Comparison of reflectance, interactance and transmission modes of visible-near infrared spectroscopy for measuring internal properties of kiwifruit (Actinidia chinensis)

Three modes of visible-near infrared spectroscopic measurement (reflectance, interactance and transmission) were compared for their ability to non-destructively estimate harvest soluble solids content (SSC), density and internal flesh colour of the yellow-fleshed kiwifruit Actinidia chinensis. Interactance mode spectra provided the most accurate estimates of SSC, density and flesh colour. SSC was predicted with a standard error of prediction (SEP) of +/- 0.80 degrees Brix and with correlation coefficient R-2 of 0.93. Whole-fruit densities were predicted with an SEP of +/- 3.6 kg m(-3) and with an R-2 of 0.74. Internal flesh hue angle was predicted with an SEP of +/- 1.6 degrees and with an R-2 of 0.82. (C) 2000 Elsevier Science B.V. All rights reserved.