Effect of isolation conditions on structural properties and surface behavior of soy-whey proteins

In this study, the impact of isolation conditions on structural and surface properties at the air/water interface of soy-whey proteins (SWP) was assessed. SWP were obtained by precipitation of soy-whey (at pH 4.5 or 8.0) with acetone or ammonium sulfate. Despite the fact that all SWP samples exhibited similar electrophoretic patterns, they showed different protein content (from 54.2 to 98.2% w/w). When precipitation was performed at pH 4.5, SWP samples evidenced a decrease of protein solubility (SP) and thermal stability, while the precipitation with acetone promoted the enrichment in polysaccharides and minerals. For all samples, intrinsic fluorescence, surface hydrophobicity and Fourier transform infrared (FTIR) studies revealed structural changes correlated to protein unfolding and aggregation processes. However, the surface behavior can be predicted from these studies mainly due to differences in surface hydrophobicity and the differential contribution of insoluble aggregates. The heating of SWP samples enhanced the surface activity, regardless of the pH of the raw material and the isolation method. These results can be useful as a reference research and as a starting point for industrial exploitation of proteins from soy wastewater.Fil: Ingrassia, Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Sobral, Pablo Antonio. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; ArgentinaFil: Risso, Patricia Hilda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Palazolo, Gonzalo Gastón. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Investigación en Funcionalidad y Tecnología de Alimentos; ArgentinaFil: Wagner, Jorge Ricardo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Investigación en Funcionalidad y Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Microstructural and textural properties of rennet-induced milk protein gel: Effect of guar gum

The knowledge of the effect of polysaccharide addition on the textural properties of milk protein gels is important for foodstuff engineering design. Therefore, the microstructure, texture, and water-holding capacity of rennet-induced milk protein gel with and without the addition of different concentrations of guar gum (GG) were determined. It was found that the presence of GG changed the microstructure of rennet-induced milk gel. The addition of a GG concentration higher than 0.075% w/v led to a discontinuous protein network. Changes in the structure of the gel samples are reflected in the texture perception and their capability of water retention. When a limit GG concentration of 0.15% w/v was exceeded, a very weak gel sample was obtained. The results demonstrated that different milk protein gel microstructures can be created by the addition of different concentrations of GG.Fil: Galante, Micaela. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmaceuticas. Departamento de Química y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Boeris, Valeria. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmaceuticas. Departamento de Química y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires"; ArgentinaFil: Alvarez, Estela Mari. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmaceuticas. Departamento de Química y Física; ArgentinaFil: Risso, Patricia Hilda. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmaceuticas. Departamento de Química y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias; Argentin

Microstructural and textural characteristics of soy protein isolate and tara gum cold-set gels

Soy protein isolates (SPI) are capable of forming cold-set gels. This techno-functional property can be affected by the presence of tara gum (TG). Under certain conditions, these SPI/TG systems may also form water-in-water (W/W) emulsions. The aim of this study was to evaluate acid gels formed from soy protein isolates (SPI) and tara gum (TG) aqueous mixtures, and to find the conditions in which the W/W emulsions of SPI droplets dispersed in a TG continuous phase can be stabilized by SPI gelation as a strategy to prevent emulsion destabilization. Cold-set gels of SPI 0.3 g/L at different TG concentrations (0–0.05 g/L) showed different microstructures, a consequence of a different balance between gelation and segregative phase separation processes. SPI gels showed a homogenous and compact microstructure. When TG was present at 0.01 g/L and 0.02 g/L, the protein network was less interconnected, showing coarse-stranded and bicontinuous gels, respectively. At TG > 0.03 g/L, stable W/W emulsions were formed, revealing an abrupt decrease in gel firmness, a significant loss of fracture capacity, and a decrease in the water holding capacity. These findings may be used as a starting point for the application of these gelled systems as thickeners, texture modifiers, and coating materials for delivery of bioactive compounds.Fil: Ingrassia, Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias; ArgentinaFil: Bea, Lucas Leonardo. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: Hidalgo, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias; ArgentinaFil: Risso, Patricia Hilda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias; Argentin

Heat treatments of defatted soy flour: impact on protein structure, aggregation, and cold-set gelation properties

This study reveals that mild heat treatments of defatted soy flour promote Maillard reaction and modify its protein techno-functional properties such as solubility, aggregation, and cold-set gelation. Glycation was promoted by treatments of defatted soy flour (DSF) at 60 °C for 12, 24, and 48 h, with and without relative humidity control (RHC and WRHC, respectively) at 79%. All samples presented a significant increase of glycation extent (GE), reaching the highest value after 48 h at RHC. Despite all samples presented a similar protein denaturation degree, the increase in GE was accompanied by a decrease of antitryptic activity. Protein solubility (PS) of DSF remained constant for treated samples WRHC. However, PS decreased progressively with the treatment time at RHC. SDS-PAGE of soluble proteins revealed a positive relation between band intensities and PS. Despite sample dispersions showed a protein particle size increment with treatment time, further aggregation after heat-treatments at 100 °C produced a similar protein size distribution among samples. Rheological and microstructural studies of cold-set gels of samples obtained WRHC revealed no changes in the maximum elastic modulus (G’max) and a slight increase of its pore sizes. However, samples obtained with RHC showed cold-set gels with a progressive G’max decrease with the treatment time, which could be related to a coarser gel microstructure. In the more extreme condition, the sample obtained after 48 h at RHC showed a total loss of gelation capability. These results can be used to address the development of new tofu-like food products with different rheological properties.Fil: Ingrassia, Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias; ArgentinaFil: Palazolo, Gonzalo Gastón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Investigación en Funcionalidad y Tecnología de Alimentos; ArgentinaFil: Wagner, Jorge Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Investigación en Funcionalidad y Tecnología de Alimentos; ArgentinaFil: Risso, Patricia Hilda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias; Argentin

Microstructural evolution of a heterogeneous austenitic stainless steel processed by Equal Channel Angular Sheet Extrusion (ECASE)

Peer ReviewedPostprint (author's final draft

Physical-mathematical model to predict the kinetic coagulation process by clotting activity of bacterial endopeptidases

A physical-mathematical model was used to evaluate the capability of an enzymatic pool of Bacillus sp. P7 (isolated from Piaractus mesopotamicus) to promote the bovine casein micelles coagulation. Experiments were designed to assess the effects of temperature, pH, and enzyme activity/mass of substrate ratio on the kinetic parameters of the coagulation process and the microstructure of the obtained clots. Descriptive and predictive equations indicate that the temperature and the pH modified these parameters significantly. In optimal conditions, the clot’s mean pore size was 3.6 times smaller using chymosin. On the other hand, rheological measurements evidence a moderate elasticity of clot, which indicates the usefulness of P7 protease preparation as a clotting agent in spreadable or soft cheese manufacture. Also, the hydrolysis products, which are in the whey after casein micelles coagulation, demonstrated antioxidant activities. Equations to model and predict the process kinetics were combined with rheological and microstructure analyses of the obtained clots, and whey bioactivities were evaluated. Nevertheless, the use of P7PP requires further investigation concerning the stability of the enzyme preparation during storage, its performance, and how these variables could be related to the proposed models.Fil: Mancilla Canales, Manuel Arturo. Grupo de Física Biomédica. Instituto de Física Rosario (CONICET-UNR); Argentina.Fil: Riquelme, Bibiana Doris. Grupo de Física Biomédica. Instituto de Física Rosario (CONICET-UNR); Argentina.Fil: Mancilla Canales, Manuel Arturo. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina.Fil: Riquelme, Bibiana Doris. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina.Fil: Risso, Patricia Hilda. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina.Fil: Folmer Côrrea, Ana Paula. Universidade Federal de Rio Grande do Sul. Instituto de Ciência e Tecnologia de Alimentos; Brasil.Fil: Brandelli, Adriano. Universidade Federal de Rio Grande do Sul. Instituto de Ciência e Tecnologia de Alimentos; Brasil.Fil: Risso, Patricia Hilda. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias; Argentina

Effects of Cholesterol Extraction Process and Fat and Whey Protein Additions on Ice Cream Mixes

The aim of this work was to evaluate the cholesterol extraction process in ice cream mixes (ICMs) by using β-cyclodextrin (βCD) and to analyze the effect of this extraction on the ICM rheological, stability, and sensory characteristics. The effects of fat and whey protein (WP) additions on ICM stability were also evaluated. The maximum percentage obtained for cholesterol extraction was 93.6%. The flow curves indicated that ICM showed a thixotropic behavior before and after cholesterol extraction, which was enhanced when the fat content and/or percentage of βCD increased. The stability of ICM with cholesterol-reduced content (RCho-ICM) was influenced by the fat content and/or the presence of WP. The RCho-ICM with the highest fat and/or WP addition showed less tendency to melt and had the smallest amount of accumulated molten liquid. These latter ICMs presented the slowest melting rates. Also, RCho-ICMs proved to be more stable than ICMs. RCho-ICM samples obtained with a ratio of βCD/fat content of 1% w/w were evaluated by a trained sensory panel. In addition, an acceptability test of the sample with better sensory attributes was conducted.Fil: Hidalgo, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: Bordino, Juliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: Acciarri, Giuliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: Fernández, Juan Manuel. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; ArgentinaFil: Rozycki, Sergio Darío. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; ArgentinaFil: Risso, Patricia Hilda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; Argentin

Application of an enzymatic extract from Aspergillus niger as coagulant for cheddar cheese manufacture

Q2 según Scopus a la fecha de publicaciónThe coagulation of milk by a serin protease from Aspergillus niger NRRL3 was studied by rheology. Cheddar-type cheese was manufactured using 3.5% (v/v) of fungal enzymatic extract and fermentation-produced chymosin was used as control coagulant. Full composition and ripening of both kinds of Cheddar cheese were studied. Differences in the proteolysis of caseins, not only during cheese manufacture but also during ripening, affected cheese composition, texture and peptide profile. Microbial development during ripening was not affected by the coagulant used.Fil: Lombardi, Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Química y Física. Área Fisicoquímica; ArgentinaFil: Ciocia, Felicia. University College Cork; IrlandaFil: Uniacke Lowe, Thérèse. University College Cork; IrlandaFil: Boeris, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Química y Física. Área Fisicoquímica; Argentina. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Facultad de Química e Ingeniería-Rosario; ArgentinaFil: Risso, Patricia Hilda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Química y Física. Área Fisicoquímica; ArgentinaFil: McSweeney, Paul L. H.. University College Cork; Irland