Prediction of Starch, Moisture, and Sugar in Sweetpotato by Near Infrared Transmittance

Abstract

Near infrared analysis was used to predict the starch, moisture, and sugar content in sliced fresh sweetpotato [Ipomoea batatas (L.) Lam.] storage roots. Samples were collected in each of three growing years. The best calibration equation for starch from combined samples (1989 to 1991) showed a multiple correlation coefficient (R) of 0.949, a standard error of calibration (sec) of 2.01, and a standard error of prediction (sep) of 1.91. The R, sec, and sep for moisture and sugar were 0.930, 1.85, and 2.00, and 0.837, 1.30, and 1.21, respectively. Calibrations based on samples from a given year adequately predicted the variables but could not account for variances introduced by samples from other years. Multiyear calibrations based on several years of data adequately predicted starch and moisture content in root slices. Thus, multiyear calibrations with annual bias adjustments can be applied to screening sweetpotato breeding germplasm for these two variables.