Determining the Optical Properties of Two-Layer Turbid Materials Based on Spatially Resolved Diffuse Reflectance

Abstract

Hyperspectral imaging-based spatially resolved technique is useful for determining the optical properties of fruits and food products that are homogeneous. To better characterize fruit properties and quality attributes, it is necessary to consider fruit to be composed of two homogeneous layers, i.e., skin and flesh. This research was aimed at developing a nondestructive method to determine the absorption and scattering properties of two-layer turbid materials with characteristics of fruit. An inverse algorithm was developed for extraction of optical properties from the spatially resolved diffuse reflectance data acquired using a hyperspectral imaging system. The diffusion model and inverse algorithm were validated with Monte Carlo simulations and experimental measurements from model samples. The average errors of determining two and four optical parameters were 6.8% and 15.3%, respectively, for Monte Carlo reflectance data. Moreover, the optical properties of the first layer of model samples were determined with errors of less than 23.0% for absorption coefficient and 18.4% for reduced scattering coefficient. The two-layer diffusion model coupled with the hyperspectral imaging-based spatially resolved technique has the potential to measure the optical properties of such turbid materials as fruits and food products.