Relationship between optical properties and internal quality of potatoes during storage

The optical properties [absorption coefficient (mu(a)) and reduced scattering coefficient (mu(s)')] and internal quality [firmness (FI), moisture content (MC), and soluble solids content (SSC)] of stored potatoes at 25 degrees C were determined, along with ultrastructure observation. Potato tissue ultrastructure changed significantly with storage time, exhibiting enhanced scattering properties and a monotonic increase in mu(s)'. The mu(a) spectra showed significant correlations with MC and SSC, while the mu(s)' spectra were more strongly correlated with FI. The competitive adaptive reweighted sampling (CARS) algorithm improved the prediction accuracy for partial least squares regression (PLSR) and support vector regression (SVR) models. The best predictions were 1st-Derivative-mu(s)'-FI-PLSR (R-P = 0.897, RMSEP = 0.036 N, RPD = 2.262), SG-mu(a) -MC-SVR (R-P = 0.886, RMSEP = 0.438 %, RPD = 2.157), and Raw-mu(a) -SSC-SVR (R-P = 0.873, RMSEP = 0.137 %, RPD = 2.050). These results demonstrate the potential for predicting internal quality using potato's optical properties.