Rapid and non-destructive determination of soluble solids content and titratable acidity in apricot using near-infrared spectroscopy
Résumé
Near-infrared (NIR) spectroscopy technique was used for a rapid and robust accurate determination of apricot fruit quality traits such as titratable acidity (TA) and soluble solids content (SSC). Experiments were carried out during two consecutive years (2005 and 2006). In 2005, four apricot cultivars (‘Badami’, ‘Bergeron’, ‘Goldrich’, and ‘Moniquí’) and four apricot selections (‘A 3759’, ‘A 3844’, ‘A 4034’, and ‘Iranian selection’) from different genetic origins and covering a large phenotypic variability in apricot fruit characteristics were collected at different maturity stages. In 2006, 183 hybrids coming from the cross ‘Goldrich’ x ‘Moniquí’ were analyzed. Both FT-NIR spectra on intact fruits and biochemical measurements (SSC and TA) were performed in representative samples. The FT-NIR spectra were measured using an integrating sphere (diffuse reflectance). Partial least-squares (PLS) regression was applied to develop NIR calibration models which were cross validated to evaluate the prediction ability. Statistical tools as determination coefficient (R2) and Root Mean Square Error of Prediction (RMSEP) were used to evaluate the performance of developed models. NIR models allowed a good prediction of soluble solids content (SSC) and titratable acidity (TA) (for example in 2005, models showed R2 values of 0.84 and 0.79, and RMSEP values of 0.98 and 3.62 for SSC and TA respectively). The NIR measurement technique allowed the determination of biochemical quality attributes (soluble solids content and acidity) in apricot fruit. Compared to traditional method, the NIR method is faster and non-destructive, which could be very useful for the apricot fruit industry