Application of visible/<scp>NIR</scp> spectroscopy for the estimation of soluble solids, dry matter and flesh firmness in stone fruits
Alessio Scalisi, M.G. O’Connell
Abstract
Abstract BACKGROUND Soluble solids concentration (SSC), dry matter concentration (DMC) and flesh firmness (FF) are important fruit quality parameters in stone fruits. This study investigated the ability of a commercial visible/near‐infrared (NIR) spectrometer to determine SSC, DMC and FF in nectarine, peach, apricot and Japanese plum cultivars at harvest. The work was conducted in summer 2019/2020 on 14 stone fruit cultivars at Tatura, Australia. Two sub‐samples of 100 fruit each were collected before and after commercial maturity (± 5 days) in order to maximize sample variability. RESULTS Partial least square (PLS) regression models based on the second derivative of the absorbance in the 729–975 nm spectral region proved accurate for the prediction of SSC and DMC ( R 2 CV > 0.750). Only the model generated for SSC in ‘Golden May’ apricot was less precise compared to other cultivars. No visible/NIR models were accurate enough to predict FF in the cultivars under study ( R 2 CV < 0.750). CONCLUSION This study demonstrated that the visible/NIR spectrometer was a reliable tool to monitor SSC and DMC in stone fruits at harvest but proved less useful for FF estimation. These results highlight the potential of visible/NIR spectrometry to evaluate stone fruit quality both in situ pre‐harvest and in the laboratory after harvest. © 2020 Society of Chemical Industry