RT Journal Article SR Electronic T1 Determination of Grape Quality at Harvest Using Fourier-Transform Mid-Infrared Spectroscopy and Multivariate Analysis JF American Journal of Enology and Viticulture JO Am J Enol Vitic. FD American Society for Enology and Viticulture SP 317 OP 322 DO 10.5344/ajev.2008.59.3.317 VO 59 IS 3 A1 Andrea Versari A1 Giuseppina P. Parpinello A1 Alessia U. Mattioli A1 Sergio Galassi YR 2008 UL http://www.ajevonline.org/content/59/3/317.abstract AB A rapid method for the simultaneous measurement of gluconic acid and glycerol, two important chemical markers of grape infection, was developed using Fourier-transform mid-infrared (FT-MIR) spectroscopy. The method used a combination of FT-MIR with partial-least squares (PLS) regression and compositional data of Trebbiano and Sangiovese grapes obtained with high performance ion-exchange chromatography (HPLC). A total of 320 grape samples were analyzed, including grapes hand picked in the vineyards (200 samples) and mechanically sampled from trucks upon arrival at the wineries (120 samples). Gluconic acid and glycerol increased with increasing percentage of grape infection assessed by visual inspection (r = 0.928). The best result was obtained for gluconic acid (R2 = 0.979; RMSECV = 0.63; RPD = 7.0), indicating that FT-MIR was suitable for process control.