Short communication Prediction of total antioxidant capacity of red wine by Fourier transform infrared spectroscopy Andrea Versari a, * , Giuseppina Paola Parpinello a , Francesca Scazzina b , Daniele Del Rio b a Dipartimento di Scienze degli Alimenti, Università degli Studi di Bologna, Pzza Goidanich 60, Cesena (FC) 47023, Italy b Dipartimento di Sanità Pubblica – sez. Igiene, Facoltà di Medicina e Chirurgia, Università degli Studi di Parma, Via Volturno 39, Parma 43100, Italy article info Article history: Received 26 June 2009 Received in revised form 28 October 2009 Accepted 7 November 2009 Keywords: FTIR FRAP Quality control Polyphenolic compounds abstract Fourier transform infrared (FTIR) spectroscopy provides rapid and nondestructive analysis of wine, with almost no sample preparation. Aim of this study was to use FTIR measurement for the prediction of red wine total antioxidant capacity (TAC). Partial-least squares (PLS) regression was chosen for the evaluation of FTIR spectra. Plot of the full cross-validated PLS predicted TAC values showed a good correlation (r = 0.85), the slope of 0.74 and the prediction error provided by the PLS model was consistent with the uncertainty derived from the reference method. In conclusion, FTIR spectroscopy is a promising tech- nique to rapidly provide information on TAC of red wines and has a high potential to be implemented for the rapid screening of several TAC methods concurrently. Ó 2009 Elsevier Ltd. All rights reserved. 1. Introduction Natural antioxidants of fruits and vegetables, including poly- phenolic compounds, are associated with a reduction in the inci- dence of cardiovascular diseases and cancers and their inclusion in the diet is highly recommended (Pratt, 1992; Rice-Evans & Pack- er, 1998). Red wine contains up to 4000 mg/L of phenolic com- pounds that are believed to be effective in the prevention of these oxidative stress related diseases (Frankel, Waterhouse, & Teissedre, 1995; Renaud & De Lorgeril, 1992; Soleas, Diamandis, & Goldberg, 1997). It is well known that red wines have a complex phenolic com- position and not all phenolics have the same antioxidant activity. However, the levels of single antioxidants in wine do not necessar- ily reflect their total antioxidant capacity (TAC); this also depends on the interactions among the different compounds present in wine. The total antioxidant capacity is the measure of the moles of a given free radical scavenged by a test solution. Although the terms ‘antioxidant capacity’ and ‘antioxidant activity’ are often used interchangeably, their real meanings are quite distinct. The term antioxidant activity should be restricted to characterize the rate constant of single antioxidants against a given oxidant and it is just one of the aspects that contribute to determine TAC (Serafini & Del Rio, 2004). Among the several wet chemistry methods developed to quan- tify TAC, the ferric reducing antioxidant potential (FRAP) assay (Benzie & Strain, 1996) measures the ‘reducing power’ – the ability of a sample to reduce the colorless ferric-tripyridyltriazine com- plex (TPTZ–Fe 3+ ) to its ferrous colored form (TPTZ–Fe 2+ ). It is a sim- ple and highly reproducible spectrophotometric assay using Fe(II) as a standard. Despite several antioxidant methods are correlated each other (Pellegrini et al., 2003) the different methods used often limit the agreement among different studies. Therefore, there is a need of a convenient method for the fast quantitation of antioxidant capac- ity suitable for screening in the food and nutraceutical industry. In this view the development of infrared (IR) spectrometers in combi- nation with chemometric methods, make the IR spectroscopy an interesting tool for research, routine analysis and process control of antioxidant activity (Lam, Proctor, Howard, & Cho, 2005). The FTIR technology provides rapid, reproducible, nondestructive, mul- ticonstituent analysis of food sample, with minimal or no sample preparation. The mid-IR spectrometry is being used for composi- tional analysis or discrimination purposes several food, including wine, and the typical analytes that have been measured are etha- nol, pH, organic acids, sugars and glycerol (Bauer et al., 2008; Urtu- bia, Pérez-Correa, Pizarro, & Agosin, 2008). Few studies are also available on its application for selected polyphenolic compounds such as tannins (Jensen, Egebo, & Meyer, 2008) and anthocyanins (Versari, Boulton, & Parpinello, 2006). The aim of this study is to use fast, inexpensive FTIR measure- ment for the prediction of antioxidant capacity of red wine. This 0956-7135/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodcont.2009.11.001 * Corresponding author. Tel.: +39 0547 338111; fax: +39 0547 382348. E-mail address: andrea.versari@unibo.it (A. Versari). Food Control 21 (2010) 786–789 Contents lists available at ScienceDirect Food Control journal homepage: www.elsevier.com/locate/foodcont