Determination of effective wavelengths for discrimination of fruit.pdf

a n a l y t i c a c h i m i c a a c t a 6 1 5 ( 2 0 0 8 ) 10–17 a v a i la b le at ww w.scie ncedirect. com j o u rn al h omepage: www.elsevi er.c om /locate/aca Determination of effective wavelengths for discrimination of fruit vinegars using near infrared spectroscopy and multivariate analysis ∗ Fei Liu, Yong He , Li Wang College of Biosystems Engineering and Food Science, Zhejiang University, 268 Kaixuan Road, Hangzhou 310029, China a r t i c l e i n f o a b s t r a c t Article history: Near infrared (NIR) spectroscopy based on effective wavelengths (EWs) and chemometrics Received 14 January 2008 was proposed to discriminate the varieties of fruit vinegars including aloe, apple, lemon and Received in revised form peach vinegars. One hundred eighty samples (45 for each variety) were selected randomly 11 March 2008 for the calibration set, and 60 samples (15 for each variety) for the validation set, whereas Accepted 12 March 2008 24 samples (6 for each variety) for the independent set. Partial least squares discriminant Published on line 21 March 2008 analysis (PLS-DA) and least squares-support vector machine (LS-SVM) were implemented for calibration models. Different input data matrices of LS-SVM were determined by latent vari- Keywords: ables (LVs) selected by explained variance, and EWs selected by x-loading weights, regression Near infrared spectroscopy coefficients, modeling power and independent component analysis (ICA). Then the LS-SVM Fruit vinegars