Optical study to identify and quantify capsaicin in optical window

Manuel Abraham López Pacheco; José Javier Báez Rojas; Jorge Castro-Ramos; José Fabian Villa Manríquez; Karen Esmonde-White

doi:10.1016/j.heliyon.2020.e05797

Optical study to identify and quantify capsaicin in optical window

Heliyon. 2021 Mar 17;7(3):e05797. doi: 10.1016/j.heliyon.2020.e05797. eCollection 2021 Mar.

Authors

Manuel Abraham López Pacheco¹, José Javier Báez Rojas¹, Jorge Castro-Ramos¹, José Fabian Villa Manríquez¹, Karen Esmonde-White^{2

3}

Affiliations

¹ Instituto Nacional de Astrofísica Óptica y Electrónica (INAOE), Tonanzintla, Mexico.
² Kaiser Optical System, Inc., Ann Arbor, MI, USA.
³ University of Michigan Medical School, Ann Arbor, MI, USA.

Abstract

Capsaicin is an active compound in hot peppers. It has been studied for its health benefits for humans. Optical spectroscopy is an important tool for determining the optical properties or chemical composition of matter. The aim of this research is proposing an optical method to identify and quantify capsaicin in the visible range. To achieve this goal, we combined absorption and diffuse reflectance spectroscopy techniques to compute the extinction coefficient. Moreover, the concentration of the analytes was determined using the optical properties of capsaicin. Our method is a promising tool for developing a classification of capsaicin according to its percentage in chilies. The extinction coefficients are reported for 507nm and 663nm, which are the most significative. In addition, the coefficients to build the mathematical model for capsaicin are reported for Kubelka-Munk model. Finally, a comparison between capsaicin vs chilies spectra was obtained to identify spectral response. Diffuse reflectance signals allowed the identification of capsaicin and opened the possibility of this fast and easy to do method for classification and quantification of bioactive compounds.

Keywords: Absorption; Capsaicin; Optical window; Spectroscopy.