Feasibility of NIR spectroscopy for non-destructive characterization of table olive traits

Abstract

Near infrared spectroscopy (NIRS) was used to assess the properties of intact olives. Spectral data over a range of wavelengths from 400 to 2498nm were recorded for 448 fruit samples collected in 2008 and 2009 from seedlings of different crosses in a table olive breeding program. Although it was confirmed that the predictive models were not transferable from 1year to the next, accurate calibration models were obtained for chemical parameters, such as oil and moisture contents (RPD values between 4.83–4.91 and 2.70–3.01, respectively). By combining the 2008 and 2009 data sets, good calibration models were obtained for some interesting physical parameters, such as fruit weight, fruit equatorial diameter and fruit volume, with RPD values of 3.34, 3.36 and 3.25, respectively. Poorer accuracy was observed for the fruit longitudinal diameter, pulp-stone ratio, endocarp equatorial diameter and stone weight, with RPD values of 2.12, 2.09, 1.84 and 1.78, respectively. The results show that NIRS is a useful, rapid and non-destructive technique for the table olive dressing industry and genotype selection programs.