TY  - JOUR
A1  - Zude-Sasse, Manuela
A1  - Hashim, Norhashila
A1  - Hass, Roland
A1  - Polley, Nabarun
A1  - Regen, Christian
T1  - Validation study for measuring absorption and reduced scattering coefficients by means of laser-induced backscattering imaging
JF  - Postharvest Biology and Technology
N2  - Decoupling of optical properties appears challenging, but vital to get better insight of the relationship between light and fruit attributes. In this study, nine solid phantoms capturing the ranges of absorption (μa) and reduced scattering (μs’) coefficients in fruit were analysed non-destructively using laser-induced backscattering imaging (LLBI) at 1060 nm. Data analysis of LLBI was carried out on the diffuse reflectance, attenuation profile obtained by means of Farrell’s diffusion theory either calculating μa [cm−1] and μs’ [cm−1] in one fitting step or fitting only one optical variable and providing the other one from a destructive analysis. The nondestructive approach was approved when calculating one unknown coefficient non-destructively, while no ability of the method was found to analysis both, μa and μs’, non-destructively. Setting μs’ according to destructive photon density wave (PDW) spectroscopy and fitting μa resulted in root mean square error (rmse) of 18.7% in comparison to fitting μs’ resulting in rmse of 2.6%, pointing to decreased measuring uncertainty, when the highly variable μa was known.

The approach was tested on European pear, utilizing destructive PDW spectroscopy for setting one variable, while LLBI was applied for calculating the remaining coefficient. Results indicated that the optical properties of pear obtained from PDW spectroscopy as well as LLBI changed concurrently in correspondence to water content mainly. A destructive batch-wise analysis of μs’ and online analysis of μa may be considered in future developments for improved fruit sorting results, when considering fruit with high variability of μs’.
KW  - Absorption
KW  - European pear
KW  - Fruit quality
KW  - Phantoms
KW  - Reduced scattering coefficient
KW  - Scattering
KW  - Spatially resolved spectroscopy
Y1  - 2019
U6  - https://doi.org/10.1016/j.postharvbio.2019.04.002
SN  - 0925-5214
SN  - 1873-2356
VL  - 153
SP  - 161
EP  - 168
PB  - Elsevier
CY  - Amsterdam
ER  -