Images obtained by Magnetic Resonance Imaging (MRI) of apricots during ripening were analysed by texture analysis (TA) to determine the correlation between TA parameters and firmness, soluble solids content (SSC), titratable acids and production of ethylene. Fruits in selected harvesting terms differ significantly in SSC, acidity and the firmness of the fruits. Three sagital T2w slices measured at 4.7T (resolution 256 x 256 pixels) were analyzed numerically using the software MaZda 2.10 and the statistical package S-PLUS 4.5.  A significant correlation was found between selected physical and chemical characters and TA parameters such as sum average, sum variance and sum entropy. The dynamics of the TA parameters during the periods of maturation can be described by polynomial trends.

The following distinctive TA parameters were found: skewness and kurtosis (among histogram-based parameters), variance of absolute gradient (among gradient-based parameters), grey level nonuniformity (among run length matrix-based parameters) and especially some co-occurrence matrix-derived parameters such as correlation, sum average, sum variance and sum entropy (within 1-, 3-, and 5-pixel neighbourhoods).

Keywords:

magnetic resonance; texture analysis; T2w maps; proton density; apricots; NMR; MRI

J. Letal , D. Jirak , J. Golias , L. Suderlova , M. Hajek