Volume 9, No. 4 (2008)
Articles
RESPONSE SURFACE METHODOLOGY USED FOR THE OPTIMIZATION OF THE FLAVONOID EXTRACT OBTAINING TECHNOLOGICAL PROCESS
FLORENTINA N. RONCEA(1*), RADU G. CAZACINCU(2)
The objective of this work was to use Box – Wilson experimental plan to establish the relation between two dependent variables (Y1 (total polyphenols) and Y2 (antioxidant capacity mM TROLOX/g extract)) and independent variables X1 (vegetal product/solvent ratio), and X2 (hydrolysis time) in order to obtain the optimal formula of the technological process using the response surface methodology (RSM). The optimal formula represents one or two formula (solutions of the system) that analyzed the correspondence with the predicted values. To calculate the coefficients for the response equation we used a software running under Excel. For the optimal formula of the technological process we used Matlab 6.5 version (for plots) and for superimposing the Adobe Photosmart – Acrobat Reader software. Statistics ("t" Student test) were generated through the Excel software. The estimation error values prove the validity of the mathematical method used. The vegetal product/solvent ratio (mass/volume) is 9.25, the hydrolysis time is 18 hours. These solutions correspond to the optimal value and are statistically validated. The software used is running under Windows and could be used for other formulations as well.
CELLULOSIC MATERIALS FOR BIOTECHNOLOGICAL SEPARATIONS
DANIELA SUTEU(1*), VALERIA-MARTA GORDUZA(2), CAMELIA OLTEANU(2), OVIDIU TOMA(3)
New cellulosic materials functionalized with reactive dyes and metallic ions are of interest in affinity separation of enzymes. The purpose of this work is to present a review of our research activities, concerning the opportunities of cellulosic sorbents modified with reactive dyes and/or metallic ions to use in retention of biochemical compounds. We study the retention of lysozyme onto GE and AE microcrystalline ion exchange celluloses unmodified and functionalized with dye Reactive Red 120 and/or Cu2+ ions. The retention capacities of tested materials were evaluated by value of sorption capacity calculated using Langmuir parameters. The results of this study evidenced that celluloses materials tested proved to be an effective sorbent in retaining of proteic compounds traces from aqueous media. In the same time it was established the higher capacity of cellulose ion exchange for lysozyme uptake than that of the same cellulose modified with dye and Cu2+ ions.
P(HEMA) - APPLICATION IN THE TISSUE ENGINEERING OF THE ARTICULAR CARTILAGE
LUCIANA BOSTAN(1*), MARCEL IONEL POPA(1), LILIANA VERESTIUC(2), FLORIN MUNTEANU(2)
The extent of the osteo-articular diseases carried out, in the last decades, to the development of new surgical and prosthetic techniques of treatment. Many studies focused on polymeric materials with the purpose to replace the articular cartilage or to optimize the articular prostheses. Some of this materials allow the regeneration of the articular cartilage: VAP (polyalcohol vinyl), HEMA (hydroxyethyl metacrilate) etc. The choice of these biomaterials is difficult to make because they must to have the same structure and to reproduce the mechanical and physicochemical properties of the biological tissue, in this case, the articular cartilage. The paper presents the experimental results about mechanical properties of poly(HEMA) hydrogels. The influence of a highly hydrophilic monomer AA (acrylic acid), included by co-polymerization into hydrogels structure, on their mechanical properties were analyzed. The results obtained show that poly(HEMA-AA) are promising materials for tissue engineering of cartilage.
A TECHNIQUE TO IMMOBILIZE TRYPSIN ON STAINLESS STEEL IN ORDER TO PREVENT BIOFILMS FORMATION
LUCICA BARBES(1*), MICHELE SALMAIN(2), GABRIELA STANCIU(1)
The molecular mechanisms governing the formation of biofilms by the colonization of solid surfaces with living organisms such as bacteria, algae and eukaryotic cells, are poorly known, in spite of their importance in the medical devices, the food-processing industry and the marine equipments. The aim of this work was to explore different pathways to attach in a covalent manner commercial trypsin to stainless steel coupons to create a thin layer of active enzyme. Different reagents such as functionalized trialkoxysilanes compounds [γ-(aminopropyl)trietoxysilane] has been use to create a reactive molecular layer to attach proteins. The surfaces were characterized after each treatment by Fourier transform infrared reflection-absorption spectroscopy (FT-IRRAS technique) to determine the molecular composition of the films. Finally, the efficiency of the different ways immobilization technique have been assessed by enzymatic assays with selected substrate (N-benzoyl-L-arginine-ethyl-ester – BAEE), then on microbial cultures generating biofilms. The immobilized trypsin exhibited much higher relative activity than lysozyme in the similar conditions.
KINETICS OF THE RELEASE OF KETOPROFEN INTERCALATED INTO LAYERED DOUBLE HYDROXIDES<br/> LA CINETIQUE DE LA LIBERATION DU KETOPROPHENE INTERCALE DANS LES HYDROXYDES DOUBLES LAMELLAIRES
MIHAELA SILION, MARCEL IONEL POPA(*)
The paper presents the intercalation of ketoprofen into layered double hydroxide by the reconstruction and ion-exchange methods. The structure and composition of the intercalated material have been studied by X-ray diffraction (XRD) and FTIR spectroscopy. Drug release from the intercalation compound was performed in vitro in simulated fluid at pH 2.0 and pH 7.4. The kinetic analysis shows the importance of the diffusion through the particle in controlling the drug release rate.
ASPECTS CONCERNING SOIL POLLUTION CAUSED BY THE AGRICULTURE IN THE SOUTH-EAST OF ROMANIA<br/> ASPECTS CONCERNANT LA POLLUTION DU SOL PROVOQUE PAR L’AGRICULTURE DANS LE SUD-EST DE LA ROUMANIE
NICOLETA ROADEVIN
Relation of agriculture with the environment is a divalent relationship: of with dimensions, agriculture is subject to the negative influence of a polluted environment but, at the same time, agriculture even, contributes, as a factor of pollution, with the impoverishment of the soil. Degradation of the soil has multiple causes if it for the factory that is established agricultural realization. In the first part of the work is presented the soil distribution in categories of usage and classes that are lendable to the south-east region of Romania, as well as the pollution sources coming from agriculture, to know: the fertilizers, the phytosanitary products, the residues originating in animal farming and the irrigations. The second part of the work presents the objectives and measurements that impose regarding the reduction of the pollution of the soil. In this sense they must put the accent on an alternative agriculture, which contains: the rotation of cultures, the usage of pesticides with a reduced persistence, the recycling of waste resulting from collective farms and a lasting agriculture which represents a long-term action, by which one continues to exceed the problems and the restrictions of conventional agriculture. In the final one presents the proposal for a Directive concerning the frame of protection of the soil. The four pillars of the policy of the European Union concerning the protection of the soil are: a better conscience, the research, the integration of the aspects of the protection of the soil and the legislation.
A STUDY OF THE POLLUTING FACTORS OF THE AQUATIC ENVIRONMENT AND THEIR INFLUENCE UPON FISHES<br/> ÉTUDE DES FACTEURS POLLUANTS DE L’ENVIRONNEMENT AQUATIQUE ET LEUR INFLUENCE SUR LES POISSONS
ELPIDA PALTENEA(1*), NECULAI PATRICHE(1), MARGARETA ZARA(2), ELENA MOCANU(1), AIDA VASILE(2)
The level and distribution of heavy metals (Cu, Pb, Zn, Cd) and organochlorine pesticides, hexachlorocyclohexane (HCH) isomers and sum DDT, were investigated in water, sediments and fishes samples collected from Danube River and Research Farm Brateº, ICDEAPA Galaþi. Determinations were effectuated trough spectrophotometer with atomic absorption for heavy metals and organochlorine pesticides were determined trough gas-chromatography method AOAC 970.52. In conformity with effectuated studies, all samples showed a relatively low degree of contamination with heavy metals and organochlorine pesticides. Concentration of heavy metals from Danube River is higher than the samples concentration from Brates Farm. The highest values are registered in the samples of Danube water (Pb 124 ng.L-1, Cd 232 ng.L-1) in comparison with the values of samples from water collected from Brateº Farm (Pb 30.6 ng.L-1). The level of heavy metals bioaccumulation in fish is similarly in the samples from Danube and Brateº Farm. From the investigated organochlorine compounds were identified α-HCH and γ-HCH in Danube water samples. The level of organochlorine pesticides from fish is higher in the samples collected from Brateº Farm than in the samples from Danube River, especially from the point of view of DDT (H. molitrix H2+ 93 μg.kg-1, C. carpio C2+ 121 μg.kg-1, A. nobilis A3+ 96 μg.kg-1). All investigated samples contained heavy metals and organochlorine pesticides levels below the official Romanian norms.
PIG SLAUGHTERING TECHNOLOGY BY SCALDING – SKINNING. TECHNOLOGICAL MODIFICATIONS WITH IMPLICATIONS IN MITIGATION OF THE ENVIRONMENTAL POLLUTION<br/> TECHNOLOGIE D’ABATTAGE PORCIN PAR ÉCHAUDAGE – ÉCORCHEMENT. MODIFICATIONS TEHNOLOGIQUES AUX IMPLICATIONS DA
IULIAN SUCEVEANU(1*), MIRELA SUCEVEANU(2), DOMNICA CIOBANU(2)
The purpose of our study is to bring into focus certain methods by means of which we try to organize the technological pig slaughtering process that will lead us to a smaller percent of slaughterhouse’s inedible products. We searched for the optimal variant of processing, the technological parameters that let us an efficient scalding and the removal of skin from the carcass by skinning at the mechanical skinning, resulting a new technology combining elements by the scalding and skinning method. The new method of pig scalding-skinning is characterized by: • The decrease of the steam consuming by lowering the scalding temperature from 65 °C up to 62.5 °C; • The decrease of methane consuming at singeing with 30% by lowering the number of air nozzles and of building-up rise time during the singeing process; • The decrease by 10% of the necessary refrigeration agent consuming during the refrigeration process of carcasses and the decrease up to 15% of refrigeration time carcasses; • The decrease up to 50% of skin time processing in comparison to the classical scalding technology; • The increase up to 4% of the recovery percentage of lard after removal from carcass and the result is edible lard.
STUDY OF THE PROPERTIES OF THE EMULSIONS BASED ON PEA PROTEIN ISOLATE ENZYMATICALLY MODIFIED WITH MICROBIAL TRANSGLUTAMINASE<br/> L’ÉTUDE DES PROPRIÉTÉS DES ÉMULSIONS À BASE D’ISOLAT PROTÉIQUE DE POIS MODIFIÉ ENZYMATIQUEMENT AVEC TRANSGLUTAMINASE MI
AURELIA IONESCU(1), MARGARETA ZARA(1*), IULIANA APRODU(1), AIDA VASILE(1), GABRIELA GURĂU(2)
The oil-in-water emulsions based on pea protein isolate enzymatically modified with bacterial transglutaminase (MTGase) were obtained and characterized by assessing their functional and rheological properties. Our results showed that during shearing flow process, the protein emulsions behave like non-Newtonian fluids. The apparent viscosity decreased by increasing the shearing rate in the range 0.1667 – 148.5 s-1. A direct correlation was found between the rheological characteristics of the studied emulsions and the level of added MTGase, temperature and enzyme reaction time. The present study was aimed by the evaluation of the effect of MTGase interaction with pea proteins on functional and rheological characteristics of their emulsions. In order to find out the optimal parameters to be used for obtaining emulsions with enhanced functional and rheological properties, different levels of added enzyme, reaction time and temperature of reaction were tested.
MODEL OF PREDICTION OF THE RHEOLOGICAL BEHAVIOR FOR COMPLEX EMULSIONS OF THE RAPESEED OIL WITH VARIABLE CONTENTS OF FREE FATTY ACIDS AND WATER<br/> MODELE DE PREDICTION DU COMPORTEMENT RHEOLOGIQUE POUR DES EMULSIONS COMPLEXES DE L’HUILE DE COLZA AVEC UN
I. VINTILA(1*), A. GAVRUS(2), P. ALEXE (1), C. VIZIREANU(1)
The present paper research has realized the validation of a mathematical model applied for the prediction of rheological behavior of the complex emulsions type W/O water 30%-crude, refined rapeseed oil 70%. The rheological behavior were investigated for the emulsions realized with two types of industrial oils: C1 and C2 - crude and refined rapeseed oil with different physical-chemical composition: 892 ppm phospholipids content, 1.09 FFA-index, 0.18% moisture, impurities insoluble in solvents 0.12% for C1; 50 ppm phospholipids content, 0.10 FFA-index and 0.020% moisture for C2. The mathematical model for the emulsions rheological behavior prediction was correlated with the composition of the complex emulsions W/O with crude and refined rapeseed oils. The parameters of the mathematical model were identify by the inverse analysis method based on the experimental rheological data values and were realized the validation of the theoretical mathematical model.
INFLUENCE OF VARIOUS THERMAL TREATMENTS OVER VITAMIN C CONCENTRATION IN LEMONS
ANDREI I. SIMION(*), LĂCRĂMIOARA RUSU, IOANA ŞTEFĂNESCU, LUCIAN GAVRILĂ
The chemical instability of vitamin C acid is due to the fact that it is a strong reducing agent and can be deactivated by a wide range of oxidizing agents. In food industry the use of various thermal processes has, in the most cases, a negative impact over the preservation of vitamin C content alongside raw materials conversion into the final products. A comparative study about the variations of vitamin C concentrations in lemons is presented in this paper, variations being produced by the uses of low, medium and respectively high temperature treatments.