Recursos de colección

Repositorio Hipermedial UNR - Repositorio Hipermedial de la Universidad Nacional de Rosario (6.314 recursos)

El Repositorio Hipermedial UNR es un repositorio académico abierto creado para archivar, preservar y distribuir digitalmente en variados formatos tanto materiales de enseñanza y aprendizaje (objetos de aprendizaje) como la producción científica de Investigación y Desarrollo (I+D) de los profesores, profesional es e investigadores de la UNR.

Mostrando recursos 1 - 14 de 14

  1. Desarrollo de quesos frescos funcionales y saludables a partir de leche bovina

    Pavón, Yanina; Galante, Micaela; Boeris, Valeria; Risso, Patricia Hilda; Lazzaroni, Sandra; Rozycki, Sergio
    La industria alimentaria enfrenta el desafío de desarrollar nuevos alimentos funcionales que mejoren el estado nutricional general de la población, con la finalidad de impedir la incidencia de enfermedades surgidas como consecuencia de deficiencias nutricionales y de la ingesta excesiva de con la dieta de compuestos tales como el colesterol. El objetivo de este trabajo fue elaborar un queso fresco tipo Cuartirolo, fortificado con zincy con contenido de colesterol reducido, y comprarlo con un queso tradicional. Adicionalmente, se elaboraron quesos testigos.

  2. Structural characterization of protein isolates obtained from chia (Salvia hispanica L.) seeds

    López, Débora Natalia; Ingrassia, Romina; Busti, Pablo; Bonino, Julia; Delgado, Juan Francisco; Wagner, Jorge; Boeris, Valeria; Spelzini, Darío
    Chia protein isolates (CPI) were obtained through isoelectric precipitation under two different conditions in order to compare their structural properties. Extraction was carried out at pH 10 or 12, whereas precipitation pH was fixed at 4.5. Samples were named as CPI10 or CPI12, according to their extraction pH (10 or 12, respectively). The recovery of chia proteins was higher when the extraction was carried out at pH 12 (17% for CPI12 and 13% for CPI10); however, CPI12 protein content (775g/kg) was slightly lower than CPI10 protein content (782g/kg). Both samples showed similar SDS-PAGE pattern. Protein dispersions of both isolates led...

  3. Amaranth, quinoa and chia protein isolates: physicochemical and structural properties

    López, Débora Natalia; Galante, Micaela; Robson, María; Boeris, Valeria; Spelzini, Darío
    An increasing use of vegetable protein is required to support the production of protein-rich foods which can replace animal proteins in the human diet. Amaranth, chia and quinoa seeds contain proteins which have biological and functional properties that provide nutritional benefits due to their reasonably well-balanced aminoacid content. This review analyses these vegetable proteins and focuses on recent research on protein classification and isolation as well as structural characterization by means of fluorescence spectroscopy, surface hydrophobicity and differential scanning calorimetry. Isolation procedures have a profound influence on the structural properties of the proteins and, therefore, on their in vitro digestibility....

  4. A combined experimental and molecular simulation study of factors influencing interaction of quinoa proteins–carrageenan

    Montellano Durán, Natalia; Spelzini, Darío; Wayllace, Natanel; Boeris, Valeria; Baroso da Silva, Fernando
    The interaction between quinoa proteins isolate (QP isolate) and the negatively charged polysaccharide ι-Carragennan (Carr) as a function of pH was studied. Experimental measurements as turbidity, hydrophobic surface, ζ-potential, and hydrodynamic size were carried out. Associative interaction between QP and Carr was found in the pH range between 1 and 2.9. When both molecules are negatively charged (pH > 5,5), a pure Coulombic repulsion regime is observed and the self-association of QP due to the Carr exclusion is proposed. In the intermediate pH range, the experimental data suggests that the charge regulation mechanism can overcome the electrostatic repulsion that may...

  5. Milk protein suspensions enriched with three essential minerals: Physicochemical characterization and aggregation induced by a novel enzymatic pool

    Lombardi, Julia; Spelzini, Darío; Folmer Côrrea, Ana Paula; Brandelli, Adriano; Risso, Patricia Hilda; Boeris, Valeria
    Structural changes of casein micelles and their aggregation induced by a novel enzymatic pool isolatedfrom Bacillus spp. in the presence of calcium, magnesium or zinc were investigated. The effect of cationson milk protein structure was studied using fluorescence and dynamic light scattering. In the presenceof cations, milk protein structure rearrangements and larger casein micelle size were observed. Theinteraction of milk proteins with zinc appears to be of a different nature than that with calcium ormagnesium. Under the experimental conditions assayed, the affinity of each cation for some groupspresent in milk proteins seems to play an important role, besides electrostatic interaction....

  6. Caseínas em leite de ovelha

    Nespolo, Cássia Regina; Risso, Patricia Hilda
    O leite de ovelha possui um teor proteico mais elevado que o leite bovino, o que faz com que essa matéria-prima tenha um bom rendimento industrial. As principais proteínas do leite ovino são as caseínas e os tipos são os mesmos que no leite de vaca, porém as características estruturais demonstram variações em relação às de origem bovina. Isso afeta a estabilidade coloidal do leite ovino, levando a um menor tempo para coagulação e tornando-o menos estável aos tratamentos térmicos. Desta forma, deve-se considerar a dificuldade na produção de derivados lácteos ovinos processados a temperaturas elevadas, alterando principalmente a aparência...

  7. Physicochemical study of mixed systems composed by bovine caseinate and the galactomannan from Gleditsia amorphoides

    López, Débora; Galante, Micaela; Álvarez, Estela M.; Risso, Patricia Hilda; Boeris, Valeria
    Model systemsformed by sodium caseinate (NaCAS) and espina corona gum (ECG) were studied. Therewas no evidence of attractive interactions between NaCAS and ECG macromolecules.Aqueous mixtures of NaCAS and ECG phase-separate segregatively over a wide rangeof concentrations. According to the images obtained by confocal laser scanning microscopy,NaCAS particles form larger protein aggregates when ECG is present in the system.An increase in the hydrodynamic diameter of NaCAS particles, as a result of ECGaddition, was also observed by light scattering in diluted systems.A depletion?flocculation phenomenon, in which ECG is excluded from NaCAS surface,is proposed to occur in the concentrated mixed systems, resulting in...

  8. Acid-induced Aggregation and Gelation of Sodium Caseinate-Guar Gum Mixtures

    Hidalgo, María Eugenia; Fontana, Manuel; Armendariz, Mirta; Riquelme, Bibiana; Wagner, Jorge Ricardo; Risso, Patricia Hilda
    The aim of this work was to study the formation of bovine sodium caseinate (NaCAS) acid gels induced by addition of glucono-delta-lactone (GDL) in the presence of guar gum (GG). At low biopolymer’s concentrations, a one-phase system was observed, whereas at higher mixture concentrations two-phase systems were formed. Aggregation (at low NaCAS concentrations) and gelation (at high NaCAS concentrations) processes were analyzed through the use of full and fractional factorial experiment designs, using turbidimetric and rheological techniques. Finally, the gel images were obtained by confocal laser scanning microscopy and the images were analyzed. Results showed that at low NaCAS concentrations,...

  9. Biological and physicochemical properties of bovine sodium caseinate hydrolysates obtained by a bacterial protease preparation

    Hidalgo, María Eugenia; Folmer Côrrea, Ana Paula; Mancilla Canales, Manuel; Daroit, Daniel; Brandelli, Adriano; Risso, Patricia Hilda
    In this work, we aimed at the production of bovine sodium caseinate (NaCAS) hydrolysates by means of an extracellular protease from Bacillus sp. P7. Mass spectrometry was carried out to evaluate peptide mass distribution and identified sequences of peptides with a signal/noise ratio higher than 10. Antioxidant and antimicrobial properties of hydrolysates were evaluated. An acid-induced aggregation process of the hydrolysates and their corresponding mixtures with NaCAS were also analyzed. The results showed that the enzymatic hydrolysis produced peptides, mostly lower than 3 kDa, with different bioactivities depending on the time of hydrolysis (ti). These hydrolysates lost their ability to...

  10. Application of a digital image procedure to evaluate microstructure of caseinate and soy protein acid gels

    Ingrassia, Romina; Costa, Juan Pablo; Hidalgo, María Eugenia; Mancilla Canales, Manuel; Castellini, Horacio; Riquelme, Bibiana; Risso, Patricia Hilda
    Acid gelation of proteins is commonly used in the food industry and it can be induced by the addition of glucono-delta-lactone (GDL). The aim of this work was to use textural analysis of images in order to assess possible changes in the microstructure of bovine sodium caseinate (NaCAS) and soy protein isolate (SPI) acid gels. The gelation rate of NaCAS related to the amount of GDL was evaluated. Also, the effect of the presence of NaCAS hydrolyzates obtained at different hydrolysis times by the enzyme of Bacillus sp. P7 was studied. Finally, SPI acid gels were evaluated in the presence...

  11. Effect of cholesterol-reduced and zinc fortification treatments on physicochemical, functional, textural, microstructural and sensory properties of soft cheese

    Galante, Micaela; Pavón, Yanina; Lazzaroni, Sandra; Soazo, Marina; Costa, Silvia; Boeris, Valeria; Risso, Patricia Hilda; Rozycki, Sergio
    The aim of this study was to produce and evaluate a soft cheese fortified with zinc and with cholesterol-reduced content. To meet this objective, a cream base was prepared, from which cholesterol was removed using b-cyclodextrin as extracting agent. Then, cholesterol-reduced content cheese with and without the addition of zinc salts (ZnSO4 or ZnCl2) was produced. Additionally, a cheese without any treatment was prepared. Furthermore, physicochemical, textural, functional, microstructural and sensory determinations were performed. As a result, 87–94% zinc-fortified and 93% cholesterol-reduced cheese samples were obtained, which had similar sensorial characteristics to the cheese without treatment.

  12. Effect of cholesterol-reduced and zinc fortification treatments on physicochemical, functional, textural, microstructural and sensory properties of soft cheese

    Galante, Micaela; Pavón, Yanina; Lazzaroni, Sandra; Soazo, Marina; Costa, Silvia; Boeris, Valeria; Risso, Patricia Hilda; Rozycki, Sergio
    The aim of this study was to produce and evaluate a soft cheese fortified with zinc and with cholesterol-reduced content. To meet this objective, a cream base was prepared, from which cholesterol was removed using b-cyclodextrin as extracting agent. Then, cholesterol-reduced content cheese with and without the addition of zinc salts (ZnSO4 or ZnCl2) was produced. Additionally, a cheese without any treatment was prepared. Furthermore, physicochemical, textural, functional, microstructural and sensory determinations were performed. As a result, 87–94% zinc-fortified and 93% cholesterol-reduced cheese samples were obtained, which had similar sensorial characteristics to the cheese without treatment.

  13. Effect of Xanthan Gum on the Rheological Behavior and Microstructure of Sodium Caseinate Acid Gels

    Hidalgo, María Eugenia; Armendariz, Mirta; Wagner, Jorge Ricardo; Risso, Patricia Hilda
    The aim of this work was to study the effect of xanthan gum (XG) on the gelation process of bovine sodium caseinate (NaCAS) induced by acidification with glucono-delta-lactone (GDL) and on the mixed acid gel microstructure. Before GDL addition, segregative phase separation was observed in all the NaCAS-XG mixtures evaluated. The gelation process was analyzed by using a fractional factorial experimental design. The images of the microstructure of the mixed acid gels were obtained by conventional optical microscopy and the mean diameter of the interstices was determined. Both the elastic character and the microstructure of the gels depended on the concentrations...

  14. Effect of Xanthan Gum on the Rheological Behavior and Microstructure of Sodium Caseinate Acid Gels

    Hidalgo, María Eugenia; Armendariz, Mirta; Wagner, Jorge Ricardo; Risso, Patricia Hilda
    The aim of this work was to study the effect of xanthan gum (XG) on the gelation process of bovine sodium caseinate (NaCAS) induced by acidification with glucono-delta-lactone (GDL) and on the mixed acid gel microstructure. Before GDL addition, segregative phase separation was observed in all the NaCAS-XG mixtures evaluated. The gelation process was analyzed by using a fractional factorial experimental design. The images of the microstructure of the mixed acid gels were obtained by conventional optical microscopy and the mean diameter of the interstices was determined. Both the elastic character and the microstructure of the gels depended on the concentrations...

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