Fourier Transform Near Infrared Spectroscopy as a Quality Control Tool for the Analysis of Lecithin and By‐Products During Soybean Oil Processing

Abstract

AbstractFourier transform near infrared (FT‐NIR) spectroscopy was used to analyze multiple measurement parameters in lecithin production samples and soybean oil refining by‐products. For lecithin, partial least squares (PLS) calibration models were developed for acetone insolubles, acid value and moisture and leave‐one‐out cross validation of the calibration models yielded root mean square error of cross validation (RMSECV) values of 0.37%, 0.59 (mg KOH/g) and 0.050%, respectively. An independent test set consisting of 40% of the lecithin production samples were predicted from the PLS calibration models and a root mean square error of prediction (RMSEP) of 0.41%, 0.53 (mg KOH/g) and 0.056% were obtained for acetone insolubles, acid value and moisture, respectively. Comparison of FT‐NIR predictions and corresponding reference method values of 10 lecithin samples using a two‐tailed t test showed no significant difference at the p = 0.05 level. A set of 51 samples of soybean oil refining by‐products, including acidulated soapstock, fatty acids and black oil, were used for developing PLS calibration models for measuring acid value, moisture and iodine value and leave‐one‐out cross validations for each model gave values for RMSECV of 6.59 (mg KOH/g), 0.046% and 0.42 (mg I2/g), respectively. Overall, the results of this study demonstrate the suitability of FT‐NIR spectroscopy for the routine analysis of lecithin production samples and soybean oil refining by‐products for quality control purposes.