Applications of FTIR and chemometrics methods in authenticity analysis of walnut oil

• Published in: Emergent materials (Online) 2022-02, Vol.5 (1), p.167-174
• Main Authors: El Mouftari, M., Essafi, I., Khalidi, A., Kzaiber, F., Ali, Gomaa A. M., Mahjoubi, F. Z., Oussama, A.
• Format: Article
• Language: English
• Subjects: Chemistry and Materials Science; Energy Materials; Materials Engineering; Materials Science; Original Article
• ISSN: 2522-5731; 2522-574X
• DOI: 10.1007/s42247-022-00351-5

This study focuses on detecting and evaluating the adulteration in nut oil, which can cause health and food dangers. The two adulterants used during this study are cheaper vegetable oils and present a similar property with walnut oil, sunflower oil with a falsification percentage of 5.80–31.95%, and rapeseed oil with 4.33–29.37%. This adulteration was studied using Fourier transform infrared spectroscopy (FTIR) coupled with chemometrics, a new and specific approach. The spectra of the studied samples were determined by FTIR and were thermometrically analyzed by PLSR and PCR with two sorts of pretreatment, normalization, and first derivation. The results showed different functional groups of the nut oil. The most appropriate pretreatment that provides reliable calibration values (RMSE) and prediction (RMSEP) is the normalization preprocessing in the range of 3050 to 700 cm −1 . The chemometrics results give the best model selected in the PLSR with an R 2 of 0.998 for sunflower oil and 0.999 for rapeseed oil. According to this study, we have solved nut oil falsification by developing a chemometrics model that can detect and evaluate this adulteration.