Authentication of lotus root powder adulterated with potato starch and/or sweet potato starch using Fourier transform mid-infrared spectroscopy

Fourier transform mid infrared (FT-MIR) spectroscopy combined with chemometrics techniques were developed for classification and quantification of cheaper starches (potato and sweet potato starch) in lotus root powder (LRP). By performing principal component analysis (PCA), it was possible to distinguish between adulterated and non-adulterated LRP. The coefficient of determination (R2) and standard deviation ratio (SDR) of calibration set were found to be 0.9587–0.9898 and 3.63–10.2, depending on the pre-treatment of spectra. The external validation set gave a coefficient of determination (R2) and standard deviation ratio (SDR) of 0.9810 and 5.47, respectively. Moreover, the limit of detection (1%), the limit of quantification (3%), reasonable recovery (92.3–101.5%), satisfactory intra-assay (2.9–5.5%) and inter-assay (11.0–13.5%) precision illustrated the good performance of the present method. The results obtained in this study indicate that FT-MIR spectroscopy can be used as an easy, rapid and novel tool to detect the LRP adulterated with cheaper starches.