Antonio Mulet - Profile on Academia.edu (original) (raw)
Papers by Antonio Mulet
LCA of integrated orange production in the Comunidad Valenciana (Spain)
ABSTRACT
Power ultrasound application on convective drying of foodstuffs may be considered an emergent tec... more Power ultrasound application on convective drying of foodstuffs may be considered an emergent technology. Acoustic energy may improve drying rate without significantly heating the material due to phenomena affecting mass transfer resistances. As a consequence, ultrasound application on the drying of heat sensitive materials or in process carried out at low temperatures is quite interesting. The aim of this work was to address the influence of the main processing variables on the convective drying assisted by power ultrasound (21.7 kHz) of different foodstuffs. The influence of air velocity and temperature, raw material characteristics, mass load density and ultrasonic power applied was addressed. From the experimental results, a significant influence of the application of power ultrasound on both external and internal resistance to mass transfer has been found. Nevertheless, the ultrasonic effects depended strongly on the experimental conditions used. In the case of carrot drying at different temperatures, the application of power ultrasound increased the effective moisture diffusivity by 55 % at experiments carried out at 30 ºC, however the improvement was non significant at experiments conducted at 70 ºC.
Transmisión de calor por conducción / A. Mulet, José Bon
MODELIZACIÓN Y OPTIMIZACIÓN DE CÁMARAS DE MADURACIÓN
ABSTRACT
Review: Low intensity ultrasonics in food technology
... Keywords : ultrasonics, physical properties, quality control ... Pnlabrrrs C117z,e: ultrasoni... more ... Keywords : ultrasonics, physical properties, quality control ... Pnlabrrrs C117z,e: ultrasonidos, propiedades fisicas, control de calidad ... If the ultrasonic signal finds discontinuities in its path, for example a hole inside a potato, part of the energy will be attenuated, thus reducing the ...
Model-based investigation into atmospheric freeze drying assisted by power ultrasound
Journal of Food Engineering, 2015
ABSTRACT Atmospheric freeze drying consists of a convective drying process using air at a tempera... more ABSTRACT Atmospheric freeze drying consists of a convective drying process using air at a temperature below the freezing point of the processed product, and with a very low relative humidity content. This paper focuses on the use of a simple one-dimensional model considering moving boundary vapor diffusion to describe the ultrasonic assisted atmospheric freeze-drying of foodstuffs. The case study is the drying of apple cubes (8.8 mm) at different air velocities (1, 2, 4 and 6 m/s), temperatures (−5, −10 and −15 °C), without and with (25, 50 and 75 W) power ultrasound application. By fitting the proposed diffusion model to the experimental drying kinetics, the effective diffusivity of water vapor in the dried product was estimated. The model was successfully validated by drying apple samples of different size and geometry (cubes and cylinders). Finally, a 23 factorial design of experiments revealed that the most relevant operating parameter affecting the drying time was the applied ultrasound power level.
Defect and Diffusion Forum, 2008
Microbial Inactivation by Ultrasound Assisted Supercritical Fluids
Physics Procedia, 2015
Temperature influence on the sugar extraction from carob pods
Experiments on the extraction of sugar from carob pods have been carried out at 20, 30, 40 and 50... more Experiments on the extraction of sugar from carob pods have been carried out at 20, 30, 40 and 50 °C respectively, in order to study the temperature effect on the extraction rate. Particle size of the ground pods was between 0.5 and 1 cm. From experimental data and considering only the period where the mass transfer (sugars) occurs by diffusion, a characteristic kinetic equation for this period has been established.
La investigación de los principales efectos de la energía ultrasónica sobre la calidad final de l... more La investigación de los principales efectos de la energía ultrasónica sobre la calidad final de los alimentos deshidratados es básica para evaluar las posibles aplicaciones de esta técnica en la industria alimentaria. El principal objetivo de este estudio fue observar la influencia de los ultrasonidos de baja frecuencia sobre la estructura celular de la patata (Solanum tuberosum L.) deshidratada. Para ello, las muestras de patata de forma cilíndrica (14 mm de diámetro y 4 mm de espesor) fueron secadas utilizando diferentes condiciones: (A) secado convencional con aire, a 19ºC y 68% de humedad relativa, (B) secado aplicando presión estática y succión, a 19ºC y 50% HR, (C) secado aplicando presión, succión y energía ultrasónica (100 W, 20,8 kHz), a 18ºC y 37% HR. En todas las experiencias la velocidad del aire fue de 1,5 m/s. El secado convencional (A) causó una mínima degradación del almidón y las paredes celulares se mantuvieron en buen estado, probablemente debido a la baja temperatura utilizada. Cuando se aplicó presión y succión durante el proceso de secado (B) se pudo observar una degradación importante del almidón, junto a un gran deterioro de las paredes celulares. Dada la relación existente entre la textura y las paredes celulares, las modificaciones observadas pueden ser responsables de la pérdida de calidad de las muestras de patata deshidratadas bajo estas condiciones. En cambio, las muestras de patata deshidratada obtenidas mediante aplicación de energía ultrasónica (C) fueron las que presentaron un mejor aspecto. De hecho, no se detectó deterioro alguno ni del almidón ni de la estructura de las paredes celulares. Por tanto, los resultados obtenidos sugieren la posibilidad de aplicar energía ultrasónica para optimizar la calidad de alimentos deshidratados como en el caso de la patata. No obstante, se necesita una evaluación más exhaustiva tanto de las propiedades texturales como de la capacidad de rehidratación de los productos deshidratados, que permita evaluar de forma más objetiva la posibilidad de implantar de esta nueva técnica en el campo de la alimentación.
A diffusion approach to describe hot air and atmospheric freeze drying kinetics of different products
The main aim of this work was to test a diffusion model to describe atmospheric freeze drying (AF... more The main aim of this work was to test a diffusion model to describe atmospheric freeze drying (AFD) and hot air drying (HAD) kinetics of different products. HAD (50 ºC and 2 ms-1) and AFD (-14 ºC, 2 ms-1) experiments were carried out for eggplant, apple and carrot cubes (side 10 mm). Kinetics were described using a diffusion model neglecting the external resistance to water transfer and the shrinkage of the samples. A good fit was obtained for AFD of apple and carrot, where assumptions considered in the model formulation were properly chosen.
The application of power ultrasound could constitute a way to improve traditional convective dryi... more The application of power ultrasound could constitute a way to improve traditional convective drying systems. There still exists a lack of knowledge on this technology in order to address industrial applications. The aim of this work was to identify the influence of the textural properties of different vegetable products on the ultrasonic assisted convective drying. For that purpose, experimental drying kinetics (40 ºC and 1 m/s) of different vegetable products (orange and lemon peel, carrot, potato and eggplant) were carried out applying different ultrasonic powers (0, 6, 12, 18, 25, 30 and 37 kW/m3). In every product, a similar diffusion model was used to identify an average effective diffusivity for the different ultrasonic powers. Product’s textural properties were assessed by Textural Profile Analysis (TPA). Linear relationships were established between the identified effective diffusivity and the applied ultrasonic power for the different products. The positive slopes of the li...
Quality assessment of dried eggplant using different drying methods: hot air drying, vacuum freeze drying and atmospheric freeze drying
Dehydration constitutes a traditional preservation method for fruits and vegetables and it repres... more Dehydration constitutes a traditional preservation method for fruits and vegetables and it represents a very important operation in food processing. The way how water is removed from food affects the final product quality, thus the characteristics of dried products are dependent on the drying technique used. The main objective of the present study was to evaluate the effect of different drying techniques on the quality of dried eggplant. For this purpose, cubic samples (10 mm side) were obtained from the flesh of Spanish origin eggplants (Solanum melongena var. Black Enorma). Three different drying techniques were applied: hot air drying (HAD, 50 ºC and 2 m/s), atmospheric freeze drying (AFD, -14 ºC and 2 m/s) and vacuum freeze drying (VFD). The drying kinetics of HAD and AFD were determined by weighing the samples at preset times during the process. To evaluate the influence of drying method on the final quality of the product, rehydration kinetics of HAD, AFD and VFD samples were ...
There is an increasing interest in process intensification by introducting alternative techniques... more There is an increasing interest in process intensification by introducting alternative techniques. This is the case of conventional drying process, usually characterized by large processing time with high energy demand and influence on the final quality of the products. The application of ultrasound could contribute to reduce the drying time when mild conditions (low air velocity and temperature) have to be applied to preserve the final quality. Ultrasound application reduces both the external and internal resistance to mass transfer, that could contribute to reduce operating and energy costs and increase the productivity.
Experiencia de laboratorio: estudio del comportamiento dinámico de un termopar. Influencia de la velocidad del fluido
Intermittent drying technology implements varying-time operating conditions to improve process en... more Intermittent drying technology implements varying-time operating conditions to improve process energy efficiency in comparison with other conventional convective drying techniques. One method of intermittent drying involves heating and resting periods. In heating periods, hot air removes the moisture and increases the material temperature by forced convection. In resting (or tempering) periods, the change of the temperature and moisture content takes place without heat supply by free convection. The mass transfer phenomena that take place during resting period may be modified by power ultrasound application. External resistance to mass transfer may be affected by pressure variations, oscillating velocities and microstreaming at the solid-gas interfaces. Internal resistance may be reduced by alternating expansion and compression cycles produced by ultrasound in the material and also through some effects on the interfaces of intercellular spaces, which may contribute to faster water d...
The final composition of cheese products constitutes one of their quality attributes and its know... more The final composition of cheese products constitutes one of their quality attributes and its knowledge in quality control is important. The measurement of ultrasonic velocity is a non-destructive technique, which allows the determination of foodstuff composition. Ultrasonic velocities in both cheese analogues and commercial cheese spreads were determined at different temperatures. The protein, fat and moisture contents of the samples ranged between 8.54 and 12.1 % (wb), 0.2 and 30.1 % (wb) and 57.5 and 81 % (wb), respectively. At 18ºC the ultrasonic velocity was not dependent on the cheese composition. The ultrasound velocity increased with the increase of fat content at temperatures lower than 18ºC and decreased for higher temperatures. From ultrasonic velocity measurements on cheese analogues, a model was developed to correlate the ultrasonic velocity, temperature and composition. This model allowed a good assessment of the composition of independent samples of cheese spreads.
Journal of Food Engineering, 2015
ABSTRACT The daily challenge involved in operating a process is the attainment of the objectives.... more ABSTRACT The daily challenge involved in operating a process is the attainment of the objectives. Process management requires the use of tools adapted to the system’s complexity. In order to obtain real time results, simplified mechanistic modelling offers a way to deal with this. To this end, carob pod (Ceratonia Siliqua, L.) kibbles extraction is addressed in this work. They are a source of different, valuable components and have a complex structure and a highly variable concentration of components. The components considered are sugars and soluble polyphenols. Obtaining the extracts with an optimal composition of a particular component, while avoiding or limiting other components in the extract, is a challenge to be addressed. Two steps can be considered: solubilization and diffusion, modelled by means of a first order reaction and by considering slab geometry. The optimal processing time and temperature are obtained by taking a particular kibble size and composition into account.
LCA of integrated orange production in the Comunidad Valenciana (Spain)
ABSTRACT
Power ultrasound application on convective drying of foodstuffs may be considered an emergent tec... more Power ultrasound application on convective drying of foodstuffs may be considered an emergent technology. Acoustic energy may improve drying rate without significantly heating the material due to phenomena affecting mass transfer resistances. As a consequence, ultrasound application on the drying of heat sensitive materials or in process carried out at low temperatures is quite interesting. The aim of this work was to address the influence of the main processing variables on the convective drying assisted by power ultrasound (21.7 kHz) of different foodstuffs. The influence of air velocity and temperature, raw material characteristics, mass load density and ultrasonic power applied was addressed. From the experimental results, a significant influence of the application of power ultrasound on both external and internal resistance to mass transfer has been found. Nevertheless, the ultrasonic effects depended strongly on the experimental conditions used. In the case of carrot drying at different temperatures, the application of power ultrasound increased the effective moisture diffusivity by 55 % at experiments carried out at 30 ºC, however the improvement was non significant at experiments conducted at 70 ºC.
Transmisión de calor por conducción / A. Mulet, José Bon
MODELIZACIÓN Y OPTIMIZACIÓN DE CÁMARAS DE MADURACIÓN
ABSTRACT
Review: Low intensity ultrasonics in food technology
... Keywords : ultrasonics, physical properties, quality control ... Pnlabrrrs C117z,e: ultrasoni... more ... Keywords : ultrasonics, physical properties, quality control ... Pnlabrrrs C117z,e: ultrasonidos, propiedades fisicas, control de calidad ... If the ultrasonic signal finds discontinuities in its path, for example a hole inside a potato, part of the energy will be attenuated, thus reducing the ...
Model-based investigation into atmospheric freeze drying assisted by power ultrasound
Journal of Food Engineering, 2015
ABSTRACT Atmospheric freeze drying consists of a convective drying process using air at a tempera... more ABSTRACT Atmospheric freeze drying consists of a convective drying process using air at a temperature below the freezing point of the processed product, and with a very low relative humidity content. This paper focuses on the use of a simple one-dimensional model considering moving boundary vapor diffusion to describe the ultrasonic assisted atmospheric freeze-drying of foodstuffs. The case study is the drying of apple cubes (8.8 mm) at different air velocities (1, 2, 4 and 6 m/s), temperatures (−5, −10 and −15 °C), without and with (25, 50 and 75 W) power ultrasound application. By fitting the proposed diffusion model to the experimental drying kinetics, the effective diffusivity of water vapor in the dried product was estimated. The model was successfully validated by drying apple samples of different size and geometry (cubes and cylinders). Finally, a 23 factorial design of experiments revealed that the most relevant operating parameter affecting the drying time was the applied ultrasound power level.
Defect and Diffusion Forum, 2008
Microbial Inactivation by Ultrasound Assisted Supercritical Fluids
Physics Procedia, 2015
Temperature influence on the sugar extraction from carob pods
Experiments on the extraction of sugar from carob pods have been carried out at 20, 30, 40 and 50... more Experiments on the extraction of sugar from carob pods have been carried out at 20, 30, 40 and 50 °C respectively, in order to study the temperature effect on the extraction rate. Particle size of the ground pods was between 0.5 and 1 cm. From experimental data and considering only the period where the mass transfer (sugars) occurs by diffusion, a characteristic kinetic equation for this period has been established.
La investigación de los principales efectos de la energía ultrasónica sobre la calidad final de l... more La investigación de los principales efectos de la energía ultrasónica sobre la calidad final de los alimentos deshidratados es básica para evaluar las posibles aplicaciones de esta técnica en la industria alimentaria. El principal objetivo de este estudio fue observar la influencia de los ultrasonidos de baja frecuencia sobre la estructura celular de la patata (Solanum tuberosum L.) deshidratada. Para ello, las muestras de patata de forma cilíndrica (14 mm de diámetro y 4 mm de espesor) fueron secadas utilizando diferentes condiciones: (A) secado convencional con aire, a 19ºC y 68% de humedad relativa, (B) secado aplicando presión estática y succión, a 19ºC y 50% HR, (C) secado aplicando presión, succión y energía ultrasónica (100 W, 20,8 kHz), a 18ºC y 37% HR. En todas las experiencias la velocidad del aire fue de 1,5 m/s. El secado convencional (A) causó una mínima degradación del almidón y las paredes celulares se mantuvieron en buen estado, probablemente debido a la baja temperatura utilizada. Cuando se aplicó presión y succión durante el proceso de secado (B) se pudo observar una degradación importante del almidón, junto a un gran deterioro de las paredes celulares. Dada la relación existente entre la textura y las paredes celulares, las modificaciones observadas pueden ser responsables de la pérdida de calidad de las muestras de patata deshidratadas bajo estas condiciones. En cambio, las muestras de patata deshidratada obtenidas mediante aplicación de energía ultrasónica (C) fueron las que presentaron un mejor aspecto. De hecho, no se detectó deterioro alguno ni del almidón ni de la estructura de las paredes celulares. Por tanto, los resultados obtenidos sugieren la posibilidad de aplicar energía ultrasónica para optimizar la calidad de alimentos deshidratados como en el caso de la patata. No obstante, se necesita una evaluación más exhaustiva tanto de las propiedades texturales como de la capacidad de rehidratación de los productos deshidratados, que permita evaluar de forma más objetiva la posibilidad de implantar de esta nueva técnica en el campo de la alimentación.
A diffusion approach to describe hot air and atmospheric freeze drying kinetics of different products
The main aim of this work was to test a diffusion model to describe atmospheric freeze drying (AF... more The main aim of this work was to test a diffusion model to describe atmospheric freeze drying (AFD) and hot air drying (HAD) kinetics of different products. HAD (50 ºC and 2 ms-1) and AFD (-14 ºC, 2 ms-1) experiments were carried out for eggplant, apple and carrot cubes (side 10 mm). Kinetics were described using a diffusion model neglecting the external resistance to water transfer and the shrinkage of the samples. A good fit was obtained for AFD of apple and carrot, where assumptions considered in the model formulation were properly chosen.
The application of power ultrasound could constitute a way to improve traditional convective dryi... more The application of power ultrasound could constitute a way to improve traditional convective drying systems. There still exists a lack of knowledge on this technology in order to address industrial applications. The aim of this work was to identify the influence of the textural properties of different vegetable products on the ultrasonic assisted convective drying. For that purpose, experimental drying kinetics (40 ºC and 1 m/s) of different vegetable products (orange and lemon peel, carrot, potato and eggplant) were carried out applying different ultrasonic powers (0, 6, 12, 18, 25, 30 and 37 kW/m3). In every product, a similar diffusion model was used to identify an average effective diffusivity for the different ultrasonic powers. Product’s textural properties were assessed by Textural Profile Analysis (TPA). Linear relationships were established between the identified effective diffusivity and the applied ultrasonic power for the different products. The positive slopes of the li...
Quality assessment of dried eggplant using different drying methods: hot air drying, vacuum freeze drying and atmospheric freeze drying
Dehydration constitutes a traditional preservation method for fruits and vegetables and it repres... more Dehydration constitutes a traditional preservation method for fruits and vegetables and it represents a very important operation in food processing. The way how water is removed from food affects the final product quality, thus the characteristics of dried products are dependent on the drying technique used. The main objective of the present study was to evaluate the effect of different drying techniques on the quality of dried eggplant. For this purpose, cubic samples (10 mm side) were obtained from the flesh of Spanish origin eggplants (Solanum melongena var. Black Enorma). Three different drying techniques were applied: hot air drying (HAD, 50 ºC and 2 m/s), atmospheric freeze drying (AFD, -14 ºC and 2 m/s) and vacuum freeze drying (VFD). The drying kinetics of HAD and AFD were determined by weighing the samples at preset times during the process. To evaluate the influence of drying method on the final quality of the product, rehydration kinetics of HAD, AFD and VFD samples were ...
There is an increasing interest in process intensification by introducting alternative techniques... more There is an increasing interest in process intensification by introducting alternative techniques. This is the case of conventional drying process, usually characterized by large processing time with high energy demand and influence on the final quality of the products. The application of ultrasound could contribute to reduce the drying time when mild conditions (low air velocity and temperature) have to be applied to preserve the final quality. Ultrasound application reduces both the external and internal resistance to mass transfer, that could contribute to reduce operating and energy costs and increase the productivity.
Experiencia de laboratorio: estudio del comportamiento dinámico de un termopar. Influencia de la velocidad del fluido
Intermittent drying technology implements varying-time operating conditions to improve process en... more Intermittent drying technology implements varying-time operating conditions to improve process energy efficiency in comparison with other conventional convective drying techniques. One method of intermittent drying involves heating and resting periods. In heating periods, hot air removes the moisture and increases the material temperature by forced convection. In resting (or tempering) periods, the change of the temperature and moisture content takes place without heat supply by free convection. The mass transfer phenomena that take place during resting period may be modified by power ultrasound application. External resistance to mass transfer may be affected by pressure variations, oscillating velocities and microstreaming at the solid-gas interfaces. Internal resistance may be reduced by alternating expansion and compression cycles produced by ultrasound in the material and also through some effects on the interfaces of intercellular spaces, which may contribute to faster water d...
The final composition of cheese products constitutes one of their quality attributes and its know... more The final composition of cheese products constitutes one of their quality attributes and its knowledge in quality control is important. The measurement of ultrasonic velocity is a non-destructive technique, which allows the determination of foodstuff composition. Ultrasonic velocities in both cheese analogues and commercial cheese spreads were determined at different temperatures. The protein, fat and moisture contents of the samples ranged between 8.54 and 12.1 % (wb), 0.2 and 30.1 % (wb) and 57.5 and 81 % (wb), respectively. At 18ºC the ultrasonic velocity was not dependent on the cheese composition. The ultrasound velocity increased with the increase of fat content at temperatures lower than 18ºC and decreased for higher temperatures. From ultrasonic velocity measurements on cheese analogues, a model was developed to correlate the ultrasonic velocity, temperature and composition. This model allowed a good assessment of the composition of independent samples of cheese spreads.
Journal of Food Engineering, 2015
ABSTRACT The daily challenge involved in operating a process is the attainment of the objectives.... more ABSTRACT The daily challenge involved in operating a process is the attainment of the objectives. Process management requires the use of tools adapted to the system’s complexity. In order to obtain real time results, simplified mechanistic modelling offers a way to deal with this. To this end, carob pod (Ceratonia Siliqua, L.) kibbles extraction is addressed in this work. They are a source of different, valuable components and have a complex structure and a highly variable concentration of components. The components considered are sugars and soluble polyphenols. Obtaining the extracts with an optimal composition of a particular component, while avoiding or limiting other components in the extract, is a challenge to be addressed. Two steps can be considered: solubilization and diffusion, modelled by means of a first order reaction and by considering slab geometry. The optimal processing time and temperature are obtained by taking a particular kibble size and composition into account.