Nondestructive Detection of Soluble Solids Content of Plums Based on UV/Vis Spectroscopy Technology

The spectroscopy technology combined with chemometrics was used to measure soluble solids content of plums and provide a scientific method for nondestructive measurement of plums quality. The spectra acquisition system was used to collect the average spectral reflectance of ‘Red’ and ‘Green’ plums. And the standard normal variation(SNV)was used to preprocess original spectral reflectance. Then the successive projection algorithm(SPA)and competitive adaptive reweighted sampling(CARS)method were used to select characteristic wavelengths. And an error back propagation(BP)network model was established based on full spectra and selected characteristic wavelengths for predicting soluble solids content of plums. The results showed that 31 and 104 characteristic wavelengths were selected from 1024 wavelengths by SPA and CARS,respectively. CARS-BP model had the best calibration ability of soluble solids content of plums(r_c=0.998,RMSEC=0.026)and the best prediction ability of soluble solids content of plums(r_p=0.887,RMSEP=1.767). This study indicates that spectroscopy technology combined with chemometrics is effective for detection on soluble solids content of plums.