Rapid quantification of total phenolics and ferulic acid in whole wheat using UV-Vis spectrophotometry

Wheat phenolic compounds have benefits of maintaining health and reducing risks of some chronic diseases and cancers. Wheat breeders and producers are becoming interested in producing specialty wheat with a higher amount of bioactive phenolics, in addition to the conventional targets of yield, disease and pest resistance, milling and baking quality, etc. Generally, total phenolic content (TPC) is determined using Folin-Ciocalteu reagent, and phenolic acids are quantified through the chromatography methods, which are relatively time-consuming and labor-intensive. In this study, we developed partial least squares (PLS) models for rapid, simplified, and accurate determination of both TPC and ferulic acid of whole wheat extract based on spectra data from UV-Vis spectroscopy. The spectra ranged from 240 to 360 nm were used for model development. A total of 60 samples was used as a calibration set, and 20 samples were used as an external validation set. For the TPC model, the values of both R-2-calibration and R-2-cross validation were 0.89. For the ferulic acid model, R-2-calibration was 0.82, and R-2-cross validation was 0.78. Compared with the traditional analytical methods, our approach is more convenient and rapid and achieves comparable accuracy. Wheat breeding programs, as well as other projects focusing on the health benefits of whole wheat that require fast screening and selection of wheat lines with significant phenolic compounds, will be greatly benefitted by this new method.