Partição de antocianinas do açaí por meio de sistemas aquosos bifásicos

• Ano de defesa: 2018
• Autor(a) principal: Siqueira, Ana Cristina de Abreu
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Engenharia química; Açaí; Etanol; Sulfato de amônio; Polyetylene glycol; Ethanol; Ammonium sulfate
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/34462

Acai is widely consumed in Brazil because it has antioxidant activity, as it is rich in anthocyanins, which is a group of natural pigments of greater distribution in the vegetable kingdom. Aqueous Two-phase Systems (ATPS) are used for the partitioning of biomolecules, such as anthocyanins. ATPS are formed when the components of a system are immiscible and form two liquid phases at certain concentrations. The aim of this work is to partition anthocyanins of açai by ATPS. ATPS formed by PEG and ammonium sulfate, magnesium sulfate and sodium sulfate were evaluated to select the best salt for partition of anthocyanins and ammonium sulfate was the most appropriate because it had the highest yield of sugar in the salt rich phase (bottom), which was 44.56% w/w, which was then chosen to study the effect of the molar mass of PEG on the partition. PEG 8000 was chosen from PEG 4000, 6000, 8000 and 10000 because it showed higher yield of sugars in the bottom phase. All ATPS formed by PEG and salt showed 100% w/w of anthocyanins in the PEG rich phase (top phase). Among the ATPS formed by alcohols (ethanol, 1-propanol and 2-propanol) and ammonium sulfate, ethanol and ammonium sulphate showed a yield of 64.83% w/w of anthocyanins in the ethanol rich phase (top phase) and 66.17% w/w yield of sugars in the ammonium sulfate rich phase (bottom phase) against ATPS formed by 1-propanol and 2-propanol, which the anthocyanins and sugars partitioned into the bottom phase. In order to evaluate the effect of the concentration of the phase-forming components, a DCCR (Compound Rotational Central Compound Design) statistical design was carried out, whose independent variables were ethanol and ammonium sulfate concentration. The best result was with ATPS formed with 17.5% w/w of ammonium sulphate and 28% w/w of ethanol. Multistage extraction showed that one stage for ATPS PEG/ammonium sulfate and two stages for ATPS ethanol/ammonium sulfate are sufficient to remove more than 97% of the sugars for both systems. Scale-up was considered feasible for both systems, since their yields of sugars remained similar to those found in the partition realized in equilibrium cell. Anthocyanins were identified by means of UPLC-QToF.