Improvement of water transport mechanisms during potato drying by applying ultrasound

• Published in: Journal of the science of food and agriculture Vol. 91; no. 14; pp. 2511 - 2517
• Main Authors: Ozuna, César, Cárcel, Juan A, García-Pérez, José V, Mulet, Antonio
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01-11-2011; Wiley; John Wiley and Sons, Limited
• Subjects: Biological and medical sciences; Chemical Phenomena; Convection; dehydration; Desiccation - instrumentation; Desiccation - methods; Diffusion; energy efficiency; Food engineering; Food Handling - instrumentation; Food Handling - methods; Food industries; Food preservation; Food science; Fundamental and applied biological sciences. Psychology; General aspects; Handling, storage, packaging, transport; Kinetics; Mechanical Phenomena; modelling; Models, Chemical; Plant Roots - chemistry; Potatoes; Quality Control; Solanum tuberosum - chemistry; Ultrasonics - methods; Water; Water - analysis; Water; Vegetables; Dehydration; modelling; Mechanism; Potato; Improvement; Energetic efficiency; energy efficiency; Tuber; Diffusion; Transport; Ultrasound; Drying
• ISSN: 0022-5142; 1097-0010
• DOI: 10.1002/jsfa.4344

BACKGROUND: The drying rate of vegetables is limited by internal moisture diffusion and convective transport mechanisms. The increase of drying air temperature leads to faster water mobility; however, it provokes quality loss in the product and presents a higher energy demand. Therefore, the search for new strategies to improve water mobility during convective drying constitutes a topic of relevant research. The aim of this work was to evaluate the use of power ultrasound to improve convective drying of potato and quantify the influence of the applied power in the water transport mechanisms.
RESULTS: Drying kinetics of potato cubes were increased by the ultrasonic application. The influence of power ultrasound was dependent on the ultrasonic power (from 0 to 37 kW m−3), the higher the applied power, the faster the drying kinetic. The diffusion model considering external resistance to mass transfer provided a good fit of drying kinetics. From modelling, it was observed a proportional and significant (P < 0.05) influence of the applied ultrasonic power on the identified kinetic parameters: effective moisture diffusivity and mass transfer coefficient.
CONCLUSIONS: The ultrasonic application during drying represents an interesting alternative to traditional convective drying by shortening drying time, which may involve an energy saving concerning industrial applications. In addition, the ultrasonic effect in the water transport is based on mechanical phenomena with a low heating capacity, which is highly relevant for drying heat sensitive materials and also for obtaining high‐quality dry products. Copyright © 2011 Society of Chemical Industry