Estimation of dry matter and starch concentration in potatoes by determination of under-water weight and near infrared spectroscopy

Summary Potato food and non-food industries need information about dry matter (DM) and starch concentration of tubers. Therefore, calculation of dry matter concentration and starch concentration via under-water weight were optimised. Determination coefficients (R²) were 0.92 and 0.83 (starch concentration between 13 and 23%), and 0.94 and 0.88 (starch concentration ≥13%) for dry matter and starch concentration, respectively. In a second attempt, near infrared spectroscopy models for both constituents were calculated (R² of validation set was 0.98 and 0.96 for dry matter and starch concentration, respectively). Results pointed out superiority of the near infrared technique with less divergence than the techniques of under-water weighting.