Journal of Food, Agriculture and Environment

Vol 10, Issue 2,2012
Online ISSN: 1459-0263
Print ISSN: 1459-0255

Sorption isotherms of albumen dried in a spout fluidised bed


Divair Christ 1*, Rosiane Lopes da Cunha 2, Florencia Cecilia Menegalli 2, Katiuchia Pereira Takeuchi 3, Silvia Renata Machado Coelho 1, Lúcia Helena Pereira Nóbrega 1

Recieved Date: 2012-01-16, Accepted Date: 2012-04-30


Dehydrated products are characterized by low water activity and a low volume when compared to the original weight, for easy handling, storage and transportation. A study of the sorption isotherms provides the information necessary to fit the drying and packaging parameters. Thus, this trial aimed to collect sorption isotherm data for albumen dried in a spout fluidised bed, correlated by several classical mathematical models. Samples of albumen containing 3.1% moisture on a dry weight basis (d.b.), underwent adsorption at 5, 10, 15, 25, 40 and 70°C in environments with controlled water activity, ranging from 0.1 to 0.93, until reaching the equilibrium moisture content, and the experimental data was applied to the Sigma-Copace, Sabbah, Oswin, modified Henderson, modified Halsey, Copace and Smith models. It was concluded that the equations matched the experimental data well for the ranges of temperature and relative humidity studied. The Sigma-Copace model was the one that best represented the hygroscopicity of the product, with a magnitude of adjustment of 0.95, mean relative deviation of 22.98 and root mean square error of 2.41. The isosteric heat of sorption was evaluated by means of the Classius-Clapeyron equation. The Vivanco-Pezantes equation best described the behaviour of the net isosteric heat, which increased due to the lower water availability of the product. This equation presented a magnitude of adjustment of 0.98 and mean relative deviation of 4.53. The Vivanco-Pezantes model predicted the values for the isosteric heat of the albumen powder more accurately than the traditional models, and indicated that below 20% d.b., the water became more tightly bound, requiring larger amounts of energy to dry the egg white. 


Egg white, equilibrium moisture content, mathematical modelling, isosteric heat

Journal: Journal of Food, Agriculture and Environment
Year: 2012
Volume: 10
Issue: 2
Category: Food and Health
Pages: 151-155

Full text for Subscribers

Note to users

The requested document is freely available only to subscribers/registered users with an online subscription to the Journal of Food, Agriculture & Environment. If you have set up a personal subscription to this title please enter your user name and password. All abstracts are available for free.

Article purchasing

If you like to purchase this specific document such as article, review or this journal issue, contact us. Specify the title of the article or review, issue, number, volume and date of the publication. Software and compilation, Science & Technology, all rights reserved. Your use of this website details or service is governed by terms of use. Authors are invited to check from time to time news or information.

Purchase this Article:   20 Purchase PDF Order Reprints for 15

Share this article :