Time filter

Source Type

San Juan Bautista Tuxtepec, Mexico

Ruiz-Lopez I.I.,Tuxtepec Institute of Technology | Castillo-Zamudio R.I.,Colegio de Mexico | Salgado-Cervantes M.A.,Instituto Tecnologico De Veracruz | Rodriguez-Jimenes G.C.,Instituto Tecnologico De Veracruz | Garcia-Alvarado M.A.,Instituto Tecnologico De Veracruz
Food and Bioprocess Technology | Year: 2010

The study of mass transfer during osmotic dehydration process in limited volume solutions was carried out to evaluate the diffusion coefficients of sucrose and water in the osmotic treatment of hexahedral pineapple slices. The experimental osmotic dehydration kinetics for pineapple slices of two different sizes were conducted at 25 °C using a 1:1 solution to fruit weight ratio. The analytical solution of a 3D mass transfer model considering a limited volume of osmotic solution (i. e., an osmotic media of variable solute concentration) was used for describing the mass transfer in osmotic dehydration of pineapple slices. This model was fitted to the experimental kinetics by means of nonlinear regression to obtain the diffusion coefficients. Additionally, the diffusion coefficients were evaluated considering an infinite volume of osmotic solution (i. e., an osmotic media of constant solute concentration). Results showed that the proposed model may be fitted accurately to the experimental osmotic dehydration kinetics and allows the estimation of diffusion coefficients when solute concentration in the osmotic media varies along the process. © 2008 Springer Science + Business Media, LLC. Source

Teran G.,ESIQIE | Capula-Colindres S.,National Polytechnic Institute of Mexico | Angeles-Herrera D.,Mexican Institute of Petroleum | Velazquez J.C.,ESIQIE | Fernandez-Cueto M.J.,Tuxtepec Institute of Technology
Engineering Fracture Mechanics | Year: 2016

This work presents, for the first time, and estimation of fracture toughness KIC correlations from Charpy V-notch (CVN) impact test data extracted from T-welded connections repaired with rectangular grinding and filled by wet welding. To obtain KIC values, equations based on the yield stress (σYS) of the wet welding beads were used. The estimated KIC data decreased with increasing water depth. These two characteristics (porosity and microstructures for low carbon steels) did not improve the mechanical properties, such as Charpy impact and KIC values. © 2015 Elsevier Ltd. Source

Perez Silva A.,Tuxtepec Institute of Technology | Gunata Z.,Montpellier University | Lepoutre J.-P.,French National Institute for Agricultural Research | Odoux E.,CIRAD - Agricultural Research for Development
Food Research International | Year: 2011

Green vanilla beans were subjected to the traditional curing process in Mexico. Odor-active potential from beans including 23 compounds was monitored through the analysis of both free and glucosidically bound volatiles. 8 of them were aliphatic aldehydes, acids, alcohol and ketone. 15 molecules were shikimate derivatives in which 13 were detected in glucosylated form. Some glucosides were efficiently hydrolyzed while some others partly or not at all after 90. days of curing. Moreover kinetics of hydrolysis of glucosides were not the same. A major part of glucovanillin was hydrolyzed at the first stages of curing while some other glucosides at the advanced stages. Data support hypothesis that hydrolysis of glucosides during curing is rather enzymatic origin than chemical one. Free shikimate derivatives or those liberated from glucosides are prone to chemical or enzymatic interconversions leading to a significant change in the aroma profile of cured vanilla. © 2011 Elsevier Ltd. Source

Pacheco-Angulo H.,Instituto Tecnologico De Veracruz | Herman-Lara E.,Tuxtepec Institute of Technology | Garcia-Alvarado M.A.,Instituto Tecnologico De Veracruz | Ruiz-Lopez I.I.,Autonomous University of Puebla
Food and Bioproducts Processing | Year: 2016

The aim of this study was to model both the dynamic and equilibrium mass transfer periods for water, osmotic solute and food solids interchange between product and solution during an osmotic dehydration (OD) process. The OD model is able to represent situations where concentration of osmotic media changes during the process or where interfacial resistance to mass transfer cannot be neglected. Water and solute are considered to move within the product by a diffusion mechanism based on Fick's second law, while external convective mass transfer is considered in the fluid. The state-space form of the model is analytically solved for one-dimensional mass transfer in products with flat slab, infinite cylinders and sphere geometries. The developed theory was applied to the analysis of equilibrium and OD dehydration curves of carrot slices obtained at 40 °C in sodium chloride solutions with and without stirring and different ratios between solution volume and product mass. Water and NaCl diffusivities were identified in the narrow ranges of 6.0-7.6 × 10-10 m2/s and 3.5-4.1 × 10-10 m2/s, respectively, demonstrating the applicability of the proposed model under a wide range of operating conditions. © 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved. Source

Ruiz-Lopez I.I.,Autonomous University of Puebla | Huerta-Mora I.R.,Tuxtepec Institute of Technology | Vivar-Vera M.A.,Tuxtepec Institute of Technology | Martinez-Sanchez C.E.,Tuxtepec Institute of Technology | Herman-Lara E.,Tuxtepec Institute of Technology
Drying Technology | Year: 2010

In this study the effect of osmotic dehydration (OD) on the air-drying kinetics of chayote (Sechium edule (Jacq.) Swartz) fruits was investigated. Fresh and osmotically dehydrated chayote parallelepipeds (1x1x2 and 4x4x2 cm) were subjected to convective drying at air temperatures of 50 and 60°C, with air velocities of 1.5 and 2.5 m/s. The OD pretreatments were performed in 10 and 25% NaCl solutions (w/w) at 25°C during 3 h using a solution-tofruit mass ratio of 4:1. The use of higher air velocities notably accelerated drying rates as manifested through significantly higher drying rate constants estimated with Page's model, whereas no effect of temperature was observed. A previously reported analytical solution that considers both product shrinkage and variable diffusivity was generalized to describe the drying kinetics of food products with parallelepiped geometry. Selected drying experiments were then fitted to this solution using six different sets of model assumptions. Results indicated that product shrinkage is the main factor to be considered in order to estimate reliable values for diffusion coefficients. The OD pretreatments produced a significant reduction of the initial moisture content of chayote slabs before drying, thus allowing shorter drying time, which may lead to reduced energy consumption. © 2010 Taylor & Francis Group, LLC. Source

Discover hidden collaborations