title: Esterification of potato starch by a biocatalysed reaction in an ionic liquid.
abstract: In this study, potato starch was esterified with oleic acid, using 1-butyl-3-methylimidazolium chloride as a reaction medium and an immobilised lipase from Thermomyces lanuginosus as a catalyst. The degree of substitution (DS) of the products was determined by the volumetric method; and the best esterified product (with the highest DS) was determined by an elemental analysis. The effect of the reaction parameters on the DS, such as the time and the temperature, were also studied. The product with the highest DS (0.22) was found in the reaction carried out at 60 °C for 4h. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) analyses confirmed the esterification of the potato starch. Furthermore, the results of X-ray diffraction (XRD) and a scanning electron microscopy (SEM) revealed that the crystallinity and the morphology of the native potato starch was slightly changed during its partial gelatinisation in the ionic liquid, and was completely destroyed as a result of the formation of the esters. The thermal stability of the starch oleate decreased, when compared to the unmodified starch, as was indicated by a thermal gravimetric analysis (TGA).
authors.affiliation: Institute of Chemistry, Environmental Protection and Biotechnology, Faculty of Mathematics and Natural Sciences, Jan Dlugosz University in Czestochowa, 42-200 Czestochowa, Poland.
authors.forename: Arkadiusz
authors.initials: A
authors.lastname: Zarski
authors.affiliation: Institute of Chemistry, Environmental Protection and Biotechnology, Faculty of Mathematics and Natural Sciences, Jan Dlugosz University in Czestochowa, 42-200 Czestochowa, Poland; Institute of Technical Biochemistry, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, 90-924 Lodz, Poland.
authors.forename: Sylwia
authors.initials: S
authors.lastname: Ptak
authors.affiliation: Institute of Chemistry, Environmental Protection and Biotechnology, Faculty of Mathematics and Natural Sciences, Jan Dlugosz University in Czestochowa, 42-200 Czestochowa, Poland.
authors.forename: Przemyslaw
authors.initials: P
authors.lastname: Siemion
authors.affiliation: Institute of Chemistry, Environmental Protection and Biotechnology, Faculty of Mathematics and Natural Sciences, Jan Dlugosz University in Czestochowa, 42-200 Czestochowa, Poland. Electronic address: j.kapusniak@ajd.czest.pl.
authors.forename: Janusz
authors.initials: J
authors.lastname: Kapusniak
mesh_terms: D055162:Biocatalysis; D004951:Esterification; D052578:Ionic Liquids / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008855:Microscopy, Electron, Scanning; D011198:Solanum tuberosum / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013213:Starch / Q000737:chemistry*; D013696:Temperature
chemical_list: D052578:Ionic Liquids; D013213:Starch
keywords: 1-Butyl-3-methylimidazolium chloride; Esterification; Immobilised lipase; Oleic acid; Potato starch