title: Picrocrocin kinetics in aqueous saffron spice extracts (Crocus sativus L.) upon thermal treatment.
abstract: The kinetics of picrocrocin degradation in aqueous extracts of saffron upon thermal treatment from 5 to 70 °C have been studied, together with the degradation of purified picrocrocin in water at 100 °C. The best fits to experimental data were found for a second-order kinetics model. Picrocrocin showed high stability with half-life periods (t(1/2)) ranging from >3400 h at 5 °C in saffron extracts to 9 h in the experiments with purified picrocrocin at 100 °C. In saffron extracts, the evolution of the rate constant (k) with temperature showed maximum values at 35 °C, and filtration of the extracts contributed to picrocrocin stability. In the case of purified picrocrocin, the generation of safranal in the first 5 h (yield up to 7.4%) was confirmed. Spectrometric parameters used in saffron quality control (E(1cm)(1%) 257 nm and ΔΕ(pic)) were not appropriate for documenting the evolution of picrocrocin.
authors.affiliation: Cátedra de Química Agrícola, ETSI Agrónomos de Albacete, Universidad de Castilla-La Mancha, Albacete, Spain.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Sánchez
authors.forename: Manuel
authors.initials: M
authors.lastname: Carmona
authors.forename: Manuel
authors.initials: M
authors.lastname: Jarén-Galán
authors.forename: M Isabel Mínguez
authors.initials: MI
authors.lastname: Mosquera
authors.forename: Gonzalo L
authors.initials: GL
authors.lastname: Alonso
mesh_terms: D027622:Crocus / Q000737:chemistry*; D053138:Cyclohexenes / Q000737:chemistry*; D005960:Glucosides / Q000737:chemistry*; D006358:Hot Temperature; D007700:Kinetics; D010936:Plant Extracts / Q000737:chemistry*; D013729:Terpenes / Q000737:chemistry*
chemical_list: D053138:Cyclohexenes; D005960:Glucosides; D010936:Plant Extracts; D013729:Terpenes; C087962:picrocrocin