In this study, qualitative and quantitative analyses of peanut oils adulterated with waste oil, soybean oil, corn oil and canola oil were performed by combining near infrared (NIR) spectroscopy with chemometrics methods. With NIR spectrometer, the spectra of 108 adulterated peanut oil samples were collected. The collected data were preprocessed with three different preprocessing approaches, including standard normal variate (SNV) transformation, de-trending (DT), and orthogonal signal correction (OSC). Backward interval partial least squares (BiPLS) was used to extract the characteristic wavel...