Abstract

Time-resolved reflectance has been used for the nondestructive measurement of optical properties in apples. The technique is based on the detection of the temporal dispersion of a short laser pulse injected into the probed medium. The time distribution of re-emitted photons interpreted with a solution of the diffusion equation yields the mean values of the absorption and reduced scattering coefficients of the medium. The proposed technique proved useful for the measurement of the absorption and scattering spectra of different varieties of apples, revealing the spectral shape of chlorophyll. No major variations were observed in the experimental data when the fruit was peeled, showing that the optical properties measured were those of the pulp. With this technique the change in chlorophyll absorption during storage and ripening could be followed. Finally, a compact prototype working at few selected wavelengths was designed and constructed, demonstrating potentialities of the technique for industrial applications.

Nondestructive quantification of chemical and physical properties of fruits by time-resolved reflectance spectroscopy in the wavelength range 650–1000 nm

Rinaldo Cubeddu, Cosimo D’Andrea, Antonio Pifferi, Paola Taroni, Alessandro Torricelli, Gianluca Valentini, Colin Dover, David Johnson, Margarita Ruiz-Altisent, and Constantino Valero
Appl. Opt. 40(4) 538-543 (2001)

Monitoring of fruit freshness using phase information in polarization reflectance spectroscopy

M. Sarkar, N. Gupta, and M. Assaad
Appl. Opt. 58(23) 6396-6405 (2019)

Optical properties of apple skin and flesh in the wavelength range from 350 to 2200 nm

Wouter Saeys, Maria A. Velazco-Roa, Suresh N. Thennadil, Herman Ramon, and Bart M. Nicolaï
Appl. Opt. 47(7) 908-919 (2008)

Accuracy and precision of tissue optical properties and hemodynamic parameters estimated by the BabyLux device: a hybrid time-resolved near-infrared and diffuse correlation spectroscopy neuro-monitor

Martina Giovannella, Lorenzo Spinelli, Marco Pagliazzi, Davide Contini, Gorm Greisen, Udo M. Weigel, Alessandro Torricelli, and Turgut Durduran
Biomed. Opt. Express 10(5) 2556-2579 (2019)

In vivo time-resolved reflectance spectroscopy of the human forehead

Daniela Comelli, Andrea Bassi, Antonio Pifferi, Paola Taroni, Alessandro Torricelli, Rinaldo Cubeddu, Fabrizio Martelli, and Giovanni Zaccanti
Appl. Opt. 46(10) 1717-1725 (2007)