title: Hydrothermal Degradation of Rutin: Identification of Degradation Products and Kinetics Study.
abstract: The model glycoside compound quercetin-3-O-rutinoside (rutin) was subjected to subcritical water within the temperature range of 120-220 °C, and the hydrothermal degradation products were analyzed. Two kinetic models describing the degradation of this compound in two different atmospheres (N2and CO2), used for pressure establishment in the reactor, have been developed and compared. Reaction was considered a successive one with three irreversible steps. We confirmed that rutin degradation to quercetin follows first-order kinetics. At higher temperatures quercetin is further degraded in two degradation steps. Formations of 3,4-dihydroxybenzoic acid and catechol were described with the zero-order kinetic models. Reaction rate constants for hydrolysis of glycoside to aglycone in a CO2atmosphere are higher compared to those in a N2atmosphere, whereas at higher temperatures reaction rate constants for further two successive reactions of aglycone degradation are slightly lower in the presence of CO2. The difference in reaction activation energies is practically negligible for both gases. Furthermore, degradation products of sugar moieties, that is, 5-hydroxymethylfurfural and 5-methylfurfural, were also detected and analyzed.
authors.affiliation: Faculty of Chemistry and Chemical Engineering, University of Maribor , Smetanova 17, SI-2000 Maribor, Slovenia.
authors.forename: Matej
authors.initials: M
authors.lastname: Ravber
authors.affiliation: Faculty of Chemistry and Chemical Engineering, University of Maribor , Smetanova 17, SI-2000 Maribor, Slovenia.
authors.forename: Darja
authors.initials: D
authors.lastname: Pečar
authors.affiliation: Faculty of Chemistry and Chemical Engineering, University of Maribor , Smetanova 17, SI-2000 Maribor, Slovenia.
authors.forename: Andreja
authors.initials: A
authors.lastname: Goršek
authors.affiliation: Faculty of Chemistry and Chemical Engineering, University of Maribor , Smetanova 17, SI-2000 Maribor, Slovenia.|Jožef Štefan Institute , Jamova 39, SI-1000 Ljubljana, Slovenia.
authors.forename: Jernej
authors.initials: J
authors.lastname: Iskra
authors.affiliation: Faculty of Chemistry and Chemical Engineering, University of Maribor , Smetanova 17, SI-2000 Maribor, Slovenia.
authors.forename: Željko
authors.initials: Ž
authors.lastname: Knez
authors.affiliation: Faculty of Chemistry and Chemical Engineering, University of Maribor , Smetanova 17, SI-2000 Maribor, Slovenia.
authors.forename: Mojca
authors.initials: M
authors.lastname: Škerget
mesh_terms: D002396:Catechols / Q000737:chemistry; D005662:Furaldehyde / Q000031:analogs & derivatives / Q000737:chemistry; D006027:Glycosides / Q000737:chemistry*; D006358:Hot Temperature; D006868:Hydrolysis; D062385:Hydroxybenzoates / Q000737:chemistry; D007700:Kinetics; D011312:Pressure; D012431:Rutin / Q000737:chemistry*; D014867:Water
chemical_list: D002396:Catechols; D006027:Glycosides; D062385:Hydroxybenzoates; D014867:Water; C009091:protocatechuic acid; C048065:5-methyl-2-furfural; D012431:Rutin; C008046:5-hydroxymethylfurfural; D005662:Furaldehyde; C034221:catechol
keywords: 5-methylfurfural; degradation; kinetics; rutin; subcritical water