Browsing by Author "Enrione, Javier"

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    A non-destructive digital imaging method to predict immobilized yeast-biomass
    (ELSEVIER, 2009) Acevedo, Cristian A.; Skurtys, Olivier; Young, Manuel E.; Enrione, Javier; Pedreschi, Franco; Osorio, Fernando
    In food fermentation, many types of immobilization systems are used, such as hydrogel entrapment, where alginate is the main biopolymer. one of the important problems in industrial processes is the quantifications of biomass, since the traditional system of direct cell counting cannot be used. In this study, a simple digital imaging method to determine the biomass of yeasts immobilized into alginate capsules was developed. Important evidence of the yeasts growing inside the alginate was the change in the surface color of the capsule. Digital images were taken with different biomass concentration, and the RGB-analysis showed significant differences in the blue field. The histogram of the blue channel was used to develop a PLS multivariate calibration to predict biomass concentration. The method was validated in primary beer fermentation with good efficiency. (C) 2009 Elsevier Ltd. All rights reserved.
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    A Quinoa Protein Hydrolysate Fractionated by Electrodialysis with Ultrafiltration Membranes Improves Maternal and Fetal Outcomes in a Mouse Model of Gestational Diabetes Mellitus
    (2023) Busso, Dolores; Gonzalez, Adrian; Santander, Nicolas; Saavedra, Fujiko; Quiroz, Alonso; Rivera, Katherine; Gonzalez, Javier; Olmos, Pablo; Marette, Andre; Bazinet, Laurent; Illanes, Sebastian; Enrione, Javier
    ScopeQuinoa intake exerts hypoglycemic and hypolipidemic effects in animals and humans. Although peptides from quinoa inhibit key enzymes involved in glucose homeostasis in vitro, their in vivo antidiabetic properties have not been investigated.Methods and resultsThis study evaluated the effect of oral administration of a quinoa protein hydrolysate (QH) produced through enzymatic hydrolysis and fractionation by electrodialysis with ultrafiltration membrane (EDUF) (FQH) on the metabolic and pregnancy outcomes of Lepdb/+ pregnant mice, a preclinical model of gestational diabetes mellitus. The 4-week pregestational consumption of 2.5 mg mL-1 of QH in water prevented glucose intolerance and improves hepatic insulin signaling in dams, also reducing fetal weights. Sequencing and bioinformatic analyses of the defatted FQH (FQHD) identified 11 peptides 6-10 amino acids long that aligned with the quinoa proteome and exhibited putative anti-dipeptidyl peptidase-4 (DPP-IV) activity, confirmed in vitro in QH, FQH, and FDQH fractions. Peptides homologous to mouse and human proteins enriched for biological processes related to glucose metabolism are also identified.ConclusionProcessing of quinoa protein may be used to develop a safe and effective nutritional intervention to control glucose intolerance during pregnancy. Further studies are required to confirm if this nutritional intervention is applicable to pregnant women.
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    Prediction of the Glass Transition Temperature on Extruded Waxy Maize and Rice Starches in Presence of Glycerol
    (Springer Nature, 2010) Enrione, Javier; Osorio, Fernando; Pedreschi Plasencia, Franco; Hill, Sandra
    Polymer science approach has shown to be useful to understand the structural complexity of food systems. This work looks at the effect of glycerol (5%, 10%, and 20% (dry weight basis)) on the glass transition temperature (Tg) of a starchy matrix determined by DSC and its prediction using Ten-Brinke-Karasz equation. Waxy maize starch (WMS) and rice starch (RS) systems were prepared by thermomechanical extrusion. A decrease in Tg, from similar to 170 to similar to 25 A degrees C, was detected for both starches (0% glycerol) when the moisture increased from 5% to 25% (wet weight basis (wb)). When glycerol was added, a further decrease in Tg was obtained. Tg was reduced from 120 to 60 A degrees C and 45 A degrees C for 10% and 20% glycerol, respectively, at a moisture content of 10% (wb). A direct comparison between starches with similar composition showed equal Tg (P > 0.05). The modeling for the control samples (0% glycerol) gave a Delta Cp similar to aEuro parts per thousand 0.4 Jg(-1) K-1 for WMS and RS and similar to 1.9 Jg(-1) K-1 for water. These values can be explained by the well-known Tg dependence on degree of polymerization and molecular weight. When the glycerol concentration was increased, an increase was observed, Delta Cp similar to aEuro parts per thousand 0.6 Jg(-1) K--1,K- for both starches and similar to 2.8 Jg(-1) K-1 for water. This behavior would indicate an overestimation in the plasticizing effect of glycerol due to the possible occurrence of polyol-rich fractions in the extruded samples.
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    Sorption Behavior of Extruded Rice Starch in the Presence of Glycerol
    (Wiley-Blackwell, 2010) Enrione, Javier; Hill, Sandra; Mitchell, John R.; Pedreschi Plasencia, Franco
    The modeling approach to predict the sorption behavior of nonelectrolytic mixtures has been related to moisture content at a specifi c equilibrium relative humidity (ERH) and to the component weight fraction in the system. The work presented here attempts to identify deviations of the predicted sorption profi le of a model system based on rice starch and glycerol. Accurate sorption isotherms (25 ° C) were obtained by using dynamic vapor sorption (DVS) for the ERH range of 0% - 90%. The glass transition temperature (Tg) of the samples was obtained by differential scanning calorimetry (DSC). Sorption studies show a reduction in moisture content for an ERH of 60% in the presence of glycerol. This behavior was represented by a reduction in Guggenheim - Anderson - de Boer (GAB) modeling parameters, the monolayer value (from 8.9% to 6.6%); a reduction in the constant related to the net heat of sorption (from 6.4 to 3.5); and an increase in the constant related to the heat of sorption at the multilayer (from 0.72 to 0.94). The sorption profi les of the starch - glycerol mixtures were also modeled using sorption isotherms and moisture contents from each component. The estimated interaction factor of 1 indicated a reduction in water uptake specifi cally for an ERH of 60%. The 10% and 20% glycerol systems showed a signifi cant increase in independent interaction factors (IIFs) from 0.6 to 0.9, suggesting a relationship between water uptake and the matrix - polyol interaction. This behavior was related to the molecular mobility of the system, as indicated by plotting IIF versus T T g ( T = 25 ° C).
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    Using RGB Image Processing for Designing an Alginate Edible Film
    (2012) Acevedo, Cristian A.; Lopez, Dario A.; Tapia, Maria J.; Enrione, Javier; Skurtys, Olivier; Pedreschi, Franco; Brown, Donald I.; Creixell, Werner; Osorio, Fernando
    The use of edible films to coat food products is a technique that allows for an extended shelf-life. One of the most widely used polymers is calcium alginate. However, this polymer can modify the original food color and the perception by consumers. The objective was to design an alginate film based principally on color changes using a RGB color model. Edible films were prepared with sodium alginate and glycerol as plasticizer, cross-linking the polymer with calcium. Dry and hydrated states of the edible films were studied. Film thickness was directly proportional to surface concentration and increased with hydration. There is a zone in which the color does not change with alginate surface concentration and another where the color is directly proportional to it. This latter scenario is not a consequence of structural changes or the degree of hydration. Results showed a range where the color was not modified by the alginate concentration; hence, an optimal surface concentration was determined as a design parameter. Edible films made using the optimal surface concentration would not mask microbial contamination and have good physical properties (water vapor transmission and swelling) compared with other surface concentrations. In addition, it was possible to model alginate surface concentration as a function of surface color using mathematical tools (clustering, linear regression, and support vector machine), allowing one to study the optimal use of the edible films.