title: Development of methodology for identification the nature of the polyphenolic extracts by FTIR associated with multivariate analysis.
abstract: Tannins are polyphenolic compounds of complex structures formed by secondary metabolism in several plants. These polyphenolic compounds have different applications, such as drugs, anti-corrosion agents, flocculants, and tanning agents. This study analyses six different type of polyphenolic extracts by Fourier transform infrared spectroscopy (FTIR) combined with multivariate analysis. Through both principal component analysis (PCA) and hierarchical cluster analysis (HCA), we observed well-defined separation between condensed (quebracho and black wattle) and hydrolysable (valonea, chestnut, myrobalan, and tara) tannins. For hydrolysable tannins, it was also possible to observe the formation of two different subgroups between samples of chestnut and valonea and between samples of tara and myrobalan. Among all samples analysed, the chestnut and valonea showed the greatest similarity, indicating that these extracts contain equivalent chemical compositions and structure and, therefore, similar properties.
authors: Departamento de Controle da Qualidade, Tanac S/A, Montenegro, RS, Brazil; Programa de Pós-graduação em Engenharia e Tecnologia de Materiais, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil. Electronic address: fsgrasel@gmail.com.
authors: Fábio dos Santos
authors: Fdos S
authors: Grasel
authors: Instituto de Química, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors: Marco Flôres
authors: MF
authors: Ferrão
authors: Departamento de Controle da Qualidade, Tanac S/A, Montenegro, RS, Brazil.
authors: Carlos Rodolfo
authors: CR
authors: Wolf
mesh_terms: D016000:Cluster Analysis; D047348:Hydrolyzable Tannins / Q000737:chemistry; D015999:Multivariate Analysis; D010936:Plant Extracts / Q000737:chemistry*; D059808:Polyphenols / Q000032:analysis* / Q000737:chemistry; D025341:Principal Component Analysis; D044945:Proanthocyanidins / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*
chemical_list: D047348:Hydrolyzable Tannins; D010936:Plant Extracts; D059808:Polyphenols; D044945:Proanthocyanidins
keywords: FTIR; Multivariate analysis; Polyphenolic extracts; Tannins