Identity Confirmation of a Branded, Fermented Cereal Product by UV Spectroscopy: A Feasibility Study Involving a Trappist Beer

Brand protection is important for a food processor; trust in brand identity is essential for consumer confidence. In this study, the combination of UV spectroscopy and multivariate mathematics was investigated to confirm the identity of a processed cereal product a Trappist beer. Samples (52) of Rochefort 8, other Rochefort and non-Rochefort beers, diluted 1:100 with distilled water, were analysed by UV spectroscopy (220-400 nm). Partial least squares discriminant analysis (PLS-DA) and soft independent modelling of class analogy (SIMCA) multivariate methods were applied separately to confirm the identity of Rochefort 8 beer. Spectral data were analysed in both raw and standard normal variate (SNV) pre-treated forms. Using PLS-DA, a two-stage modelling procedure was applied involving initial classification as either Rochefort or non-Rochefort followed by classification within the Rochefort class as Rochefort 8 or non-Rochefort 8. Correct classification rates for these two steps were (a) 100 and 94.4% and (b) 90.9 and 100% respectively. Applying the 3 principal component SIMCA model to the 8 test Rochefort and all of the non-Rochefort (n = 36) samples, 6 of the 8 Rochefort beers were correctly classified (75%; p = 0.05) but only two of the 36 non-Rochefort beers were wrongly classified as Rochefort (correct classification rate of 94.4%).