Estimation of Theophylline in Black Tea Using NIR Spectroscopy

The present work delivers a study on evaluation of biomarkers present in tea using NIR spectroscopy. Three primary biomarkers theophylline, theobromine, L-theanine found in black tea have immense benefits toward human health. The NIR spectral data for each pure compound of different molarity were examined. The NIR spectrometer experiment was performed in transmission mode within the range of wavelength 900-1700 nm. Chemometrics was imposed for detailed spectral data analysis. Three different compounds were analyzed and distinguished using principal component analysis (PCA). Effective clustering of three compounds was noticed from the PCA plot. A high measure of class separability index for NIR data obtained has been found to be 41.6. The biomarker theophylline was subjected to quantitative prediction and correlation using partial least square regression (PLSR) analysis. Prediction algorithm provided correlation factor of 0.81 with a high value of average prediction accuracy 92.62%. Based on the primary investigation it can be stated that the NIR spectroscopy technique may be implemented for the assessment of different biomarkers present in black tea.