Moisture adsorption isotherms in yellow pitahaya (selenicereusmegalanthus)

Moisture adsorption isotherms for yellow pitahaya fruits were studied at 15, 25, and 35 °C using the gravimetric method for a0.111-0.901 water activity range. Experimental values were adjusted by using the GAB, BET, Henderson, Smith, Caurie, and Peleg models.The isosteric heat of adsorption (Qst) wa...

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Detalles Bibliográficos
Autores: Ayala Aponte, Alfredo Adolfo, Serna Cock, Liliana, Rodriguez de la Pava, Gloria
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2011
País:Colombia
Institución:Universidad Nacional de Colombia
Repositorio:Repositorio UN
Idioma:español
OAI Identifier:oai:repositorio.unal.edu.co:unal/40445
Acceso en línea:https://repositorio.unal.edu.co/handle/unal/40445
http://bdigital.unal.edu.co/30542/
Access Level:acceso abierto
Palabra clave:Yellow pitahaya
adsorption isotherms
isosteric heat of adsorption
Descripción
Sumario:Moisture adsorption isotherms for yellow pitahaya fruits were studied at 15, 25, and 35 °C using the gravimetric method for a0.111-0.901 water activity range. Experimental values were adjusted by using the GAB, BET, Henderson, Smith, Caurie, and Peleg models.The isosteric heat of adsorption (Qst) was determined using the Clausius-Clapeyron equation. The results showed that yellow pitahaya fruitsexhibit type III adsorption isotherms and that the equilibrium moisture content (EMC) is temperature-dependent. For the same water activityvalue, the EMC decreased when temperature increased. The GAB model presented the best fitto the experimental values. The Qst droppedfrom 57.154 to 45.79 kJ/mol when the EMC increased from 0.05 to 0.40 g water/g dry matter, respectively. These results are important forestablishing the best storage conditions for dehydrated pitahaya fruits as well as for shelf-life prediction and the design of packaging materials.