title: Chitosan microbeads for encapsulation of thyme (Thymus serpyllum L.) polyphenols.
abstract: In this work chitosan microbeads were prepared by emulsion technique and loaded with thyme polyphenols by diffusion from an external aqueous solution of Thymus serpyllum L. The effects of concentrations of chitosan (1.5-3% (w/v)) and GA (glutaraldehyde) (0.1-0.4% (v/v)), as a crosslinking agent on the main properties of microbeads were assessed. The obtained microgel beads from ∼ 220 to ∼ 790 μm in diameter were exposed to controlled drying process at air (at 37 °C) after which they contracted to irregular shapes (∼ 70-230 μm). The loading of dried microbeads with polyphenols was achieved by swelling in the acidic medium. The swelling rate of microbeads decreased with the increase in GA concentration. Upon this rehydration, thyme polyphenols were effectively encapsulated (active load of 66-114 mg GAE g(beads)(-1)) and the microbeads recovered a spherical shape. Both, the increase in the amount of the crosslinking agent and the presence of polyphenols, contributed to a more pronounced surface roughness of microbeads. The release of encapsulated polyphenols in simulated gastrointestinal fluids was prolonged to 3h.
authors.affiliation: University of Belgrade - Faculty of Technology and Metallurgy, Department of Chemical Engineering, Karnegijeva 4, 11000 Belgrade, Serbia. Electronic address: ktrifkovic@tmf.bg.ac.rs.
authors.forename: Kata T
authors.initials: KT
authors.lastname: Trifković
authors.affiliation: The Academy of Criminalistic and Police Studies, Department of Forensics, Cara Dušana 196, 11080 Belgrade, Serbia. Electronic address: nikolla3@tmf.bg.ac.rs.
authors.forename: Nikola Z
authors.initials: NZ
authors.lastname: Milašinović
authors.affiliation: University of Belgrade - Faculty of Technology and Metallurgy, Department of Chemical Engineering, Karnegijeva 4, 11000 Belgrade, Serbia. Electronic address: vnedovic@agrif.bg.ac.rs.
authors.forename: Verica B
authors.initials: VB
authors.lastname: Djordjević
authors.affiliation: University of Belgrade - Faculty of Technology and Metallurgy, Department of Organic Chemical Technology, Karnegijeva 4, 11000 Belgrade, Serbia. Electronic address: meli@tmf.bg.ac.rs.
authors.forename: Melina T Kalagasidis
authors.initials: MT
authors.lastname: Krušić
authors.affiliation: University of Belgrade - Faculty of Technology and Metallurgy, Department of Biochemical Engineering and Biotechnology, Karnegijeva 4, 11000 Belgrade, Serbia. Electronic address: zknez@tmf.bg.ac.rs.
authors.forename: Zorica D
authors.initials: ZD
authors.lastname: Knežević-Jugović
authors.affiliation: University of Belgrade - Faculty of Agriculture, Department of Food Technology and Biochemistry, Nemanjina 6, 11080 Belgrade, Serbia. Electronic address: vmanojlovic@tmf.bg.ac.rs.
authors.forename: Viktor A
authors.initials: VA
authors.lastname: Nedović
authors.affiliation: University of Belgrade - Faculty of Technology and Metallurgy, Department of Chemical Engineering, Karnegijeva 4, 11000 Belgrade, Serbia. Electronic address: branko@tmf.bg.ac.rs.
authors.forename: Branko M
authors.initials: BM
authors.lastname: Bugarski
mesh_terms: D048271:Chitosan / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry; D003692:Delayed-Action Preparations / Q000737:chemistry*; D004339:Drug Compounding; D004655:Emulsions / Q000737:chemistry*; D005976:Glutaral / Q000737:chemistry; D059808:Polyphenols / Q000008:administration & dosage* / Q000737:chemistry; D046930:Thymus Plant / Q000737:chemistry*
chemical_list: D003432:Cross-Linking Reagents; D003692:Delayed-Action Preparations; D004655:Emulsions; D059808:Polyphenols; D048271:Chitosan; D005976:Glutaral
keywords: Chitosan microbeads; Emulsion crosslinking technique; Microencapsulation; Polyphenols