title: Determination of the Mineral Composition and Toxic Element Contents of Propolis by Near Infrared Spectroscopy.
abstract: The potential of near infrared spectroscopy (NIR) with remote reflectance fiber-optic probes for determining the mineral composition of propolis was evaluated. This technology allows direct measurements without prior sample treatment. Ninety one samples of propolis were collected in Chile (Bio-Bio region) and Spain (Castilla-León and Galicia regions). The minerals measured were aluminum, calcium, iron, potassium, magnesium, phosphorus, and some potentially toxic trace elements such as zinc, chromium, nickel, copper and lead. The modified partial least squares (MPLS) regression method was used to develop the NIR calibration model. The determination coefficient (R2) and root mean square error of prediction (RMSEP) obtained for aluminum (0.79, 53), calcium (0.83, 94), iron (0.69, 134) potassium (0.95, 117), magnesium (0.70, 99), phosphorus (0.94, 24) zinc (0.87, 10) chromium (0.48, 0.6) nickel (0.52, 0.7) copper (0.64, 0.9) and lead (0.70, 2) in ppm. The results demonstrated that the capacity for prediction can be considered good for wide ranges of potassium, phosphorus and zinc concentrations, and acceptable for aluminum, calcium, magnesium, iron and lead. This indicated that the NIR method is comparable to chemical methods. The method is of interest in the rapid prediction of potentially toxic elements in propolis before consumption.
authors.affiliation: Departamento de Química Analítica, Nutrición y Bromatología. Facultad de Ciencias Químicas, Universidad C/ Plaza de los Caidos s/n. Salamanca 37008, Spain. inmaglez@usal.es.
authors.forename: M Inmaculada
authors.initials: MI
authors.lastname: González-Martín
authors.affiliation: Departamento BiologíaVegetal y Ciencias del Suelo. Facultad de Ciencias, Universidad de Vigo, As Lagoas, Ourense 32004, Spain. oescuredo@uvigo.es.
authors.forename: Olga
authors.initials: O
authors.lastname: Escuredo
authors.affiliation: Tecnología de los Alimentos, Escuela Politécnica Superior de Zamora, Avda Requejo 33, Zamora 49022, Spain. irevilla@usal.es.
authors.forename: Isabel
authors.initials: I
authors.lastname: Revilla
authors.affiliation: Tecnología de los Alimentos, Escuela Politécnica Superior de Zamora, Avda Requejo 33, Zamora 49022, Spain. avivar@usal.es.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Vivar-Quintana
authors.affiliation: Departamento BiologíaVegetal y Ciencias del Suelo. Facultad de Ciencias, Universidad de Vigo, As Lagoas, Ourense 32004, Spain. mcoello@uvigo.es.
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Coello
authors.affiliation: Producción Animal, Facultad de Ciencias Agrarias y Ambientales, Universidad. Avda, Filiberto Villalobos, Salamanca 119-129, Spain. carlospalacios@colvet.es.
authors.forename: Carlos Palacios
authors.initials: CP
authors.lastname: Riocerezo
authors.affiliation: Departamento de Producción Animal, Facultad de Agronomía, Universidad de Concepción, Avda. Vicente Méndez, 595 Chillán, Chile. guillermo.wells.moncada@gmail.com.
authors.forename: Guillermo Wells
authors.initials: GW
authors.lastname: Moncada
mesh_terms: D004867:Equipment Design; D016018:Least-Squares Analysis; D008670:Metals / Q000032:analysis*; D008903:Minerals / Q000032:analysis*; D011429:Propolis / Q000032:analysis / Q000737:chemistry / Q000145:classification; D019265:Spectroscopy, Near-Infrared / Q000379:methods*
chemical_list: D008670:Metals; D008903:Minerals; D011429:Propolis
keywords: cross-validation; determination; lead; mineral composition; near-infrared spectroscopy; propolis