title: The interaction of chitosan and olive oil: effects of degree of deacetylation and degree of polymerization.
abstract: The combined effects of degree of deacetylation (DD) and degree of polymerization (DP) on the ability of chitosan to interact with olive oil was studied. The oil-binding test, a method that makes use of olive oil as a representative fat, was adopted as a measure of the interaction of chitosan and olive oil. The oil-binding capacities of twelve chitosan samples with DPs ranging from 470 to 1450 and DDs of 75% to 95% were determined. The oil-binding capacities were then correlated to the DD and DP using partial least squares (PLS) regression. The generated PLS model had a root mean square error of prediction (RMSEP) of 9.1%. Results indicated that oil-binding capacity is a function of DD more than of DP. For chitosan with DD at the interval 50%<DD<90%, a negatively sloped linear correlation was obtained for DD and oil-binding capacity suggesting that hydrophobic intermolecular forces of attraction dominates the interaction of chitosan with olive oil. For chitosan with DD>90%, the observed deviation from the linear correlation increased. In this interval, free fatty acid anions facilitate the interaction of chitosan and olive oil. Free fatty acids form a stable ionic interaction with the former and a strong hydrophobic interaction with the latter.
authors.affiliation: Institute for Analytical Research, University of Applied Sciences Fresenius, Limburger Str. 2, 65510 Idstein, Germany. dimzon@hs-fresenius.de
authors.forename: Ian Ken D
authors.initials: IK
authors.lastname: Dimzon
authors.forename: Jürgen
authors.initials: J
authors.lastname: Ebert
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Knepper
mesh_terms: D000107:Acetylation; D048271:Chitosan / Q000138:chemical synthesis / Q000737:chemistry; D005227:Fatty Acids / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D007477:Ions / Q000737:chemistry; D000069463:Olive Oil; D010938:Plant Oils / Q000138:chemical synthesis / Q000737:chemistry; D058105:Polymerization
chemical_list: D005227:Fatty Acids; D007477:Ions; D000069463:Olive Oil; D010938:Plant Oils; D048271:Chitosan