Measuring soluble solids distribution in kiwifruit using near-infrared imaging spectroscopy

A near-infrared imaging spectrometer was used to measure the spatial distribution of soluble solids across cut faces of kiwifruit (Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson cv. 'Hayward'). Reflectance spectra from 650 nm to 1100 nm were measured with a spatial resolution greater than 1.2 line-pairs per millimetre across the cut fruit. A near-infrared calibration was obtained by recording the soluble solids concentration of plugs cut from thin slices of fruit and relating these to spectra collected in the same areas from which the plugs were taken. A prediction error of 1.2 degrees Brix over a range of 4.7-14.1 degrees Brix was achieved. These models were used to show the spatial distribution of soluble solids concentrations over cut sections of fruit. (C) 1998 Elsevier Science B.V. All rights reserved.