Influence of air temperature on drying kinetics and antioxidant potential of olive pomace

This work aims to evaluate the influence of olive pomace drying (a solid by-product of the olive oil industry) on both antioxidant potential and drying kinetics. The two main fractions of olive pomace (pits, PI and pulps + peels, P + P) were characterized by image analysis and density measurement. The drying process was analyzed in experiments carried out at different temperatures (from 50 to 150 C) and mathematically described from the diffusion and Weibull models. The antioxidant potential of the extracts (ethanol water 80:20 v/v, 22 ± 1 C, 170 rpm for 24 h) obtained from the dry product was analyzed by measuring the total phenolic content and antioxidant capacity and the main polyphenols were quantified by HPLC DAD/MS MS. The drying behavior of olive pomace was well described by considering the diffusion in the PI and P + P fractions separately and the influence of temperature on effective moisture diffusivities was quantified by an Arrhenius type equation. The antioxidant potential was only mildly influenced by the drying temperature. However, long drying times at the highest temperature tested (150 C) significantly (p < 0.05) increased the antioxidant potentialThe authors acknowledge the Generalitat Valenciana (PROMETEO/2010/062 and PROMETEO/2012/007) and Ministerio de Economia y Competitividad (AGL2011-29857-C03-04) for their financial support and the Ministerio de Educacion, Cultura y Deporte of Spain for the financing through the Formacion de Profesorado Universitario del Programa Nacional de Formacion de Recursos Humanos de Investigacion.Ahmad-Qasem Mateo, MH.; Barrajón Catalán, E.; Micol, V.; Cárcel Carrión, JA.; García Pérez, JV. (2013). Influence of air temperature on drying kinetics and antioxidant potential of olive pomace. Journal of Food Engineering. 119(3):516-524. https://doi.org/10.1016/j.jfoodeng.2013.06.027S516524119

Ultrasonically enhanced low-temperature drying of apple: Influence on drying kinetics and antioxidant potential

[EN] Low-temperature air drying represents an alternative means to hot air drying of better retaining the sensory, nutritional and functional properties of foods. However, reducing the air temperature to figures below the product s freezing point involves low drying rates, which largely places constraints on any further industrial application. The main aim of this work was to evaluate the feasibility of using power ultrasound to improve the low-temperature drying of apple, considering not only the kinetic effects but also the influence on the antioxidant potential of the dried apple. For that purpose, apple (Malus domestica cv. Granny Smith) cubes (8.8 mm side) were dried (2 m/s and a relative humidity of under 10%) at low temperatures ( 10, 5, 0, 5 and 10 C) with (20.5 kW/m3) and without ultrasound application. The drying kinetics were modeled by considering the diffusion theory, negligible shrinkage and cubic geometry. In the dried apple, total phenolic and flavonoid contents and antioxidant capacity were measured. The application of power ultrasound sped up the drying kinetics at every temperature tested, achieving drying time reductions of up to 77%, which was linked to the improvement in diffusion and convective mass transport. In overall terms, ultrasound application involved a greater degradation of polyphenol and flavonoid contents and a reduction of the antioxidant capacity, which was related to the cell disruption caused by the mechanical stress of acoustic waves.The authors acknowledge the financial support of the Spanish Ministerio de Economia y Competitividad (MINECO), the European Union (FEDER) and the Generalitat Valenciana (from the projects DPI2012-37466-CO3-03, DPI2012-37466-CO3-02, PROMETEO/2010/062 and the FPI fellowship granted to J.V. Santacatalina).Santacatalina Bonet, JV.; Rogríguez, Ó.; Simal, S.; Cárcel Carrión, JA.; Mulet Pons, A.; García Pérez, JV. (2014). Ultrasonically enhanced low-temperature drying of apple: Influence on drying kinetics and antioxidant potential. Journal of Food Engineering. 138:35-44. https://doi.org/10.1016/j.jfoodeng.2014.04.003S354413

Desarrollo de software sensible al contexto

Los Sistemas Informáticos fueron evolucionando desde aplicaciones científicas, comerciales y de escritorio, hasta el momento actual, en que pueden brindar servicios de acuerdo a la ubicación, tiempo y perfil del usuario. Las aplicaciones que brindan este tipo de funcionalidad se denominan Aplicaciones Sensibles al Contexto (CA – Context Aware), donde tienen predominancia los dispositivos móviles y el perfil del usuario. También va cambiando la forma de uso de la computadora, evolucionando desde brindar servicios a pedido del usuario hasta brindarlos en forma automática y extender la percepción y la interacción del usuario con el mundo real (realidad aumentada). La Ingeniería de Aplicaciones CA se ocupa de proporcionar un enfoque sistematizado para desarrollar este tipo de aplicaciones. El propósito de este proyecto es abarcar los aspectos de Ingeniería de Software para el desarrollo de aplicaciones CA.Eje: Ingeniería de SoftwareRed de Universidades con Carreras en Informática (RedUNCI

Mechanical behavior of asphalt mixtures containing silica gels as warm additives

This paper presents the results of a study of some compounds capable of absorbing water into their structure (silica gel), as potential foaming binders. Asphalt mixtures were manufactured at different manufacturing and compaction temperatures, using four different silica gels. Static and dynamic tests were carried out to determine their behavior in asphalt mixtures. The results were compared with those obtained using hot-mix asphalt and warm-mix asphalt manufactured with zeolite. The lab results showed a similar behavior of asphalt mixtures containing either silica gel or zeolite.The research presented herein was sponsored by the Research Office of Universidad de La Frontera (DIUFRO) under the project number DI15-0089

Estimation of composition of quinoa (Chenopodium quinoa Willd.) grains by Near-Infrared Transmission spectroscopy

The aim of this study was to develop robust chemometric models for the routine determination of dietary constituents of quinoa (Chenopodium quinoa Willd.) using Near-Infrared Transmission (NIT) spectroscopy. Spectra of quinoa grains of 77 cultivars were acquired while dietary constituents were determined by reference methods. Spectra were subjected to multiplicative scatter correction (MSC) or extended multiplicative signal correction (EMSC), and were (or not) treated by Savitzky-Golay (SG) filters. Latent variables were extracted by partial least squares regression (PLSR) or canonical powered partial least squares (CPPLS) algorithms, and the accuracy and predictability of all modelling strategies were compared. Smoothing the spectra improved the accuracy of the models for fat (root mean square error of cross-validation, RMSECV: 0.3190.327%), ashes (RMSECV: 0.2240.230%), and particularly for protein (RMSECV: 0.5180.564%) and carbohydrates (RMSECV: 0.5420.559%), while enhancing the prediction performance, particularly, for fat (root mean square error of prediction, RMSEP: 0.2480.335%) and ashes (RMSEP: 0.1370.191%). Although the highest predictability was achieved for ashes (SG-filtered EMSC/PLSR: bootstrapped 90% confidence interval for RMSEP: [0.3760.512]) and carbohydrates (SG-filtered MSC/CPPLS: 90% CI RMSEP: [0.6510.901]), precision was acceptable for protein (SG-filtered MSC/CPPLS: 90% CI RMSEP: [0.6500.852]), fat (SG-filtered EMSC/CPPLS: 90% CI RMSEP: [0.4780.654]) and moisture (non-filtered EMSC/PLSR: 90% CI RMSEP: [0.6580.833]).Mr. Encina-Zelada acknowledges the financial aid provided by the Peruvian National Programme of Scholarships and Student Loans (PRONABEC) in the mode of PhD grants (Presidente de La República Grant Number 183308). Dr. Gonzales-Barron wishes to acknowledge the financial support provided by the Portuguese Foundation for Science and Technology (FCT) through the award of a five-year Investigator Fellowship (IF) in the mode of Development Grants (IF/00570)

Mathematical modeling of convective air drying of quinoa-supplemented feed for laboratory rats

Drying kinetics of quinoa-supplemented feed for laboratory rats during processing at 50, 60, 70, 80 and 90ºC was studied and modeled in this work. Desorption isotherm was obtained at 60ºC giving a monolayer moisture content of 0.04 g water/g d.m. The experimental drying curves showed that drying process took place only in the falling rate period. Several thin-layer drying equations available in the literature were evaluated based on determination coefficient (r²), sum squared errors (SSE) and Chi-square (&#967;2) statisticals. In comparison to the experimental moisture values, the values estimated with the Logarithmic model gave the best fit quality (r² >0.994, SSE < 0.00015 and &#967;2 < 0.00018), showing this equation could predict very accurately the drying time of rat feed under the operative conditions applied