title: Luminescence detection and dose assessment of irradiated Yerba Mate (Ilex paraguariensis) tea leaves.
abstract: Imported commercial samples of Yerba Mate (Ilex paraguariensis) tea leaves were characterized by thermoluminescence (TL) and photoluminescence (PSL) physical methods. Samples of Yerba Mate were irradiated between 0.5-50Gy and 20Gy-5kGy gamma doses by using two different dose rates from (60)Co irradiators. The Electron Dispersive Analysis (EDS) shows that the inorganic fraction is mainly composed by quartz and Ca-feldspars minerals. These polyminerals show a good sensitivity to gamma radiation and to UV light (530nm). Linear dose-response curves were obtained between 0.5 and 12Gy at low dose-rate, and with 20 to 500Gy at high dose-rate of gamma radiation. At higher doses (600Gy) an apparent slow saturation effect was observed. Low fading of the TL signal was found. The detection limits of TL and PSL are 6Gy and 300Gy, respectively. Results show that luminescence emission (TL and PSL) is a reliable method for detection of irradiation Yerba Mate.
authors.affiliation: Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, A. P. 70-543, 04510 México D.F., Mexico. Electronic address: ecruz@nucleares.unam.mx.
authors.forename: E
authors.initials: E
authors.lastname: Cruz-Zaragoza
authors.affiliation: Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, A. P. 70-543, 04510 México D.F., Mexico.
authors.forename: J
authors.initials: J
authors.lastname: Roman-Lopez
authors.affiliation: Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, A. P. 70-543, 04510 México D.F., Mexico.
authors.forename: D
authors.initials: D
authors.lastname: Ramos Córdoba
authors.affiliation: Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, A. P. 70-543, 04510 México D.F., Mexico.
authors.forename: C
authors.initials: C
authors.lastname: Furetta
authors.affiliation: Instituto de Física Arroyo Seco (CIFICEN-CONICET), Universidad Nacional del Centro de la Provincia de Buenos Aires, Pinto 399, 7000 Tandil, Argentina.
authors.forename: M
authors.initials: M
authors.lastname: Santiago
authors.affiliation: Instituto de Física Arroyo Seco (CIFICEN-CONICET), Universidad Nacional del Centro de la Provincia de Buenos Aires, Pinto 399, 7000 Tandil, Argentina.
authors.forename: J
authors.initials: J
authors.lastname: Marcazzó
keywords: Irradiated foodstuffs; Photoluminescence; Polyminerals; Thermoluminescence; Yerba Mate tea