Infrared spectroscopy, anthocyanins

To detect adulteration of wine. Bums et al. (2002) found that the ratios of acetylated to p-coumaroylated conjugates of nine characteristic anthocyanins served as useful parameters to determine grape cultivars for a type of wine. Our laboratory utilized mid-infrared spectroscopy combined with multivariate analysis to provide spectral signature profiles that allowed the chemically based classification of antho-cyanin-containing fruits juices and produced distinctive and reproducible chemical fingerprints, making it possible to discriminate different juices. " This new application of ATR-FTIR to detect adulteration in anthocyanin-containing juices and foods may be an effective and efficient method for manufacturers to assure product quality and authenticity. 

Many methods are currently available for the qualitative analysis of anthocyanins including hydrolysis procedures," evaluation of spectral characteristics, mass spectroscopy (MS), " nuclear magnetic resonance (NMR), and Fourier transform infrared (FTIR) spectroscopy. - Frequently a multi-step procedure will be used for... 

Another practice, that does not produce negative effects on health but is considered as a food adulteration, is represented by the blending of wines with a wine very rich in anthocyanins ( Rossissimo ) or by adding anthocyanins extracted by black rice, in order to naturally increase the colour of red wines. However, the study by Ferrari et al. [66] deserves to be mentioned here because it not only compared two different techniques (Fourier transform near-infrared and H NMR spectroscopies), but also applied a series of multivariate classification methods. In particular, PLS-DA was used as... 

Ferrari E, Foca G, Vignah M, Tassi L, Ulrici A. Adulteration of the anthocyanin content of red wines perspectives for authentication by Fourier transform-near infrared and H-1 NMR spectroscopies. Anal Chim Acta 2011 701 139-51. 

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