Crude Protein Content Determination of Potatoes by NIRS Technology

The determination of the composition of potatoes is essential in order to meet the current demand for quality products. The traditional methods to measure potato components are both expensive and laborious; therefore, some authors have studied the application of faster and cheaper techniques such as near infrared spectroscopy (NIRS) to determine those components. The objective of the present work is to predict the crude protein (CP) content of lyophilized samples of potato by NIRS.135 samples were used in this study. NIR spectral data were collected using an AOTF-NIR Analyser (Brimrose) in the reflectance mode. Each sample was scanned twice in the 1100- 2300 nm spectral range. Partial least squares (PLS) regression was applied to the spectral data through Unscramble software (version 8.0.5)to develop a calibration model capable of estimating the CPcontent of the samples. As a result, correlation coefficients of 0.95, 0.86 and 0.88 were obtained for calibration, cross validation and external validation respectively. Moreover, low standard errors were achieved. The standard error of calibration (SEC) was 0.52, the standard error of cross validation (SECV) was 0.88 and finally, the standard error of prediction was 0.75.