Hydrolysis of lactose from cheese whey using a reactor with beta-galactosidase enzyme immobilized on a commercial UF membrane

In this study, ß-galactosidase enzyme from Kluyveromyces fragilis was immobilised on a commercial polyethersulfone membrane surface, 10 kDa cut-off. An integrated process, concerning the simultaneous hydrolysis–ultrafiltration of whey lactose was studied and working conditions have been fixed at 55°C and pH 6.9, the same conditions that are used for the industrial process of protein concentration. For the immobilisation, best results were obtained using 5% (v/v) of glutaraldehyde solution and 0.03 M galactose; the total activity recovery coefficient (TARC) was 44.2%. The amount of immobilised enzyme was 12.49 mg with a total activity of 86.3 LAU at 37°C, using 5% (w/v) lactose solution in phosphate buffer (100 mM pH 6.9). The stability of the immobilised enzyme was approximately 585 fold higher in comparison with the stability of free enzyme. Multipoint covalent immobilisation improves the stability of the enzyme, thereby enhancing the decision to use the membrane as a filtering element and support for the enzyme immobilisation.Fil: Regenhardt, Silvina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); ArgentinaFil: Mammarella, Enrique José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); ArgentinaFil: Rubiolo, Amelia Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); Argentin

Vinculación y transferencia de conocimientos en la Universidad Nacional del Litoral

En general, las Universidades Nacionales Argentinas, luego de recuperar su autonomía en 1985, debido a un contexto totalmente desfavorable respecto a la situación del Estado Nacional, comenzaron en los años 90s a llevar adelante políticas de vinculación con su entorno. Acompañando a las Universidades, las actividades de vinculación tecnológica y transferencia de conocimientos ocuparon el centro de las políticas públicas hacia sector socio-productivo, y se llevaron adelante diversos mecanismos promocionales que tuvieron un fuerte impacto en la generalización de nuevas modalidades.En este contexto, la Universidad Nacional del Litoral (UNL) ha venido instrumentado, desde hace más de tres décadas, políticas concretas de promoción de la innovación y transferencia de los resultado de la investigación, las cuales tienen por objetivo asegurar su apropiación por parte del tejido económico y social. Esta situación propone con mayor fuerza, la necesidad de generar renovados procesos de vinculación entre la Universidad y las organizaciones del medio socio-productivo y gubernamental.El objeto del presente trabajo es analizar la política de vinculación de Universidad Nacional del Litoral, con el fin estudiar el modelo de transferencia aplicado en la región Litoral-Centro del país, como así también dimensionar al grado de alcance que tiene esta política en la región.

Whey protein hydrolysis with free and immobilized Alcalase®: effects of operating parameters on the modulation of peptide profiles obtained

In this work, the effects of operating parameters on the modulation of peptide profiles obtained during enzymatic hydrolysis of whey protein concentrates (WPC) with a commercial enzyme (Alcalase 2.4L AF) were analyzed. Hydrolyzates of WPC were obtained working with free and immobilized enzyme and evaluating different operating conditions (initial substrate concentrations, time, temperature and pH). Characteristics of hydrolyzates obtained were evaluated by the hydrolysis degree obtained (DH) and the peptide profile by RP-HPLC. Moreover, a quantitative descriptive sensory analysis was performed to compare different preparations of commercial desserts prepared using as ingredients milk, WPC and WPC hydrolyzates. The DH values increased very quickly during the first 10 min. followed by a slow increase up to 25 min. For the range of conditions tested, we proposed to operate at temperatures close to 50˚C, pH between 8 and 9 and initial substrate concentration from 7% as good reactions conditions. Finally, whey protein hydrolyzates obtained with Alcalase showed very interesting sensorial characteristics to be incorporated in desserts commercial preparations.Fil: Fenoglio, Cecilia Lorena. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vierling, Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Manzo, Ricardo Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Ceruti, Roberto Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Sihufe, Guillermo Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Mammarella, Enrique José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin

Hydrolysis of lactose: estimation of kinetic parameters using Artificial Neural Networks

The analysis of any kinetic process involves the development of a mathematical model with predictive purposes. Generally, those models have characteristic parameters that should be estimated experimentally. A typical example is Michaelis-Menten model for enzymatic hydrolysis. Even though conventional kinetic models are very useful, they are only valid under certain experimental conditions. Besides, frequently large standard errors of estimated parameters are found due to the error of experimental determinations and/or insufficient number of assays. In this work, we developed an artificial neural network (ANN) to predict the performance of enzyme reactors at various operational conditions. The net was trained with experimental data obtained under different hydrolysis conditions of lactose solutions or cheese whey and different initial concentrations of enzymes or substrates. In all the experiments, commercial beta-galactosidase either free or immobilized in a chitosan support was used. The neural network developed in this study had an average absolute relative error of less than 5% even using few experimental data, which suggests that this tool provides an accurate prediction method for lactose hydrolysisFil: Cuellas, Anahí V.. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Área Ingeniería en Alimentos; ArgentinaFil: Oddone, Sebastián. Universidad Argentina de la Empresa. Facultad de Ingeniería y Ciencias Exactas; ArgentinaFil: Mammarella, Enrique José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); ArgentinaFil: Rubiolo, Amelia Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); Argentin

Crosslinking kinetics of cation-hydrocolloid gels

The gel formation of hydrocolloid (sodium alginate and kappa-carrageenan) is the result of the molecule aggregation in presence of an effective cation. The gelling process was considered as a process of diffusion–reaction between the effective cation and the hydrocolloid to produce a porous solid structure. A simple mathematical model for predicting the reaction interface position in alginate or alginate-carrageenan gelation was developed. The model represents appropriately the physicochemical phenomenon and allows to determine the time for complete crosslinking of the hydrocolloid and the amount of incorporated ions.Fil: Mammarella, Enrique José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Rubiolo, Amelia Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin

Study of the Deactivation of ß-galactosidase Entrapped in Alginate-carrageenan Gels

The stability of ß-galactosidase entrapped in Ca-alginate–K-k-carrageenan gels under operation conditions was studied. The thermal deactivation of the immobilised enzyme and the biocatalyst protein loss due to gel swelling were taken into account in the mass balance of the enzymatic reaction rate expression. Time-temperature effect was the most important factor in the biocatalyst deactivation reaction. However, results showed that the enzyme entrapped in gels was partially lost by gel swelling, which was a source of error in predicting results in continuous processes. The enzyme loss determined in this work showed a non-linear behaviour and it depended on mixing conditions of the reactor. Values of protein loss were used in the modelling of a fixed-bed reactor with similar flow conditions to reduce the error in predicting the operation conditions to maintain a constant conversion. For reaction conditions similar to those analysed in this work, the ß-galactosidase was well entrapped in alginate-carrageenan matrices.Fil: Mammarella, Enrique José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Rubiolo, Amelia Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin

Effect of biocatalyst swelling on the operation of packed-bed immobilized enzyme bioreactor

A general mathematical model was developed for predicting the performance and simulation of a packed-bed immobilized enzyme reactor performing a reaction that follows Michaelis–Menten kinetics with competitive product inhibition. The performance of a packed-bed immobilized enzyme reactor was analyzed taking into account the effect of bed swelling on various diffusional phenomena such as axial dispersion, internal and external mass transfer limitations. The numerical solutions were compared with experimental data obtained for a packed-bed reactor operating with β-galactosidase entrapped in Ca-alginate-K-κ-carrageenan gels for lactose hydrolysis.Fil: Mammarella, Enrique José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Rubiolo, Amelia Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin

Predicting the packed-bed reactor performance with immobilized microbial lactase

A mathematical model for several working conditions was numerically solved to study a fixed bed reactor with a biocatalyst. The effect of bed swelling, mass transfer limitations, axial dispersion, residence times and inlet lactose concentration were studied. A Michaelis–Menten kinetics with competitive product inhibition was used to represent the enzymatic reaction of the lactose hydrolysis by the b-galactosidase. Lactose conversion was used to determine the appropriate conditions for the immobilized enzyme reactor. The model predicted the experimental data with errors less than 2.5%.Fil: Mammarella, Enrique José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Rubiolo, Amelia Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin

Prediction of the fixed-bed reactor behaviour using dispersion and plug-flow models with different kinetics for immobilised enzyme

The behaviour of fixed-bed reactors, which have an immobilised enzyme on the packing surface, was studied considering steady-state conditions and external mass transfer resistance in the fluid around catalyst spherical particles. Solutions were obtained by integration of the plug-flow model equation and by the orthogonal collocation method of the second order differential equation of the axial dispersion flow model. Both models were analysed for lactose hydrolysis with β-galactosidase immobilised on chitosan using different kinetic reaction mechanisms after determining the specific parameters. The calculated results show the importance of the hydrodynamic and kinetic reaction parameters for error reduction in the prediction of the experimental behaviour.Fil: Carrara, Carlos Roberto. Universidad Nacional del Litoral; ArgentinaFil: Mammarella, Enrique José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Rubiolo, Amelia Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin