Screening method for determination of C18:1 trans fatty acids positional isomers in chocolate by H-1 NMR and chemometrics

Author(s)

Amorim, Tatiane Lima ^{[1, 2]} ; Duarte, Lucas Mattos ^{[1, 3]} ; Granato, Alisson Silva ^[4] ; Oliveira, Marcone Augusto Leal de ^[1] ; Amarante, Giovanni Wilson ^[4] ; Fuente, Miguel Angel de la ^[2] ; Gomez-Cortes, Pilar ^[2]

Affiliation

^[1] Univ Fed Juiz de Fora, Grp Quim Analit & Quimiometria GQAQ, BR-36036900 Juiz De Fora, MG - Brazil

^[2] Univ Autonoma Madrid, CSIC, Inst Invest Ciencias Alimentac CIAL, Nicolas Cabrera 9, Madrid 28049 - Spain

^[3] Univ Fed Fluminense, Inst Quim, Dept Quim Analit, BR-24020141 Niteroi, RJ - Brazil

^[4] Univ Fed Juiz De Fora, Grp Pesquisas Metodol Sintet GPMS, BR-36036900 Juiz De Fora, MG - Brazil

• Document type: Journal article
• Source: LWT-FOOD SCIENCE AND TECHNOLOGY; v. 131, SEP 2020.
• Web of Science Citations: 1

Abstract

The regulations established worldwide, restricting trans fatty acids (TFA) from industrial origin in foods, encourage the development of rapid methods to verify the quality of food products. A simple and rapid procedure based on H-1 NMR combined with multivariate calibration was developed to quantify C18:1 TFA isomers in chocolate fat. Thirty chocolate samples (milk, dark and white chocolates) were analyzed by H-1 NMR, and also by a reference gas chromatographic method. Then, partial least squares regression was used for model development. The most important H-1 NMR signals for the modeling comprised the 5.25-5.45 ppm region, corresponding to CH (double bonds and glycerol backbone), and the 1.94-1.99 ppm region, characteristic of CH2 allylic to trans double bonds. Good predictive qualities for all TFA isomers were obtained. Coefficient of correlation for prediction was 0.967 for C18:1 trans 6-8; 0.981 for C18:1 trans 9; 0.987 for C18:1 trans 10; 0.941 for C18:1 trans 11; 0.983 for C18:1 trans 12 and 0.977 for total TFA. This study demonstrates the potential of H-1 NMR to be applied in food industries in order to perform TFA control analysis as well as to investigate food fraud. (AU)

• FAPESP's process: 14/50867-3 - INCT 2014: National Institute of Science and Technology in Bioanalysis
• Grantee: Marco Aurelio Zezzi Arruda
• Support Opportunities: Research Projects - Thematic Grants