Comparative analysis of phenolic acid profiles of rice grown under different regions using multivariate analysis.

This study was conducted to determine the content of phenolic acids in various rice cultivars and to evaluate the impact of genotype versus environmental influence on the phenolic acid profiles of rice grains. Three forms of phenolic acids (free, esterified, and insoluble-bound forms) were identified using gas chromatography–time-of-flight mass spectrometry (GC-TOFMS) in samples of eight Korean rice cultivars (Oryza sativa L.) grown together at two different locations. The phenolic acid profiles were subjected to data mining processes, including principal components analysis (PCA), partial least-squares discriminant analysis (PLS-DA), and orthogonal PLS-DA (OPLS-DA). The results of OPLS-DA showed clear discrimination between the rice samples based on their growing locations rather than by their genotypes. The major components that contributed to the separation between the two regions were sinapic and ferulic acids in both free and bound forms. These results suggest that the phenolic acid composition in rice grains is determined by environmental factors such as growing condition rather than by genetic factors. This study illustrates the utility of metabolite profiling, combined with chemometrics, as a tool for identifying metabolic differences between crop samples from different regions of cultivation.