Comprehensive characterization of the functional activities of pressurized liquid and ultrasound-assisted extracts from Chlorella vulgaris

Chlorella vulgaris has been referred as a potential source of bioactive compounds (carotenoids and fatty acids). In this work, the ability of an environmentally friendly extraction technique such as Pressurized Liquid Extraction (PLE) and a traditional extraction technique such as Ultrasound-Assisted Extraction (UAE) to obtain functional compounds from C. vulgaris, at analytical scale, has been demonstrated. Seeked bioactivities were antioxidant and antimicrobial, for their interest in the food industry. Therefore, a methodology including analytical extraction, in-vitro assays and chemical characterization via HPLC-DAD and GC–MS has been used to determine the interest of Chlorella as a source of functional food ingredients. Results demonstrated that PLE provide higher yields than UAE while similar bioactivities were obtained. Important concentration of carotenoids (lutein, neoxanthin, β-carotene, etc.), chlorophylls, sterols, phytols, and fatty acids (among others) have been found in Chlorella extracts that could be correlated to the observed biological activity.     

Thermotropic, Thermo-morphologic, and Thermo-optical Properties of New Smectogenic Calamitic Compounds Containing Imine Linking Groups

The synthesis and investigations of the mesomorphic, thermotropic, thermo-morphologic, and thermo-optical properties of two new salicylaldimine compounds, synthesized by our group, are reported in this work. Temperature transformations of specific textures of the smectic C mesophase, taking place in these compounds, and thermo-morphologic and thermotropic properties of the biphasic regions for direct and reverse phase transitions have been investigated. Temperature hysteresis and enlargement of the biphasic regions have been found. The character of texture transformations and temperature behavior of the optical birefringence indicate to the first order a smectic C–isotropic liquid-phase transition in these salicylaldimine compounds.     

Production of human growth hormone by Lactococcus lactis

A synthetic gene coding for human growth hormone was expressed in Lactococcus lactis. The presence of the recombinant protein was assayed and quantified using ELISA tests. Human growth hormone was detected at high concentrations and displayed a biological activity similar to the one shown by commercial human growth hormone.     

Soluble polypyrrole copolymers

A new class of dimethyl formamide (DMF)– and acetone‐soluble conducting pyrrole–ketonic resin copolymers has been developed. This was accomplished by oxidatively polymerizing pyrrole monomer by Ce(IV) salt in the presence of methyl ethyl ketone formaldehyde resin (MEKF–R). The resulting copolymers were readily dissolved in DMF and acetone. These products were characterized by FTIR and UV‐visible spectroscopy, conductivity, four‐probe conductivity, viscosity, and DSC measurements. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1098–1106, 2001     

A hybrid neural model (HNM) for the on‐line monitoring of lipase production by Candida rugosa

A mechanistic model was proposed by Gordillo for the representation of lipase production by Candida rugosa, with the bioreactor in batch and fed‐batch operation. However, the model was not able to represent the lipolytic activity. The objective of the present study is to propose an efficient hybrid neural‐phenomenological model (HNM) for this process. The experimental data used corresponded to fed‐batch operation with constant substrate feed rate at 2.8 × 10^?7; 5.6 × 10^?7 and 9.7 × 10^?7 kg s^?1. Artificial neural networks (ANNs) were trained to represent the aqueous and intracellular lipase activity and were further associated with a reduced version of the mechanistic model of the proposed HNM. When compared to the experimental data, the HNM exhibited higher accuracy. The HNM can be employed in process monitoring using only on‐line measurements of CO₂ and substrate feed rate to infer enzyme activities and also substrate and biomass concentrations. Copyright © 2007 Society of Chemical Industry     

Oxidative polymerization of N‐vinylcarbazole in polymer matrix

A new class of soluble conductive poly(N‐vinylcarbazole) (PVCz) compounds has been developed by oxidative matrix polymerization of N‐vinylcarbazole (NVCz) by Ce(IV) in the presence of poly(ethylene glycol) (PEG). PEG was found to be a more suitable matrix with which to obtain a stable homogenous ternary complex solution when compared with poly(acrylic acid) (PAA) and poly(vinylpyrrolidone) (PVP). The role of PEG, NVCz and Ce(IV) concentration, order of component addition, the structure of the polymer matrix, molecular weight of polymer and the effect of solvent have been investigated. Obtaining soluble PEG–Ce(III)–PVCz ternary complexes was shown by cyclic voltammetric measurements, and the initial rate of formation NVCz cation radicals as calculated using UV–visible spectrophotometry. Advantageously with these soluble complexes, conductivities could be measured both in solution and in the solid state. © 2001 Society of Chemical Industry     

A study of some equation‐of‐state parameters of poly(methylhydrosiloxane‐co‐dimethylsiloxane) with some solvents by gas chromatography

Trace amount of methyl acetate, ethyl acetate, tert‐butyl acetate, pentane, hexane, and heptane were passed through the chromatographic column loaded with poly(methylhydrosiloxane‐co‐dimethylsiloxane) coated on Chromosorb W. The retention diagrams of the solvents on the copolymer were plotted by means of specific retention volumes at temperatures between 40 and 80°C by inverse gas chromatography technique. In this study, some thermodynamic interaction parameters such as Flory–Huggins polymer–solvent interaction parameter, equation‐of‐state polymer–solvent interaction parameter, effective exchange energy parameter, and weight fraction activity coefficients at infinite dilution of the solvent were determined. Then, the exchange enthalpy parameter and entropy parameter were determined by using a relation for the enthalpy interaction parameter of the equation‐of‐state theory, which is arranged for the inverse gas chromatography conditions. Later, the partial molar heat of sorption and the partial molar heat of mixing were obtained. The solubility parameter of this copolymer was determined as 6.64 (cal/cm³)^1/2 at room temperature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1627–1631, 2007     

The use of grape,pomegranate and rosehip seed flours in Turkish noodle (erişte) production

Eri?te is a traditional cereal product in Turkey, which resembles Asian noodles. Since it is a suitable product for enrichment, it was aimed in this study to utilize some fruit processing by‐products to enrich eri?te in terms of antioxidants and to determine the effect of enrichment on physical properties of eri?te. For that purpose, eri?te samples enriched with three different proportions (10, 20 and 30%) of grape, pomegranate and rosehip seed flours were compared with the control group in terms of antioxidant activity, color, cooking, textural and sensory properties to evaluate the effect of enrichment on eri?te quality. It was determined that addition of 10% grape, pomegranate and rosehip seed increased the antioxidant activity of eri?te by 8, 4 and 5.7 times, respectively, as compared with the control. Although the sensory analysis indicate that eri?te enriched with pomegranate seed were mostly liked, antioxidant activity was found lower than the others.

Practical applications

Using by products and wastes of foods like fruit seeds for enrichment is a promising alternative for utilization. Grape, pomegranate and rosehip seeds have very high antioxidant levels with natural antioxidants like proanthocyanidins, resveratrol, tocopherols etc; rich in dietary fiber, also unsaturated and essential fatty acids. For this purpose; cooking, textural, sensory, color and antioxidant properties of enriched samples were compared with traditional Turkish noodle.     

Plant starches and oils. Their influence on digestion in rats

The purpose of the present study was to determine the interaction effect of starch and fat of such products over blood parameters (cholesterol, triglycerides), and to evaluate starch and fat digestibility. Experiments were carried out in eight groups of Sprague-Dawley rats that were under the following diets: four of the groups were fed with a mix of 14% palm oil and 58% of each one of the starches (rice, corn, manioc and green plantain); the other four groups were fed a mix of 14% of corn oil and 58% of each one of the same starches under study. No significant differences were found in liver weight or fat digestibility among the groups of study. Significant differences were found on the starches digestibility, the green plantain starch being the one with the lowest digestibility (83–97%). The statistical differences showed an interaction between the starch and oil that affects the starch present in faeces and the starch digestibility. The evaluation of the blood parameters (cholesterol and triglycerides) showed significant differences when different starches were fed, but no so, when oils were changed. Animals that were fed manioc starch showed a higher concentration of cholesterol and triglycerides (244–150 mg dl⁻¹), while animals that ingested green plantain starch showed the lowest concentration (93–150 mg dl⁻¹). Our results suggest that the levels of cholesterol in rats was probably influenced by the digestibility of the starches present on the diet. The statistical analysis showed a high interaction starch vs oil over plasmatic triglycerides concentration. The green plantain starch has the same effect as some of the resistant starches. © 1998 SCI.     

Why is Brazil enriching uranium?

In Brazil construction began in 1971 on Angra 1, a 626 MW Westinghouse pressurized water reactor (PWR). It was completed in 1984. Later, Angra 2 (a Kraftwerk Union PWR) achieved commercial operation in 2000. Brazil is considering the construction of seven nuclear power plants over the next 15 years. In preparation for this nuclear industry expansion, Brazil is building a uranium enrichment facility to provide nuclear fuel for Angra 1 and 2 starting in 2010 at Resende in the state of Rio de Janeiro, and collated with nuclear fuel fabrication facilities. This paper investigates whether the Resende Enrichment Facility will be able to provide uranium enrichment services at a cost lower than the international market price. We find that while Brazil is unlikely to be internationally competitive in the enrichment market, the Resende Enrichment Facility completes the front end of Brazil's nuclear fuel cycle. This assures uninterrupted nuclear fuel to its currently operating light water reactors, while providing the option of expanding capacity, lowering cost, and competing in the international nuclear fuel market after 2020.