Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/327171
Type: Artigo
Title: Time-domain Nuclear Magnetic Resonance (td-nmr) And Chemometrics For Determination Of Fat Content In Commercial Products Of Milk Powder
Author: Martins Nascimento
Paloma Andrade; Barsanelli
Paulo Lopes; Rebellato
Ana Paula; Lima Pallone
Juliana Azevedo; Colnago
Luiz Alberto; Verbi Pereira
Fabiola Manhas
Abstract: This study shows the use of time-domain (TD)-NMR transverse relaxation (T-2) data and chemometrics in the nondestructive determination of fat content for powdered food samples such as commercial dried milk products. Most proposed NMR spectroscopy methods for measuring fat content correlate free induction decay or echo intensities with the sample's mass. The need for the sample's mass limits the analytical frequency of NMR determination, because weighing the samples is an additional step in this procedure. Therefore, the method proposed here is based on a multivariate model of T-2 decay, measured with Carr-Purcell-Meiboom-Gill pulse sequence and reference values of fat content. The TD-NMR spectroscopy method shows high correlation (r = 0.95) with the lipid content, determined by the standard extraction method of Bligh and Dyer. For comparison, fat content determination was also performed using a multivariate model with near-IR (NIR) spectroscopy, which is also a nondestructive method. The advantages of the proposed TD-NMR method are that it (1) minimizes toxic residue generation, (2) performs measurements with high analytical frequency (a few seconds per analysis), and (3) does not require sample preparation (such as pelleting, needed for NIR spectroscopy analyses) or weighing the samples.
Subject: Infrared-spectroscopy
Total Protein
Lipids
Spectra
Editor: AOAC Int
Gaithersburg
Rights: fechado
Identifier DOI: 10.5740/jaoacint.16-0408
Address: http://www.ingentaconnect.com/content/aoac/jaoac/2017/00000100/00000002/art00004
Date Issue: 2017
Appears in Collections:Unicamp - Artigos e Outros Documentos

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