title: Polymer incompatibility as a potential tool for polyphenol recovery from olive mill wastewater.
abstract: Experiments were designed and preformed in consideration of polymer type (proteins, i.e. caseinate and ovalbumin, and polysaccharides, i.e. alginate and methylcellulose), charge character and polysaccharide concentrations, intended to understand how the polymer properties determine both phase separation and polyphenol partitioning from olive mill wastewater (OMW). The highest yield of polyphenols (YBP=92.9%) was achieved in an aqueous two-phase system (ATPS) using an ovalbumin-methylcellulose system (OMCS) in comparison to ATPS with caseinate-alginate system (CAS; YBP=85.8%) or caseinate methylcellulose system (CMCS; YBP=74%). The performance of CMCS for the ATPS partitioning of polyphenols in OMW was found to depend on the addition of salt (sodium chloride). The use of centrifugation as assistive technology appears to be necessary for the polyphenol partitioning in ATPS using OMCS. In contrast to these polymer systems, CAS caused a rapid ATPS without resorting to centrifugation and salt, mainly because of strong electrostatic repulsion between alginate and caseinate. In this regard, CAS in phase-separated OMW obtained a partition coefficient of protein (KP1) of 0.04, a tie-line length (TLL) of 10.47% (w/w) and a phase volume ratio (VR) of 0.7. Thus, ATPS based on CAS represent an efficient and environmentally friendly concept in recovery of polyphenols from OMW. The spray drying of the caseinate-polyphenol-rich phase from CAS could become a dry intermediate product with potential use in the food and non-food industry.
authors.affiliation: IEL Food Technology and Biotechnology, Department of Nutrition and Food Sciences, Rheinische Friedrich-Wilhelms-University Bonn, Roemerstrasse 164, D-53117 Bonn, Germany; German Institute of Food Technologies, Prof.-von-Klitzing-Str. 7, 49610 Quakenbrueck, Germany(1). Electronic address: f.hajji@dil-ev.de.
authors.forename: Fuad
authors.initials: F
authors.lastname: Hajji
authors.affiliation: IEL Food Technology and Biotechnology, Department of Nutrition and Food Sciences, Rheinische Friedrich-Wilhelms-University Bonn, Roemerstrasse 164, D-53117 Bonn, Germany.
authors.forename: Benno
authors.initials: B
authors.lastname: Kunz
authors.affiliation: IEL Food Technology and Biotechnology, Department of Nutrition and Food Sciences, Rheinische Friedrich-Wilhelms-University Bonn, Roemerstrasse 164, D-53117 Bonn, Germany; Symrise AG, Muehlenfeldstrasse 1, 37603 Holzminden, Germany(1).
authors.forename: Jenny
authors.initials: J
authors.lastname: Weissbrodt
mesh_terms: D000327:Adsorption; D031658:Olea / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D059808:Polyphenols / Q000737:chemistry / Q000302:isolation & purification*; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods*; D014866:Waste Products / Q000032:analysis; D062065:Wastewater / Q000737:chemistry*
chemical_list: D011108:Polymers; D059808:Polyphenols; D014866:Waste Products; D062065:Wastewater
keywords: Olive mill wastewater; Polyphenols; Polysaccharides; Protein; Thermodynamic incompatibility