Non-destructive analysis of absorption and reduced scattering coefficients of green and golden kiwifruit

Decoupling optical properties of fruit and vegetables appears challenging, but necessary to get a better insight into the relationship between light and product attributes. In this study, 'SunGold™' and 'Hayward' kiwifruit data were obtained using a laser diode emitting at 785 nm. A camera was employed for capturing the diffuse reflectance of the kiwifruit. Light attenuation profiles were analysed using pre-classification ranges of absorption (µ_a (cm^‑1)) and scattering (µ_s' (cm^‑1)) coefficients and subsequent application of Farrell's diffusion theory to decouple µa and µs'. Results indicate that the optical properties of the fruit were non-destructively analysed in line with values published on kiwifruit earlier. Differences of µ_a and µ_s' were found between cultivars. The coefficient of determination was high considering the prediction of cultivars (R²=0.98) with enhanced classification accuracy when using the absorption and scattering coefficients. The non-destructive approach appears to be suitable for inline sorting.