Analysis of Black Cumin Oil Adulteration Using a Combination of UV-Vis Spectrophotometry and Chemometric Methods

Abstract

Black cumin oil is a vegetable oil known for its health benefits, but its high price makes it susceptible to adulteration. To address this issue, a combination of UV-vis spectrophotometric and chemometric methods was developed to distinguish black cumin oil from other oils. This research specifically aims to evaluate the effectiveness of UV-vis spectrophotometry and principal component analysis (PCA) and  hierarchical cluster analysis (HCA) in differentiating black cumin oil from corn and soybean oil. Samples were analyzed for absorption across a wavelength range of 220-290 nm. The UV-vis spectral data was subsequently processed using PCA and HCA to classify the samples. The results indicate that the PCA model effectively differentiates between black cumin, corn, and soybean oils. Minitab software yielded the most significant PCA results, showing a data variation distribution of 85.7% for Principal Component 1 and 10% for Principal Component 2. Furthermore, the HCA analysis corroborated the PCA findings, revealing similar sample groupings. The dendrogram produced by Minitab showcased the most distinct sample groupings. Overall, the combination of UV-vis spectrophotometry and PCA can effectively differentiate black cumin oil from corn and soybean oil.