Emulsifiers: effects on quality of Fibre-Enriched wheat bread

Resistant starch (RS) is a nutritional ingredient commonly used in bread products as dietary fibre (DF). This ingredient presents similar physiological functions than those imparted by DF, promoting beneficial effects such as the reduction of cholesterol and/or glucose levels on blood. Quality improvement of bread containing RS, with an optimized combination of emulsifiers, will be useful in the development of new and healthy bakery products. The objective of this research was to analyse the effects of different emulsifiers on several quality parameters of dough and bread prepared with wheat flour partially substituted with resistant starch as a dietary fibre. A blend of wheat flour/ maize-resistant starch (MRS; 87.5:12.5) with sodium chloride, ascorbic acid, α-amylase, compressed yeast and water was utilized. Emulsifiers were incorporated to formulations in different levels according to a simplex centroid design. The viscoelastic, textural and extensional properties of dough were analysed. Bread quality was evaluated throughout the gelatinization and retrogradation of starch, specific volume of loaves, and texture and firmness of bread crumb. The incorporation of 12.5% (w/w) of MRS to wheat flour caused an increase of 5% in water absorption. Stability decreases markedly (from 9.9 to 2.2 min) and the mixing tolerance index increased (from 79 to 35 UF). The sodium stearoyl lactylate (SSL)–diacetyl tartaric acid esters of monoglycerides (DATEM) mixture increased hardness and resistance to extension on dough, whilst dough containing Polysorbate 80 (PS80) was softer; nevertheless, both types of dough retained less CO2. An optimized concentration of the three emulsifiers (0.24% SSL, 0.18% PS80, 0.08% DATEM, w/w) was obtained by surface response methodology. The bread prepared with this combination of emulsifiers presented a considerable specific volume with a very soft crumb.Fil: Gómez, Analía Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Investigaciones en Criotecnología de Alimentos (i); Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; ArgentinaFil: Buchner, Diana . Universidade de Sao Paulo; BrasilFil: Tadini, Carmen C. . Universidade de Sao Paulo; BrasilFil: Añon, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Investigaciones en Criotecnología de Alimentos (i); Argentina. Universidad Nacional de La Plata; ArgentinaFil: Puppo, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Investigaciones en Criotecnología de Alimentos (i); Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; Argentin

Correlation of average hydrophobicity, water/air interface surface rheological properties and foaming properties of proteins

A comparative study on the behavior in the air–water interface of b-lactoglobulin, a-lactoalbumin, glycinin and b-conglycinin was performed. The behavior at the interface was evaluated by equilibrium surface tension and surface rheological properties of adsorbed films. There were significant differences (a 0.05) in the values of the constants of adsorption to the interface of the four proteins. The glycinin had the slowest rate of adsorption, due to its low average hydrophobicity, low molecular flexibility and large molecular size. Smaller proteins like b-lactoglobulin and a-lactoalbumin tended to greater equilibrium pressure values than the larger proteins because of its higher rate of adsorption to the interface. The foam capacity of proteins showed a positive correlation with the average hydrophobicity; the maximal retained liquid volume or the initial rate of passage of liquid to foam were significantly lower (a 0.05) when protein was glycinin. The dilatational modulus of glycinin was the lowest, which implies lowest resistance to disruption of the film. Glycinin protein has lower proportion of gravitational drainage and higher disproportionation having perhaps a less resistant film. In conclusion, b-conglycinin and whey proteins showed a similar behavior, so b-conglycinin might be the best soybean protein to replace milk proteins in food formulations.Fil: Medrano, A.. Universidad de la Republica; UruguayFil: Abirached, C.. Universidad de la Republica; UruguayFil: Araujo, A. C.. Universidad de la Republica; UruguayFil: Panizzolo, L. A.. Universidad de la Republica; UruguayFil: Moyna, P.. Universidad de la Republica; UruguayFil: Añon, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigaciones en Criotecnología de Alimentos (i); Argentina. Universidad Nacional de La Plata; Argentin

Thermal behavior and hydration properties of yeast proteins from Saccharomyces cerevisiae and Kluyveromyces fragilis

High pressure homogenization of yeast cells followed by incubation at 50°C for the dissociation of ribonucleic acid-protein complexes resulted in a high denaturation degree of isolated proteins. Proteins in intact cells exhibited an ample endothermic peak with peak temperatures (T(P)) at 66.66 and 63.67°C for S. cerevisiae and K. fragilis, respectively. No differences were found with respect to the associated enthalpy changes for both studied species. The isolation of proteins from its biomass shifts T(P) to values around 50°C. Impurities such as nucleic acid, polysaccharides and other intracellular components seem to play a protective role upon denaturation. Isolated proteins showed solubilities lower than 40% but exhibited water retention properties and wettability from 3.5 to 7.0 ml of water/g of protein.Fil: Otero, Miguel A.. Instituto Cubano de Investigaciones de los Derivados de la Caña de Azúcar; CubaFil: Wagner, Jorge Ricardo. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Vasallo, María C.. Instituto Cubano de Investigaciones de los Derivados de la Caña de Azúcar; CubaFil: García, Lourdes. Instituto Cubano de Investigaciones de los Derivados de la Caña de Azúcar; CubaFil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentin

A Study of Fundamental and Empirical Rheology Properties of Pan Bread Dough

The effect of maize resistant starch (MRS) and transglutaminase (TG) on rheological and thermal properties of pan bread dough was studied. The MRS was added as an alternative to increase the fiber ingestion while TG supplies the gluten dilution, catalyzing protein bonds. A second order central composite design (22) with three central and four star points was applied, and the results were compared to those of pan bread dough prepared without MRS and TG, as control. The presence of MRS and TG significantly (P < 0.05) influenced the maximum resistance to extension achieving the highest value for the dough formulated with 8.8 g/100 g of MRS and 0.12 g/100 g of TG. A modified power-law model was fitted to the stress–strain data obtained from biaxial test, indicating that partial substitution of wheat flour by MRS resulted high n index (degree of strain hardening). Only starch gelatinization enthalpy significantly changed (P < 0.05) by MRS and TG contents, increasing with the increase of TG. The temperatures obtained from thermograms are compared to those obtained from DSC curves from aqueous suspensions of MRS, indicating gelatinization temperatures above 100 °C.Fil: Sanchez, Diana B.O.. Universidade de Sao Paulo; BrasilFil: Puppo, Maria Cecilia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Ribotta, Pablo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina. Unidad Ceprocor. Cordoba; ArgentinaFil: Leon, Alberto Edel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina. Unidad Ceprocor. Cordoba; ArgentinaFil: Tadini, Carmen C.. Universidade de Sao Paulo; Brasi

Effects of drying conditions on some physical properties of soy protein films

The influence of drying conditions (air temperature and relative humidity) on mechanical properties, solubility in water, and color of two kinds of soy protein isolate film: a commercial one (CSPI) and other obtained under laboratory conditions (LSPI) were evaluated using the response surface methodology (RSM). Soy protein films were prepared by casting using glycerol as plasticizer. The films were dried in a chamber with air circulation under controlled conditions of relative humidity (24%, 30%, 45%, 60%, 66%) and air temperature (34, 40, 55, 70, 76 _C). It was verified that mechanical properties of films made from LSPI and CSPI are influenced in a very different way by the drying conditions due to a diverse initial protein conformation in both materials, as was revealed by DSC and SDS–Page studies. The solubility of the LSPI film was affected by temperature and relative humidity, being lowest (_50%) for films obtained at high RH and temperatures ranging from 45 to 76 _C. For CSPI films, in contrast, solubility did not depend on the drying process and it remained relatively constant (_40%). The optimal drying conditions determined by RSM were: 70 _C and 30% RH for CSPI films and 60 _C and 60% RH for LSPI films. Dried under these conditions, CSPI films presented a higher tensile strength, lower elongation at break, lower solubility and better water and oxygen permeability than LSPI ones.Fil: Denavi, Gabriela Alejandra. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Tapia Blacido, D. R.. Universidade Estadual de Campinas; BrasilFil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Sobral, P. J. A.. Universidade de Sao Paulo; BrasilFil: Mauri, Adriana Noemi. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Menegalli, F. C.. Universidade Estadual de Campinas; Brasi

Effect of general anaesthesia on functional outcome in patients with anterior circulation ischaemic stroke having endovascular thrombectomy versus standard care: a meta-analysis of individual patient data

Background: General anaesthesia (GA) during endovascular thrombectomy has been associated with worse patient outcomes in observational studies compared with patients treated without GA. We assessed functional outcome in ischaemic stroke patients with large vessel anterior circulation occlusion undergoing endovascular thrombectomy under GA, versus thrombectomy not under GA (with or without sedation) versus standard care (ie, no thrombectomy), stratified by the use of GA versus standard care. Methods: For this meta-analysis, patient-level data were pooled from all patients included in randomised trials in PuMed published between Jan 1, 2010, and May 31, 2017, that compared endovascular thrombectomy predominantly done with stent retrievers with standard care in anterior circulation ischaemic stroke patients (HERMES Collaboration). The primary outcome was functional outcome assessed by ordinal analysis of the modified Rankin scale (mRS) at 90 days in the GA and non-GA subgroups of patients treated with endovascular therapy versus those patients treated with standard care, adjusted for baseline prognostic variables. To account for between-trial variance we used mixed-effects modelling with a random effect for trials incorporated in all models. Bias was assessed using the Cochrane method. The meta-analysis was prospectively designed, but not registered. Findings: Seven trials were identified by our search; of 1764 patients included in these trials, 871 were allocated to endovascular thrombectomy and 893 were assigned standard care. After exclusion of 74 patients (72 did not undergo the procedure and two had missing data on anaesthetic strategy), 236 (30%) of 797 patients who had endovascular procedures were treated under GA. At baseline, patients receiving GA were younger and had a shorter delay between stroke onset and randomisation but they had similar pre-treatment clinical severity compared with patients who did not have GA. Endovascular thrombectomy improved functional outcome at 3 months both in patients who had GA (adjusted common odds ratio (cOR) 1·52, 95% CI 1·09–2·11, p=0·014) and in those who did not have GA (adjusted cOR 2·33, 95% CI 1·75–3·10, p&lt;0·0001) versus standard care. However, outcomes were significantly better for patients who did not receive GA versus those who received GA (covariate-adjusted cOR 1·53, 95% CI 1·14–2·04, p=0·0044). The risk of bias and variability between studies was assessed to be low. Interpretation: Worse outcomes after endovascular thrombectomy were associated with GA, after adjustment for baseline prognostic variables. These data support avoidance of GA whenever possible. The procedure did, however, remain effective versus standard care in patients treated under GA, indicating that treatment should not be withheld in those who require anaesthesia for medical reasons