Share Email Print
cover

Proceedings Paper

Time-resolved reflectance spectroscopy for nondestructive assessment of fruit and vegetable quality
Author(s): Alessandro Torricelli; Lorenzo Spinelli; Maristella Vanoli; Anna Rizzolo; Paola Eccher Zerbini
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

In the majority of food and feed, due to the microscopic spatial changes in the refractive index, visible (VIS) and near infrared (NIR) light undergoes multiple scattering events and the overall light distribution is determined more by scattering rather than absorption. Conventional steady state VIS/NIR reflectance spectroscopy can provide information on light attenuation, which depends both on light absorption and light scattering, but cannot discriminate these two effects. On the contrary, time-resolved reflectance spectroscopy (TRS) provides a complete optical characterisation of diffusive media in terms of their absorption coefficient and reduced scattering coefficient. From the assessment of the absorption and reduced scattering coefficients, information can then be derived on the composition and internal structure of the medium. Main advantages of the technique are the absolute non-invasiveness, the potentiality for non-contact measurements, and the capacity to probe internal properties with no influence from the skin. In this work we review the physical and technical issues related to the use of TRS for nondestructive quality assessment of fruit and vegetable. A laboratory system for broadband TRS, based on tunable mode-locked lasers and fast microchannel plate photomultiplier, and a portable setup for TRS measurements, based on pulsed diode lasers and compact metal-channel photomultiplier, will be described. Results on broadband optical characterisation of fruits and applications of TRS to the detection of internal defects in pears and to maturity assessment in nectarines will be presented.

Paper Details

Date Published: 22 October 2007
PDF: 8 pages
Proc. SPIE 6761, Optics for Natural Resources, Agriculture, and Foods II, 67610Y (22 October 2007); doi: 10.1117/12.751793
Show Author Affiliations
Alessandro Torricelli, ULTRAS-INFM-CNR and IFN-CNR, Politecnico di Milano (Italy)
Lorenzo Spinelli, ULTRAS-INFM-CNR and IFN-CNR, Politecnico di Milano (Italy)
Maristella Vanoli, CRA-IVTPA, Istituto Sperimentale per la Valorizzazione Tecnologica dei Prodotti Agricoli (Italy)
Anna Rizzolo, CRA-IVTPA, Istituto Sperimentale per la Valorizzazione Tecnologica dei Prodotti Agricoli (Italy)
Paola Eccher Zerbini, CRA-IVTPA, Istituto Sperimentale per la Valorizzazione Tecnologica dei Prodotti Agricoli (Italy)


Published in SPIE Proceedings Vol. 6761:
Optics for Natural Resources, Agriculture, and Foods II
Yud-Ren Chen; George E. Meyer; Shu-I Tu, Editor(s)

© SPIE. Terms of Use
Back to Top