Application of ATR-FTIR and chemometrics for rapid lard adulteration assessment in confectionery

Abstract

Consumption of confectionery products such as chocolates and biscuits are popular among all age groups in the population around the globe. Adulteration of confectionery fats with cheaper animal fats, such as lard, has become an issue in recent years. A simple and rapid analytical method of attenuated total reflectance in Fourier transform infrared spectroscopy (ATR-FTIR) was developed in order to determine the lard content in imported chocolates and biscuits. For quantitative measurement, the partial least square (PLS) model with multivariate calibration for adulterant prediction was developed. A lard oil calibration graph was drawn (2–35 %) with palm oil in the region of 3035–2984 cm⁻¹, with the correlation coefficient (R²) = 0.9994 with minimum errors in root mean square error of calibration (RMSEC) and root mean square error of prediction (RMSEP) with the value of 0.320 and 0.315 respectively. The root mean square error of cross-validation (RMSECV) was used to find the calibration model accuracy which was found to be 1.17 with the best limit of detection (LOD) 0.10 % and limit of quantification (LOQ) 0.35 %. The developed ATR-FTIR method is robust accurate and precise in terms of lard detection in confectionery products (chocolate and biscuits).