resulting in IC₅₀ values in the range of 1.2 to 2.8 μM.     

Towards a competency model for requirements analysts

Requirements engineering is a software development discipline, executed by requirements analysts (RAs), that includes requirements elicitation, analysis, specification and validation. Its successful outcome is very often essential to overall project success. However, there is a lack of systematically conducted empirical research on the competencies of RAs. This paper addressed this gap by conducting 64 interviews at eight major North American and European financial services companies. Our qualitative research design follows an interpretive approach and uses critical incident technique. We develop a competency model, which specifies 16 critical competencies, and integrates contextual and situational factors as well as results variables. ‘Consulting others’, ‘Testing assumptions and investigating’ and ‘Explaining concepts and opinions’ were the most frequently identified competencies. This indicates that for an effective analyst, close interaction and communication with customers is indeed crucial – but of equally importance is the critical questioning of the expressed needs. Surprisingly, applying specific tools and advanced techniques did not seem to play a significant role from the interviewees' perspective. This study contributes to theory as it is the first to elaborate a competency model for RAs. It also provides a foundation for the development of competency‐based training in companies and universities.     

Biodiesel Production using Lewis Catalysts under Ultrasonic Activation

Biodiesel can be produced by transesterification of oil triglycerides, as well as by esterification of fatty acids using feedstock materials rich in free fatty acids)FFAs). Utilization of such feedstocks can gain substantial economical profit and solve a problem of disposal of residual raw materials. To find an effective method of biodiesel production from FFA, we developed esterification of FFAs under ultrasonic activation using Lewis acids as catalysts. Homologous catalyst BF₃ and heterogeneous AlCl₃ were highly effective in reactions of model FFAs methylation under ultrasonic activation, when the reaction yield reached 100 %. Ethylation at the same conditions was less successful.     

Spectral coded phase bipolar OCDMA technological implementation thanks to low index modulation filters

Telecommunication Systems - Optical code division multiple access (OCDMA) systems are attracting an increasing interest in optical fiber communication. This is due to the various advantages that...     

Proteomic identification and physicochemical characterisation of paramyosin and collagen from octopus (Octopus vulgaris) and jumbo squid (Dosidicus gigas)

To perform improvements in food science, it is fundamental to understand the physicochemical properties of proteins since their interaction with other macromolecules plays an essential role in food systems. Collagen and paramyosin help in the maintenance of the matrix structure cells, the textural behaviour and the technical functionality of the protein concentrates; because of this, their identification and characterisation are necessary. Cephalopods species have shown differences in the distribution of its muscle fibres. The amino acid profile of jumbo squid showed a high content of glycine and hydroxyproline, while octopus showed a high content of acidic amino acids. The thermal profile of jumbo squid showed an endothermic transition at 117 °C, which octopus did not present. Moreover, the proteomic identification confirms the identity of paramyosin with 33% coverage to paramyosin from Dosidicus gigas and a 4% coverage to collagen type II from Sepia pharaonis on octopus and jumbo squid, respectively.     

Lysyl oxidase from jumbo squid (Dosidicus gigas) muscle: purification and partial characterization

Lysyl oxidase (LOX; E.C.1.4.3.13) was purified from jumbo squid muscle (Dosidicus gigas) with 1900‐fold and yield 1.9%, and characterized for the first time. The purification procedure consisted of fractionation with urea and a combination of size‐exclusion and anion‐exchange chromatography. The enzyme had a molecular weight of 32 kDa, as estimated by SDS‐PAGE. Using a specific LOX substrate (1,5‐diaminopentane), its optimum activity was determined at pH 8.2 and 65 °C. Activation energy (E_a) of the enzyme was 69.94 kJ K^?1 mol^?1. The enzyme was strongly inhibited by β‐aminopropionitrile fumarate (BAPN), a specific LOX inhibitor. Moreover, purified LOX was able to work at different temperatures (20–90 °C) at pH 8.2. Although further research is needed, the results from this work suggest that based on LOX activity, this enzyme may be of practical use in preventing textural changes in jumbo squid during storage or processing.     

An Advanced Apralog with Increased in vitro and in vivo Activity toward Gram-negative Pathogens and Reduced ex vivo Cochleotoxicity

We describe the convergent synthesis of a 5-O-β-D-ribofuranosyl-based apramycin derivative (apralog) that displays significantly improved antibacterial activity over the parent apramycin against wild-type ESKAPE pathogens. In addition, the new apralog retains excellent antibacterial activity in the presence of the only aminoglycoside modifying enzyme (AAC(3)-IV) acting on the parent, without incurring susceptibility to the APH(3’) mechanism that disables other 5-O-β-D-ribofuranosyl 2-deoxystreptamine type aminoglycosides by phosphorylation at the ribose 5-position. Consistent with this antibacterial activity, the new apralog has excellent 30 nM activity (IC₅₀) for the inhibition of protein synthesis by the bacterial ribosome in a cell-free translation assay, while retaining the excellent across-the-board selectivity of the parent for inhibition of bacterial over eukaryotic ribosomes. Overall, these characteristics translate into excellent in vivo efficacy against E. coli in a mouse thigh infection model and reduced ototoxicity vis à vis the parent in mouse cochlear explants.