A Multipurpose Portable Instrument for Determining Ripeness in Wine Grapes Using NIR Spectroscopy

First steps towards the development of a non-destructive technique for the quality control of wine grapes during on-vine ripening and on arrival at the winery

“…The predictive capacity of this equation was higher to that of the equation obtained with grape must (RPD = 2.64) and lower than that recorded using berries (RPD = 3.34). Results for berries were similar to findings reported by Larraín et al (2008): r 2 = 0.91, RMSEP = 1.24°Brix and RPD = 3.40.…”

“…Previous research has demonstrated the potential of NIRS technology for the quantitative characterization of wine grape quality parameters such as soluble solid content (Jarén et al, 2001;Dambergs et al, 2003Dambergs et al, , 2006Herrera et al, 2003;Arana et al, 2005;Cozzolino et al, 2005;Larraín et al, 2008), reducing-sugar content (Fernández-Novales et al, 2009), pH-value (Dambergs et al, 2003Cozzolino et al, 2004Cozzolino et al, , 2005Larraín et al, 2008) and acidity (Chauchard et al, 2004). However, all these studies have used either grape berries or must, thus requiring a certain amount of processing prior to analysis; they have thus failed to exploit one of the major advantages of NIRS, i.e.…”

Brix, pH and anthocyanin content determination in whole Port wine grape berries by hyperspectral imaging and neural networks

“…for sugar content the present results were equivalent to those ofLarrain et al (2008) (Geraudie et al (2009) andHerrera et al (2003). For pH, the present work showed R 2 values similar to the values from Larrain et al; however, the RMSE values were slightly worse than those of Larrain et al Concerning anthocyanin concentration, the R 2 value in the present results was, better and, significantly better than the R 2 of Geraudie et al and the best R 2 of Larrain et al, respectively.…”

“…Transmittance mode spectroscopy (Larrain et al, 2008) competes directly with reflectance mode spectroscopy making it Table 1 Works measuring enological parameters for a small number of whole grape berries using spectroscopic techniques in reflectance mode combined with machine learning methods. Transmittance mode has the disadvantage of requiring close proximity to the measured sample because the intensity of the light coming from the samples is significantly smaller than in the case of reflectance.…”

“…, for sugar content,Larrain et al (2008) reported, for single berries and depending on the grape variety, R 2 values between 0.87 and 0.93. The RMSE varied between 1.1 and 1.2°Brix Herrera et al (2003),and Geraudie et al, (2009).…”