Liquid-liquid equilibria in aqueous two-phase ethanol/salt systems at different temperatures and their application to anthocyanins extraction

Aqueous two-phase systems (ATPS) are formed by mixtures of chemical species that, under certain conditions, separate into two immiscible phases, with water as the major component in global terms and, at lower concentrations, polymers, salts, ionic liquids and alcohols, depending on the system type....

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Detalles Bibliográficos
Autores: Ana Clara Rocha Caldeira, Wanderley Filho Lopes de França, Attilio Converti, William James Nogueira Lima, Fábio Coelho Sampaio, Janaína Teles de Faria
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2019
País:Brasil
Institución:Universidade Federal de Minas Gerais (UFMG)
Repositorio:Repositório Institucional da UFMG
Idioma:inglés
OAI Identifier:oai:repositorio.ufmg.br:1843/43052
Acceso en línea:http://hdl.handle.net/1843/43052
Access Level:acceso abierto
Palabra clave:biphasic region
phase equilibrium
liquid-liquid extraction
Regra das fases
Equilíbrio líquido-líquido
Descripción
Sumario:Aqueous two-phase systems (ATPS) are formed by mixtures of chemical species that, under certain conditions, separate into two immiscible phases, with water as the major component in global terms and, at lower concentrations, polymers, salts, ionic liquids and alcohols, depending on the system type. Different parameters influence ATPS equilibrium such as temperature, alcohol carbon chain size, salt type, pH, etc. The present work aimed to obtain the binodal curves for ATPS made up of ethanol, sodium citrate/ammonium sulfate and water at different temperatures (15, 25 and 35 °C) as well as to evaluate the potential of the ethanol/ammonium sulfate system in anthocyanins partition. The results showed that the increase in temperature did not alter the biphasic region in the temperature range investigated, not influencing the formation of phases. Nonlinear equations were satisfactorily fitted to binodal curves data, except for sodium citrate-containing ATPS at 15 °C. Higher concentration of the overall mixture resulted in longer tie-line of ammonium sulphate-containing ATPS. Higher values of partition coefficient and recovery yield of Syzygium cumini fruit anthocyanins were obtained at longer tie-lines.