s Graphite Separation in Sunflower Oil and a Possible Food Monitoring Sensor via Near-infrared Spectroscopy

Introduction: As a quick and non-destructive testing method, Fourier transform infrared (FTIR) spectroscopy has become more popular for identifying food adulteration, manipulation, and deception. Sunflower oil is a widely used food item that may be contaminated or even adulterated with potentially harmful chemical substances associated with health issues. Methods: In this regard, this study was carried out to examine the applicability of near- and midinfrared spectroscopy to identify modifications in the pure sunflower oil and sunflower oil dispersed with graphite. The dispersion of graphite powder in sunflower oil was achieved using the ultrasonic technique. The samples were analyzed using FTIR spectroscopy and transmission electron microscopy. Results: Changes in the FTIR signal were observed, indicating changes in the hydrogen atoms distribution within the solution. The flattened peak at 3470 cm^-1 was associated with the overtone of glyceride ester carbonyl absorption compared to pure SO. Additionally, the stretching vibration of carbonyl groups of triglyceride esters occurred as a significant absorption band at 1754 cm^-1, and the FTIR absorption at 1447 cm^-1 was absent. Transmission electron microscopy (TEM) analysis showed transparent layers of graphene sandwiched with sunflower oil with a distinct flake-like shape. Conclusion: These findings support dispersed graphite in sunflower oil to check the food quality.