Determination of the degree of methylesterification of pectic polysaccharides by FT-IR using an outer product PLS1 regression

• Type: Article in International Scientific Journal
• Date: 2002

Authors

Barros, AS (Author) Other; Isabel Mafra (Author) Other; Ferreira, D (Author) Other; Cardoso, S (Author) Other; Reis, A (Author) Other; da Silva, JAL (Author) Other; Delgadillo, I (Author) Other; Rutledge, DN (Author) Other; Coimbra, MA (Author) Other

Journal

Title: Carbohydrate Polymers

Vol. 50

Pages: 85-94

ISSN: 0144-8617

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 77 Citations

Scopus - 82 Citations

Other information

Authenticus ID: P-000-MS3

DOI: 10.1016/s0144-8617(02)00017-6

Abstract (EN): The combination of the absorbance spectra in two infrared regions (1800-1500 and 1200-850 cm(-1)) was used to build a calibration model for the determination of the degree of methylesterification (DM) of pectic polysaccharides. The wavenumbers in the region 1800-1500 cm(-1) are related to the carbonyl esters and carboxylates and those in the region 1200-850 cm(-1) are related to the sugars composition. The model was done by means of a matrix of the outer product of the two regions and PLS1 regression, using cell wall pectic polysaccharide extracts from olive and pear pulps. The application of the Durbin-Watson criterion to the regression vector of OP-PLS1 gave an 'optimal' model with nine latent variables, with a RMSEP of 7.7% and a coefficient of determination (R-2) of 0.95. The model explained 95% of the total variability present in the y vector. The results allowed the prediction of the DM of commercial standard pectic polysaccharides and of impure pectic polysaccharide extracts. A prediction error of 22% was found, which contrasted with the prediction error of 72% when only the region 1800-1500 cm(-1) region was used.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10