Extração e purificação de antocianina utilizando sistemas aquosos bifásicos

• Ano de defesa: 2012
• Autor(a) principal: Patrício, Pamela da Rocha
• Orientador(a): Silva, Maria do Carmo Hespanhol da
• Banca de defesa: Stringheta, Paulo César , Ferreira, Sukarno Olavo
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Agroquímica
• Departamento: Agroquímica analítica; Agroquímica inorgânica e Físico-química; Agroquímica orgânica
• País: BR
• Palavras-chave em Português: Sistemas aquosos bifásicos; Antocianinas; Purificação
• Palavras-chave em Inglês: Aqueous two-phase systems; Anthocyanins; Purification
• Área do conhecimento CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ANALITICA
• Link de acesso: http://locus.ufv.br/handle/123456789/2136

Anthocyanins have been highlighted as a natural colorant in food and cosmetic industries. Furthermore, regular consumption of anthocyanins is associated with probable benefits to human health attracting interest in the pharmaceutical industry. The techniques used to obtain this dye involve the co-extraction of unwanted substances which may compromise its quality, so, it is essential one step of purification of these compounds prior to their application. A common manner to purify them is through the liquid-liquid extraction that uses organics solvents that can be harmful to humans and the environment. A promising alternative environmentally safe to replace this technique are the aqueous two-phase systems (ATPS). They are composed mainly by water and the others components are nontoxic, biodegradable and inexpensive. The studied systems were formed by mixing a polymer solution (PEO1500, PEO10000, PEO35000 or PPO400) and an electrolyte solution (Li2SO4, Na2SO4, MgSO4 or (NH4)2SO4) at specific thermodynamic conditions of temperature, pressure and composition. In this study the partition behavior of the natural dye anthocyanin in several ATPS was investigated to elucidate the factors that govern the partition and propose a new method of purification of the colorant. So, the effect of tie-line length (TLL), nature of the electrolyte, molar mass and hydrophobicity of the polymer on the partition coefficients of the anthocyanins (KA) were examined. It was verified that the phenomenon of partitioning is dependent of TLL values, electrolyte nature and hydrophobicity of the polymer. The system composed of Li2SO4 and Na2SO4 were not affected by the variation of polymer molar mass. The KA values ranged from 1.1 to 89.2, indicating that the dye molecules are preferentially concentrated in the polymer-rich phase. The dyetransfer process, was spontaneous for all studied systems (&#916;trans G < 0) due a balance of enthalpic and entropic contributions.