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Subject: search.filters.subject.Aqueous two-phase extraction

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    Phase demixing studies in aqueous two-phase system with polyethylene Glycol (PEG) and sodium citrate
    (2013) Nagaraja, V.H.; Iyyaswami, I.
    The kinetics of phase demixing in an aqueous two-phase system (ATPS) consisting of PEG/sodium citrate, with various PEG molecular weights (2000, 4000, and 6000) was investigated at 25°C. The rate of demixing of the phases (top/bottom) is essential to scale up the aqueous two-phase extraction (ATPE) process. The individual phase physical properties like density, viscosity, and interfacial tension are highly dynamic with the phase composition, and are responsible for the demixing of phases. Hence, in the present study, the variation of physical properties with phase compositions in terms of tie line length (TLL) was considered for the analysis of the rate of demixing of phases. The effect of the volume ratio of the phases (top/bottom) on the kinetics of phase separation also studied since the dispersed phase holdup in the mixture influences the rate of demixing. The higher TLL with a salt-rich phase as continuous phase showed higher reduction in demixing time when than low TLL at the volume ratio of <1. Based on the analysis, empirical correlations were proposed for top and bottom phase demixing rate in terms of Morton's number, volume ratio, and TLL. The coefficients and constants from the literature and the present correlations were estimated through regression analysis. The developed correlation predicted the demixing rate with lower AARD (±7%) for both the phases. The proposed correlation was accurate and simple in predicting the demixing rate of PEG/sodium citrate ATPS at 25°C. © 2013 Copyright Taylor and Francis Group, LLC.
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    Continuous aqueous two-phase extraction of ?-lactalbumin from whey in conventional rotating disc contactor
    (Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2016) Kalaivani, S.; Iyyaswami, I.
    The differential partitioning of ?-La to the PEG-rich phase and ?-Lg to the salt-rich phase was studied in the continuous extractor, rotating disc contactor (RDC), using polyethylene glycol (PEG) 1000–trisodium citrate system. The performance of the extractor was evaluated in terms of holdup, mass transfer coefficient, extraction efficiency, and recovery by studying the operating variables such as phase velocities and rotor speed. The process conditions for the maximum dispersed phase mass transfer coefficient and recovery of ?-La was also obtained and reported. © 2016 Taylor & Francis.
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    Aqueous two phase based selective extraction of mannose/glucose specific lectin from Indian cultivar of Pisum sativum seed
    (Elsevier B.V., 2019) Rashmi, B.S.; Iyyaswami, R.
    Pisum sativum lectin (Psl) being a high-value protein has marked its application in the biomedical and therapeutic field. Aqueous two phase extraction (ATPE) was implemented as a selective partitioning technique for the partial purification of Psl from its seeds. PEG/citrate based biodegradable aqueous two phase system (ATPS) was screened and the factors such as the type and concentration of citrate salts, molar mass and concentration of polyethylene glycol (PEG), tie line length (TLL) and additive (NaCl) concentration, pH, crude load and volume ratio were studied for the selective partition of Psl. The Psl was successfully extracted to the top phase in the ATPS formed with 18% PEG 6000/16% sodium citrate at 41.01% TLL, 2% NaCl and pH of 7.5. A volume ratio of 0.76 and a crude load of 20% showed maximum activity yield of 122.12% with the purification factor of 16.26. The subunits of Psl namely ? and ? were identified with a molecular weight of 6 and 18 kDa respectively during the purity analysis using SDS PAGE and HPLC. © 2019 Elsevier B.V.
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    Aqueous two-phase based simultaneous extraction and purification of cephalopod melanin
    (Taylor and Francis Ltd., 2025) Patrick, S.M.; Iyyaswami, R.; Belur, P.D.
    The cephalopod processing industry generates large quantities of ink sacs, an underutilized yet valuable source of eumelanin. Conventional extraction of melanin, relying on acid or alkali treatments, often leaves residual proteins and carbohydrates, requires multiple purification steps, and risks pigment integrity. This study investigated a polymer-salt-based aqueous two-phase system (ATPS) as an eco-friendly alternative for the selective extraction and purification of melanin. Screening of polyethylene glycols of varying molecular weights with inorganic salts identified the PEG 6000-K2HPO4 system as the most effective. The equilibrium characteristic of the system was assessed using Othmer-Tobias and Bancroft correlations, while the partitioning behavior of melanin was evaluated by considering the process parameters, including polymer and salt concentrations, tie-line length, volume ratio, and sample loading. Under optimal conditions (tie-line length of 53.23% (w/w), a volume ratio of 0.14, and a sample loading of 15% (w/w)), melanin recovery reached 99.1% with 95% purity in the PEG-rich phase. These results outperform conventional methods in both yield and product quality, highlighting ATPS as a sustainable and scalable strategy for valorizing cephalopod waste, with promising applications in food, pharmaceutical, and biomedicine. © 2025 Taylor & Francis Group, LLC.