Prediction of Fatty Acids in Chocolates with an Emphasis on C18:1 trans Fatty Acid Positional Isomers Using ATR-FTIR Associated with Multivariate Calibration

Abstract

The adverse effects of industrial trans fatty acids (TFA) consumption have prompted legislation to avoid these fats in food. This work aimed to predict C18:1 TFA isomers as well as other groups of fatty acids (saturated, monounsaturated, polyunsaturated, and total TFA) in chocolates by ATR-FTIR and partial least square regression. The quantification of fatty acids in representative samples (white, dark, and milk chocolates) was rapid (<30 s) and did not require derivatization. The optimized models showed satisfactory linear correlations when compared to a reference gas chromatographic method; coefficients of correlation for prediction ranged from 0.973 to 0.998 considering C18:1 trans isomers and from 0.965 to 0.999 considering fatty acids groups. The obtained results indicate that this straightforward procedure is suitable for chocolate analysis, providing its general lipid composition and TFA isomeric profile, which would be of great interest for quality control programs in the face of the new TFA regulations.

Discrimination of centre composition in panned chocolate goods using near infrared spectroscopy

“…Other researchers have used hyperspectral imaging to detect adulteration of chocolate powder with non-cocoa products. 11 Furthermore, NIR spectroscopy may be able to simultaneously profile the fatty acid composition 28,32 or sucrose content 18 of the chocolate layer, allowing identification of products made from lower quality chocolate.…”