Scientific Study

BACKGROUND: Pistachio has high economic value due to its high consumption rate and consumer demand. Therefore, it has become an important target for adulteration. Green pea and spinach are the most frequently used foods for pistachio adulteration because of their kernel color. The aim of the present study is to detect pistachio adulteration with green pea and spinach samples by using Laser Induced Breakdown Spectroscopy (LIBS) combined with chemometric methods. RESULTS: In the first step of the study, principal component analysis (PCA) was employed for qualitative analysis of pure pistachio, green pea, spinach and adulterated pistachio samples, and discrimination was achieved with successfully. A score plot clearly discriminating pure pistachio, green pea and spinach samples as well as their blind samples was drawn using principle component 1 (PC1) and principle component 2 (PC2) which explained 86.86% and 12.16% of the variance, respectively. The results showed that the calibration curve for green pea adulterated pistachio provides successful determination of adulteration level and had 0.995 of R2 and 2.04% of limit of detection (LOD) values, while the calibration curve for spinach adulterated pistachio had 0.993 of R2 and 1.64% of LOD. CONCLUSION: The results demonstrated that the LIBS with the chemometric methods showed good performance based on the high value of prediction accuracy for pistachio adulteration. This method has high potential for rapidly measurement of pistachio identification and adulteration.