title: A chemometric approach to determine the phenolic compounds in different barley samples by two different stationary phases: a comparison between C18 and pentafluorophenyl core shell columns.
abstract: Barley (Hordeum vulgare L.) is a cereal crop that has been cultivated since ancient times. However, its interest as nutritional food and as food ingredient is relatively new. Thus, in this study, the phenolic compounds of eighteen different varieties of barley (4 waxy and 14 non-waxy) grown under the same agronomic conditions in the same experimental field have been determined by HPLC-DAD-MS. Two new methodologies were developed using new generation superficially porous HPLC columns with different stationary phases: C18 and pentafluorophenyl (PFP). Twelve free phenolic compounds and eight bound phenolic compounds could be identified in barley samples in less than 22min. The study of different method parameters showed that C18 column was more suitable for the analysis of phenolic compounds of barley. Hierarchical cluster analysis (HCA) was conducted in order to assess the different ability of the two different core shell HPLC columns in the discrimination between "waxy" and "non-waxy" varieties, and only HCA of C18 column could separate waxy and non-waxy genotypes. Significant differences in the content of phenolic compounds between waxy and non-waxy samples were found, being waxy barley samples the ones which presented higher content of free and bound phenolic compounds. Once the best discriminant HPLC column was established, principal component analysis (PCA) was applied and it was able to discriminate between "waxy" and "non-waxy" varieties; however it discriminated the barley samples based only in free phenolic compounds. Because of that, partial least squares discriminant analysis (PLS-DA) and Artificial Neural Networks (ANN) were carried out. PLS-DA and ANN permitted the classification of waxy and non-waxy genotypes from both free and bound phenolic compounds.
authors: Department of Analytical Chemistry, University of Granada, c/Fuentenueva s/n, E-18071 Granada, Spain; Research and Development of Functional Food Centre (CIDAF), PTS Granada, Avda. del Conocimiento s/n, Edificio Bioregión, E-18007 Granada, Spain. Electronic address: anagomez@ugr.es.
authors: Ana María
authors: AM
authors: Gómez-Caravaca
authors: Inter-Departmental Centre for Agri-Food Industrial Research (CIRI Agroalimentare), University of Bologna, P.zza Goidanich 60, I-47521 Cesena (FC), Italy.
authors: Vito
authors: V
authors: Verardo
authors: Inter-Departmental Centre for Agri-Food Industrial Research (CIRI Agroalimentare), University of Bologna, P.zza Goidanich 60, I-47521 Cesena (FC), Italy.
authors: Annachiara
authors: A
authors: Berardinelli
authors: Dipartimento Agricoltura, Ambiente e Alimenti, Università del Molise, via De Sanctis, I-86100 Campobasso (CB), Italy; Università Campus Bio-Medico di Roma, via Álvaro del Portillo, 21, I-00128 Roma, Italy.
authors: Emanuele
authors: E
authors: Marconi
authors: Inter-Departmental Centre for Agri-Food Industrial Research (CIRI Agroalimentare), University of Bologna, P.zza Goidanich 60, I-47521 Cesena (FC), Italy; Department of Agricultural and Food Sciences, Alma Mater Studiorum-University of Bologna, Piazza Goidanich, 60, I-47521 Cesena (FC), Italy.
authors: Maria Fiorenza
authors: MF
authors: Caboni
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation* / Q000379:methods; D005464:Fluorobenzenes / Q000737:chemistry*; D001467:Hordeum / Q000737:chemistry*; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods; D010636:Phenols / Q000032:analysis* / Q000737:chemistry; D005466:Fluorocarbons
chemical_list: D005464:Fluorobenzenes; D010636:Phenols; C085539:2,3,4,5,6-pentafluorophenol; D005466:Fluorocarbons
keywords: Barley; Chemometrics; Core shell column; Phenolic compounds; Waxy and non-waxy