Determination of capsaicin, ascorbic acid, total phenolic compounds and antioxidant activity of Capsicum annuum L. var. serrano by mid infrared spectroscopy (Mid-FTIR) and chemometric analysis

Fourier transform mid-infrared (Mid-FTIR) spectroscopy in conjunction with multivariate analysis was used to predict the capsaicin content, ascorbic acid, total phenolic compounds, and antioxidant activity of Capsicum annuum L. variety serrano. Two multivariate calibrations, partial least square (PLS), and principal component regression (PCR) were optimized to construct the calibration models. The best models used to quantify the above mentioned compounds were obtained with the PLS algorithm and coefficients of determination (R²) greater than 0.998 as well as a standard error calibration less than 0.098. The results demonstrated that Mid-FTIR spectroscopy in combination with multivariate analysis can be effectively used for to quantify the capsaicin, ascorbic acid, total phenol content, and antioxidant activity of Capsicum annuum var. serrano. Mid-FTIR spectroscopy in combination with multivariate calibration offers rapid, easy sample preparation, is environmentally friendly, and is operationally uncomplicated, demonstrating the significant advantages of the chemometric models compared with conventional methods of analysis.