RESUMO
Chemical characterisation has been carried out on 45 honey samples collected from Hatay region of Turkey. The concentrations of 17 elements were determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Ca, K, Mg and Na were the most abundant elements, with mean contents of 219.38, 446.93, 49.06 and 95.91 mg kg(-1) respectively. The trace element mean contents ranged between 0.03 and 15.07 mg kg(-1). Chemometric methods such as principal component analysis (PCA) and cluster analysis (CA) techniques were applied to classify honey according to mineral content. The first most important principal component (PC) was strongly associated with the value of Al, B, Cd and Co. CA showed eight clusters corresponding to the eight botanical origins of honey. PCA explained 75.69% of the variance with the first six PC variables. Chemometric analysis of the analytical data allowed the accurate classification of the honey samples according to origin.
Assuntos
Mel/análise , Espectrometria de Massas/métodos , Análise de Componente Principal/métodos , Oligoelementos/análise , Mel/classificação , Minerais/análise , Controle de Qualidade , TurquiaRESUMO
In the present work, microbial lipase from Thermomyces lanuginosus was immobilized by covalent binding onto olive pomace. Immobilized support material used to produce biodiesel with pomace oil and methanol. The properties of the support and immobilized derivative were evaluated by scanning electron microscopy (SEM). The maximum immobilization of T. lanuginosus was obtained as 18.67 mg/g support and the highest specific activity was 10.31 U/mg protein. The properties of immobilized lipase were studied. The effects of protein concentration, pH and buffer concentration on the immobilization and lipase activity were investigated. Biodiesel production using the immobilized lipase was realized by a three-step addition of methanol to avoid strong substrate inhibition. Under the optimized conditions, the maximum biodiesel yield was 93% at 25°C in 24h reaction. The immobilized enzyme retained its activity during the 10 repeated batch reactions.
Assuntos
Biocombustíveis , Enzimas Imobilizadas/química , Óleos/química , Soluções Tampão , Ésteres/química , Concentração de Íons de Hidrogênio , Lipase/química , Metanol/química , Microscopia Eletrônica de Varredura/métodos , Olea/metabolismo , Azeite de Oliva , Óleos de Plantas/química , Pós , Fatores de TempoRESUMO
Chemical characterisation has been carried out on 25 quarry marbles collected from Marmara, Aegean and Thrace regions of Turkey. Ten elements were determined by capillary electrophoresis (CE). Principal component analysis and cluster analysis techniques were utilised to define grouping of different marble samples. These techniques showed that the analysed marbles were differentiable mainly by provenance. Experimental conditions such as pH, applied voltage and concentration of alpha-hydroxyisobutyric acid (HIBA) were optimised to achieve the best separation of metal ions using central composite design. The optimum pH 3.7, applied voltage 15kV and concentration of HIBA 10mM were found to provide the best separation for all metal ions investigated.