Dry-matter - a better predictor of the post-storage soluble solids in apples?

The accuracy of dry-matter (DM) and soluble solids content (SSC) predictions, based on 800-1000 nm near infrared spectrometric measurements, are reported for 'Royal Gala' apples (Malus domestica Borkh.). Predictive models were created from spectral and constituent measurements made either immediately after harvest or after 6 weeks cool storage. All DM predictive models were very accurate (R-2 > 0.95, rmsep < 0.32%), whether at harvest or post-storage. The SSC predictive models were more accurate post-storage (R-2 = 0.94, rmsep = 0.32%) than at harvest time (R-2 = 0.79, rmsep = 0.51%). Harvest-time DM predictions were strongly correlated with the post-storage SSC (R-2 = 0.93) and so provide the means of, at least, rank ordering the apples in terms of post-storage SSC. (C) 2002 Elsevier Science B.V. All rights reserved.