Determination of rancidity of soybean oil by near infrared spectroscopy

摘要: The technique of near-infrared (NIR) reflectance spectroscopy was used in order to test its use as a potential method for determining the rancidity soybean oils undergoing autoxidation. Commercial oil substrate and oxidized at 75°C until reached hydroperoxide decomposition stage. Peroxide values (POVs) acid (AVs) determined by chemical were correlated with NIR spectral absorbances. Two wavelengths (2080 2020 nm) selected POV calibration, resulting coefficient multiple determination regression quite high (r = 0.9970, SEC 9.10 meq / kg SEP 9.67 oil). prediction using reference found be accurate early stages oxidation. However, it undesirable calibration equation stages. Three (2008, 1442 1752 AV calibration. High correlations achieved between chemically analyzed AVs predicted 0.9987, 0.127 mg KOH g oil, 0.137 represented good indicator thermal oxidation, whereas evaluation has proven difficult due decomposition. result this study suggested that more precise than an accumulation stages, better predictor higher ranges.