Juan José Mangas Alonso

Servicio Regional de Investigación y Desarrollo Agroalimentario, Asturias, Spain

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Publications (4)17.23 Total impact

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    ABSTRACT: A high-speed gas chromatography method has been developed to separate the fatty acids in different milk fat fractions obtained via the dry fractionation deodorization process (TIRTIAUX method). Exploratory data techniques, namely cluster analysis and principal component analysis (PCA), were applied to gas chromatographic data for fatty acids composition in these milk fractions. Cluster analysis allowed the authors to visualize natural groupings corresponding to milk fat cracking achieved via the TIRTIAUX method. Principal component plots showed that six fractions are grouped in different classes, each group being clearly distinguished. Furthermore, a relationship was established between these classes and fatty acids through PCA analysis. A discriminant linear model for predicting milk fat classes from fatty acid composition was computed; 99 % of the criterion variable (milk fat class) variance was explained by the constructed model. Enrichment in unsaturated cis-fatty acids in the olein fractions and in the saturated and unsaturated trans-fatty acids in the stearin fractions was visualized from chemometric analysis. This differentiation of the milk fat fractions on the basis of fatty acids composition will enable food industries to use these fractions in both an efficient and safe way to enrich dairy products, or other foods, for healthy consumption.
    Food and Bioprocess Technology 01/2013; · 4.12 Impact Factor
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    ABSTRACT: In this work, a novel, simple and fast method based on solid-phase microextraction (SPME) followed by high-speed gas chromatography (HSGC) was developed for the analysis of total 1,3-octanediols in apple juices by means of derivatization reaction to volatile 1,3-dioxanes. The derivatization reaction, SPME conditions, glycosidically bound fraction and 1,3-nonanediol as a surrogate standard were studied. The formation of 1,3-dioxanes from 1,3-diols was confirmed by GC-MS. The method was validated obtaining a regression coefficient (r(2)) of 0.9996, precisions between 0.3 and 9.8%, extraction recoveries in the range 94.7-112.2% and LOD of 2.9 microg l(-1). Experimental design has been employed in the optimization of extraction factors and robustness assessment. The method was applied to the analysis of 21 Asturian apple varieties finding a double reciprocal relationship between the concentrations of saturated and unsaturated 1,3-octanediol.
    Journal of Chromatography A 03/2010; 1217(18):2993-9. · 4.61 Impact Factor
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    Domingo Blanco Gomis, Natalia Fraga Palomino, Juan José Mangas Alonso
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    ABSTRACT: Capillary liquid chromatography (CLC) is evaluated as an alternative to conventional HPLC to analyse complex phenolics. Several neutral phenolic compounds were separated on a packed-reversed phase fused-silica capillary column, and determined with UV detection. A conventional liquid chromatographic equipment was adapted for such purposes. Application of the proposed method to the quantification of neutral phenols in apple juices is reported. Phenolics are extracted and fractionated into neutral and acidic compounds by means of a C18 solid-phase cartridge. Typical recoveries ranging from 90 to 105% are obtained and reproducibility between extractions is <7% in all cases. Mass detection limits are at the sub-nanogram level.
    Analytica Chimica Acta 01/2001; · 4.39 Impact Factor
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    ABSTRACT: Headspace solid-phase microextraction coupled to Fast gas chromatography (GC) with flame ionization detector and with quadrupole mass spectrometric detector was employed to study the volatile compounds in Asturian cider apples. The best conditions used for volatile analysis of apple were: sample equilibration at 25 °C for 60 min, followed by polydimethylsiloxane-divinylbenzene fiber exposure to the headspace above the sample for 5 min, and finally thermal desorption of the adsorbed substances in the injector port for GC analysis. The use of Fast gas chromatography allowed the separation of 24 compounds in less than 8 min, reducing the analysis time in 80% compared with conventional gas chromatography. The aromatic profile of 26 crushed apple samples included in Designation of Origin Cider from Asturias was analyzed. The chemometric technique named multiple linear regression allowed us to establish a relationship between apple volatile compounds and the starch index. The results obtained are consistent with the known apple ripening model.
    Food and Bioprocess Technology · 4.12 Impact Factor