Wavelength selection in vis/NIR spectra for detection of bruises on apples by ROC analysis

► It is feasible to select wavelengths for bruise detection of apples by ROC analysis. ► First derivative spectra in 730-830 nm are effective for bruise detection. ► Four pairs of wavelengths are determined for Fuji, Jonagold, Orin and Sinano Gold. ► Predictive ability of selected wavelengths is on the same level with full spectrum.