ARS | Publication request: ASSESSING THE MATURITY OF APPLES BY INTEGRATING HYPERSPECTRAL REFLECTANCE AND FLUORESCENCE IMAGING TECHNIQUES

Submitted to: Michigan State University Controlled Atmosphere Clinic
Publication Type: Experiment Station
Publication Acceptance Date: July 20, 2006
Publication Date: July 21, 2006
Citation: Lu, R., Noh, H. 2006. Assessing the maturity of apples by integrating hyperspectral reflectance and fluorescence imaging techniques. Michigan State University Controlled Atmosphere Clinic. Volume 5(2):209-217.

Technical Abstract: Fluorescence and reflectance are two different forms of light interaction with the matter, and they can be complementary in measuring fruit maturity and quality. In this research, a hyperspectral imaging system was used to acquire both reflectance and fluorescence images from 'Golden Delicious' apples harvested over a 4-week period. Standard destructive tests were performed on measuring multiple maturity parameters including skin and flesh color, fruit firmness, soluble solids, starch, and acid. The reflectance and fluorescence data were analyzed separately and then integrated for predicting apple maturity parameters. The fluorescence prediction models had consistently lower correlations with individual maturity parameters than did reflectance. The integration of reflectance and fluorescence improved maturity measurements over either reflectance or fluorescence; the improvements in the correlation coefficient were noticeable for most parameters (up to 12% for titratable acid). Since fluorescence and reflectance measurements can be performed with the same imaging system rapidly, the integrated technique is useful for better assessment of apple fruit maturity and quality.