Determination of the Oxidative Stability of Camellia Oils Using a Chemometrics Tool Based on 1H NMR Spectra and α-Tocopherol Content

This study, for the first time, predicts oxidative stability in camellia oils by partial least squares (PLS) built with proton nuclear magnetic resonance (H-1 NMR) and alpha-tocopherol content. The prediction models were established by the PLS method. Outlier detection, latent variables optimization, data pretreatment, and important variables selection were applied for models optimization. All the developed models exhibited good performance as indicated by R-2 > 0.895 and root mean square error of estimation and root mean square error of prediction less than 0.322 and 0.307. For verification of the contribution of H-1 NMR spectra and alpha-tocopherol for prediction performance, a PLS model with fatty acids composition instead of H-1 NMR spectra and one with only H-1 NMR spectra as input variables were developed, respectively. The results showed that the model based on NMR data was more accurate and precise than that based on fatty acid composition data. And the performance of the models was significantly degraded without alpha-tocopherol as input variables.