Turmeric (Curcuma longa), is a popular spice in traditional cuisine and now is globally available. As in the case of many widespread spices, turmeric powder is often adulterated using various additives and colorants. Therefore, the identification of adulterated turmeric is of paramount importance. However, the existing methods are laborious, expensive and time-consuming. In this study, we propose a multispectral imaging system for detecting the percentage of the common adulterant; tartrazine colored rice flour found in turmeric powder. A multispectral imaging system was developed utilizing nine spectral bands with peak wavelengths from 405 nm to 950 nm. An algorithm was developed based on Principal Component Analysis (PCA) and Bhattacharyya Distance. The relationship between the Bhattacharyya Distance and the adulteration level was modeled as a second-order polynomial with an R2 = 0.9911 and the results were validated using an independent set of samples with an R2 = 0.9816.