Volume 10, No. 1 (2009)
Articles
PHOTOINDUCED PHENOMENA AND MECHANISMSIN PHOTOCHROMIC MATERIALS
IONICA IONITA(1*), ANA-MARIA ALBU(2), CRISTIANA RADULESCU(1), ELENA IRINA MOATER(1)
The incorporation of photochromic molecules by physical way (dissolution, dispersion) or chemical way (covalent bond) in organic chains (particularly polymers) or organic-inorganic hybrids leads to the development of a new class of materials, named photochromic materials. These photochromic materials have applications in the unconventional optic area, their properties being shaped with the help of light. The properties’ shaping doesn’t referred merely to spectacular modifications of detected macroscopic color, but also and to same of series of microscopic properties which are variable in the course of these energetic transitions. In the application field based on photochromia, the most used photochromic materials are the azo derivatives. The interest for this class of compounds is justified on a side through the thermal and chemical stability, the easiness of the azo sequences generation, as well as through versatility of this sequences at action of energetic stimuli.
[Cy2NH2SO4(SnPh3)2X]2 (X = F, Cl): SYNTHESIS AND SPECTROSCOPIC STUDIES
KOCHIKPA Y. A. OKIO(1), LIBASSE DIOP(1*), UMBERTO RUSSO(2)
Two new tetranuclear (sulphato)(halo)triphenyltin(IV) complexes (halo = F, Cl) have been synthesized and studied by infrared and Mossbauer spectroscopies. The suggested structures are discrete, the anion acting as a bichelating, a monochelating and monocoordinating or a bidentate ligand. The key role of the cation, which appears to link the two components of the structures via hydrogen bonds, is noteworthy.
A NEW RESEARCH ON THE BIOLOGICAL ACTIVITY OF (2S,3S)-1,4-BIS-SULFANILBUTANE-2,3-DIOL
CORINA TOADER(1), IRINA ZARAFU(2)*, ION BACIU(2)
The universal sample processing multipurpose methodology was not developed for the diagnosis of tuberculosis. We have recently described a sputum specimen processing method that involved homogenization and decontamination of the specimens by a treatment with dithiothreitol [(2S,3S)-1,4-bis-sulfanilbutan-2,3-diol] [1, 2]. This enable a highly sensitive smear microscopy and a better isolation of M. tuberculosis, showing, for the first time, the usefulness of dithiothreitol in TB laboratories. This report describes a study which was carried out to determine the effects of centrifugal force and centrifugation time on the concentration of mycobacteria in clinical specimens liquefied with dithiothreitol. The effect of increasing centrifugal force was evaluated by AFB smear sensitivity in a study of 80 sputa that contained AFB, picked from routine submissions, and also by recovery rates of M. tuberculosis from sputa, in this case we performed 10 determinations using AFB smear negative sputa that were sterilized and artificially seeded with known concentrations of Mycobacterium tuberculosis, strain H37Rv.
RESEARCHES REGARDING THE OBTAINING OF YEAST EXTRACTS THROUGH AUTOLYSIS AND HYDROLYSIS WITH ADDITION OF EXOGENOUS ENZYMES
MARIA IORDAN(1*), ALEXANDRU STOICA(1), AURELIA IONESCU(2)
This work presents the experimental results regarding to obtaining of bakery yeast extracts through exclusion of plasmolyse with NaCl. It was used exogenous proteolytic and cellulolytic enzymes for an easy release of cell yeast constituents. It was tested the extent of the yeast cell wall destruction by different exogenous proteolytic or cellulolytic enzymes. Also, it was compared different technological variants to obtain the yeast extracts using exogenous enzymes and characterized the obtained yeast extracts from sensorial and chemical point of view. The bakery yeast autolysis associate with enzymatic hydrolysis using exogenous enzymes lead to a suitable release of protoplasmic constituents, the yeast extracts containing more than 60% from cellular nitrogen. The chemical characteristics of concentrated yeast extracts obtained through autolysis and enzymatic hydrolysis and its flavor profile were dependent by the nature of exogenous added enzyme, these having increased quality characteristics in comparison with the extract obtained only through autolysis.
EVALUATION OF HYGIENIC AND NUTRITIONAL QUALITY OF PEULH CHEESE TREATED BY SORGHUM VULGARIS (L) AND PIMENTA RACEMOSA (MILLER) EXTRACTS
MARTIN KEKE(1), BONIFACE YEHOUENOU(1), COMLAN DE SOUZA(2), DOMINIQUE SOHOUNHLOUE(1*)
The present study has been carried out for evaluating hygienic and nutritional quality of treated Peulh cheese using Sorghum vulgaris and Pimenta racemosa extracts. After the treatment of cheeses with the two extracts, a significant reduction of the microbial flora occurs during the conservation. It seems however worthy that combining temperature and extracts is necessary. The decrease of pH values of fresh cheeses compared to those of treated ones has been observed and connected to the amount of lactic acid present (0.17% for fresh cheese and 0.21% for treated ones). It results a lowering of the pH values of fresh cheeses and those treated with extracts are respectively 6.47 and 6.08. Titrable acidity values as a percentage of lactic acid, which is related to the pH values. The amount of water in studied cheeses decreases from 64.02% to 58.37% leading to a reduction in their osmophile flora. In nutritional terms, there is a conservation of lipid level (47.20%), protein (38.56%) and an increase of ash (minerals) from 4.23% to 5.21% in treated cheeses. These results indicate an important cheese quality improvement in hygienic and level, induced by conservation.
A STUDY CONCERNING THE INFLUENCE OF THE NATURAL PRESERVATIVES UPON THE COLOUR OF THE LACTO-FERMENTED BEETROOT JUICE
IULIANA MANEA(*), CORINA POPESCU
The purpose of this study is to point out the transformations that the color of beet root juice undergoes during the lactic fermentation in the presence of some additional elements that have a preservative and diluting function. The juice was obtained through the processes of chopping and pressing of the red beetroot, then it was diluted up to 5/1 with black radish, parsnip and celery juice. Other two samples have been preserved with sodium benzoate and garlic. The inoculation was made with brine inoculums with 105 cells/mL lactic bacteria mixture. The lactic acid fermentation was performed in a thermostat at 27±2 °C, during 7 days. Meanwhile the color intensity, the pH and the titrable acidity have been determined. There has been noticed a lowering of the color intensity for all the samples. In comparison with the approval sample, the samples that have been preserved with sodium benzoate and garlic were more stable as far as the color is concerned with an extinction of ESB = 0.275 respectively ESU = 0.295. There has been noticed a prominent alteration of the color intensity in case of the samples diluted with black radish, parsnip and celery juice (EM = 0.220, EST = 0.170, ESP = 0.180, ESR1 = 0.210, ESR2 = 0.180).
THE INFLUENCE OF THE BREAD MAKING PROCEDURE ON THE IRON BIOAVAILABILITY
RODICA STURZA(1), VALENTIN GUDUMAC(2), OLGA DESEATNICOV(1), CORINA CIOBANU(1)
The aim of the present study was the investigation of the influence of the bread making method on the iron bioavailability in the iron fortified bread. The enzymatic degradation of the phytates (InsP6) was studied within gastro-intestinal digestion conditions in vitro. The study of the iron bioavailability was drowning in vitro, according to the Monsen model, and in vivo on white laboratory rats. The study of the biochemical indices of the blood, collected from the laboratory animals, fed with fortified bread with 8 mg Fe/100 g product, made by the traditional method and by the lactic-acid fermentation method compared to the control group showed that iron intake plays conclusive role in animal nutrition. Thus, iron statute of both experimental groups, and especially iron reticence in the body, was essentially improved compared to the control group.
PREVENTION OF ENVIRONMENTAL POLLUTION BY SUPERIOR RENDERING OF PIG SKINS RESULTING FROM PIG SLAUGHTERING
IULIAN SUCEVEANU(1)*, MIRELA SUCEVEANU(2), DOMNICA CIOBANU(2)
The meat industry, besides meat – as a main product –, there are a lot of secondary products, which have a remarkable economical importance when they are properly analyzed. The rendering of pig skin implies the following changes: (1) Adoption of new scalding-skinning technology of processing, so that the removal of rind from the carcass should have place directly into the carving room. The result is a maximum quantity of rind, under the imposed sanitary-veterinary conditions. (2) The optimization of the scalding-skinning technology, so that the detachment of the pig skin to be done completely, without causing great quantities of offals. (3) The organization of the rind technological process: the rind elimination from the carving room by refrigeration, peeling, boiling, cutting. The result is the rind emulsion. (4) The production of the rind emulsion is a modality of superior rendering of pork skin. The rendering of the rind offers the following advantages: (1) The increase of the alimentary yield with approximately 10% (from 82% up to 92%); (2) The increase by 300% of the economical value by rind rendering; (3) The decrease of salt consuming, used for the salting of pork skin; (4) The superior rendering of the technical lard resulting from the rind peeling the result is the increase of the alimentary yield from 4% up to 92%.
THE LIQUID-CHROMATOGRAPHIC QUANTIFICATION OF SOME SYNTHETIC COLORANTS IN SOFT DRINKS
ION TRANDAFIR(1)*, VIOLETA NOUR(2), MIRA ELENA IONICA(2)
A simple, selective, and precise reversed-phase HPLC method with "diode array" detection has been developed, enabling separation and quantification, in a single run of tartrazine (E 102), amaranth (E 123), erythrosine (E 127) and indigotine (E 132) in soft drinks. HPLC was performed with a Surveyor Thermo Electron system and the reversed phase chromatographic separation was achieved at 30 °C, using a DS Hypersil C18.5 ?m column and a mobile phase made of 100 mM sodium acetate buffer and acetonitrile. Through optimization studies they were established: the gradient program of the elution, the injected volume 5 µL, the flow rate of the mobile phase 1mL/min, the duration of the analysis being 30 min. The synthetic colorants were detected by absorbance at ? = 430 nm for tartarzine, ? = 520 nm for amaranth and erythrosine and ? = 608 nm for indigotine. The method was validated in terms of sensitivity, linearity range, reproducibility, repeatability, analytical recovery and robustness.
THE EVOLUTION OF CERTAIN PHYSICAL-CHEMICAL PARAMETERS OF THE WATER USED FOR THE PROVISIONING OF THE AQUATIC ECOSYSTEM BRATES
AIDA VASILE(1)*, MARGARETA ZARA(1), ELPIDA PALTENEA(2)
The physical-chemical properties of the water are defined by multiple parameters. The most important parameters for the fish’s life are the pH, dissolved gases, suspended organic matter, ammonia content, nitrites, nitrates, phosphates, chlorides, hydrogen sulfide, metals, and detergents. Romanian Standard STAS 4706/1988 presents the water quality indicators values. In accordance with these indicators, the surface waters are divided into three quality categories. By the written disposition no. 1146/2002, the water quality parameters values used for aquaculture fish breeding and the second category were bring up to date. Because of this reason, in this project it is compared the evolution of the main chemical parameters of the supplied water from Danube and Brates lake and used for the anthrop aquatic ecosystem – Brates in the period 2002-2005. There were examined water pH, dissolved oxygen content (mg/L), decomposing organic matter (mg of KMnO4/L of water), ammonia (mg of NH3/L of water) and nitrites (mg of NO2-/L of water), parameters which indicate, in the situation of exceeding of the admissible limits for culture cyprinids, that there are possible some pathological states at fish. [1 - 3]. Comparing the same water parameters values for the two supply sources, the Danube and Brates Lake, we can see a visible difference. The Brates lake water has a bad quality and it is not indicated for the aquaculture use.
MICROBIOLOGICAL TREATMENT OF WATERS FROM PAPER MILLS CIRCUITS
CONSTANTIN STANCIU
Microbiological aspect of paper making relates to slime issues. They are made of jellylike matter that build-up in process water circuits of paper mills. Water circuit of paper mills provides good conditions of microorganism development (nutritive substances, temperature, pH and oxygen). High contents of microorganisms are noticed on paper circuits that are able to reach up to 107 CFU/mL. The most common microorganisms are bacteria often joined by fungi and yeasts. The signs of infections that frequently occur in a paper mill are the following: a. Formation of slime; Microorganisms tend to attach on water circuit walls as biofilms; b. Felt plugging and foulness; c. Glue and starch damage; d. Stains and coloration; e. Cellulolitic action; f. Localized corrosion and odor (H2S). The first section of the paper shows the physical proprieties of sludge and slime (biological slime, chemical slime, chemical-biological slime). As a general rule, slime that is found in paper machines is a complex, chemical and biological slime. Biofilm deposits on water circuit walls are mainly made of bacteria and extra-cellular polysaccharides (EPS). Bacteria attach to walls, by means of protean filaments. Values of microbiological contamination and efficiency of using various biocides in the alkaline and acid processes are shown. We notice the efficiency of DILURIT 953 biocide, in the alkaline process (pH = 4-8, charge 200 g/ton of paper) that leads to reduction of bacteria number by 82.3%. The activity of DILURIT 953 is extended to all families of contaminants (bacteria, moulds, yeasts, and sulfate reducing bacteria - SRB). Paper mills are facing problems not with the number of microorganisms in the system, but with the volume of slime on walls.