Bertoldi, D.

Camin, F.

Larcher, R.

Nicolini, G.

Paolini, M.

Santato, D.

Bertoldi, Daniela

Camin, Federica

Paolini, Mauro

Nicolini, Giorgio

Larcher, Roberto

Archivio istituzionale della ricerca - Fondazione Edmund Mach

*@{., o "n,:;:J,?; :,1; ",,"61 FoNDAZToNEw [,P#H*o, rBOOK OrAB$TRACT$3nd MS Food Day2013 0ctober g-11T rentCI ltatyOrganised by:Fnndnzi*ne ffidmr*nd l\lla*hIt*lian Chsmi*ml $**i*tv3'd Ms FooD DAY 2o1gOctober g-11,2013University of TrentoBOOK OFABSTRACTSFranco BiasioliEditorFondazione Edmund Mach - 2013prtrlr i, i' IP.94 - Elemental and isotopic profiling: a tool for distinguishing the botanical origin ofoenological tanninsDaniela Bertoldi*, Alessandro Santato, Federica Camin, Mauro Paolini, Giorgio Nicolini,Roberto LarcherFondazione Edmund Mach ("*l'Jìî,!,;Y;::!,r!3r12:i.,?"" Michere ail'Adige (rN)' ItarvSummary: Oenological tannins are natural products extracted from different botanical sourcessuch as galls, wood and grape tissues. Forty-four samples of commercial tannins from 7different and known botanical sources were analysed to determine the mineral profile andisotopic ratio 13Cllzc, using ICP-MS and IRMS respectively. Canonical discriminant analysisperformed using these combined approaches made it possible to determine the botanical originof commercial tannins, achieving good separation between samples and IÙOVo correctreclassification.Keywords: Oenological tannins; ICPMS; IRMSIntroductionAccording to the International Oenological Codex of the O.I.V., oenological tannins are naturalproducts extracted from different botanical sources. In winemaking these products are usedmainly as clarification/fining agents for wines and musts, but the European authorities alsorecognise the role of tannins as flavourings and food ingredients. These polyphenoliccompounds can have effects on wine structure, colour, flavour and astringency and could act asantioxidant and antimicrobial agents [1]. The characterisation and identification of tannins isuseful in terms of official checks and fulfilment of winemakers' requirements. The ultravioletabsorption spectrum, content of specific phenolic compounds and polyalcohol andmonosaccharide composition were used to characterise and distinguish oenological tanninsaccording to their botanical origin l2-5l.Determination of mineral profile and stable isotoperatios, together with proper statistical processing has already been shown to be very effective indifferentiating the geographical and/or botanical origin of different products, such as tomatoes,cheese, cereal and coffee [6-9]. This work, for the first time to the best of our knowledge,investigates the possibility of determining the botanical origin of commercial tannins on thebasis of mineral profile and analysis of the isotopic ratio l3Cl12C.Experimental methodForty-four samples of commercial oenological tannins of known botanical origin werecollected. In detail, 15 samples were from oak, 15 from grapes (7 from seeds and 8 from skin),3 from gall, 4 from quebracho, 4 from fruit trees and 3 from chestnut. The tannins weremineralized with ultrapure HNO3 in closed vessels using a microwave digester (UltraWAVE,Milestone, Italy; max temperature 240"C). Analysis of Li, Be, B, Na, Mg, Al, P, K, Ca, Ti, V,Cr,  Mn, Fe, Co, Ni ,  Cu, Zn,Ga, Ge, As, Se, Rb, Sr,  Y,  Mo, Pd, Ag, Cd, In,  Sn, Sb, Te, Cs, Ba,La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Er, Tm, Yb, Re, Ir, Pt, Au, Hg, Tl, Pb, Bi, Th and U wascarried out using an ICP-MS (Agilent 7500ce Agilent Technologies, Japan) equipped with anOctopole Reaction System for removal of the principal polyatomic interferences. The l3Cl12Cratio was directly measured using an IRMS (DELTA V, Thermo Scientific, Germany) aftertotal combustion in an elemental analyser (EA Flash lIl2, Thermo Scientific or Vario EL III,Elementar Analysensysteme GmbH). The isotope values were expressed in 6%o against theinternational standard Vienna-Pee Dee Belemnite (V-PDB).281ResultsTannins from oak were characterised by a high Tl content and low content of V, Ga and rareearths; tannins from gall showed a low Li, Na and Cu content, while those from chestnut had ahigh content of Al, Ti, Mn, Co, Ag, Cd, ba, Pb, Th and rare earths. Quebracho tannins werecharacterised by a high Li,Cr, Sr and Hg content. Tannins from grape seeds had a high Gecontent and low content of Mg, Co, Ni, Mn and Cd, whereas samples from grape skin had ahigh Mo, Sn, Sb, Re and U content. Tannin from grape tissues showed a high P, K, As and Cucontent and a low Be content. To assess efficiency in terms of discriminating the botanicalorigin of tannins, principal component analysis was performed using all the parametersanalysed. Only elements with factor loadings of > 0.5 in at least one of the first three principalcomponents were used to perform canonical discriminant analysis (I3C|IZC, Li, Be, B, Ntr,Mg, A1, Ca, Ti ,  V,  Mn, Fe, Co, As, Se, Rb, Sr,  Y,  Mo, Pd, As, Cd,In,  Sn, Sb, Cs, Ba, Tl ,  Pb, Thand U, standardised data). The combination of the first 2 canonical variables accounted for 837oof variability, assuring good discrimination of the samples in the 7 botanical groups, and all thesamples were correctly re-classified (Figure. 1).o oaKr gall' grape seeds^ grape skin+ chestnut' quebracho* f ruit tree- 1 5  --20o -10 o ,oo' uar.'o 20 soFigure.I Scatter plot of the first two canonical variables in canonical discriminant analysis of theelemental and isotopic composition of tannins from 7 botanical sourcesConclusionUsing the "classic" approach based on analysis of sugars suggested by the O.I.V. the ability todifferentiate the botanical origin of tannin in 827o of samples has already been proved [4]. Morerecently, an approach which coupled sugar and phenol content made it possible to correctlyreclassify 937o of tannins [5]. The results achieved with joint use of the mineral profile and 13Cisotopic ratio proved the effectiveness of these approaches in terms of providing practicalsupport for assessing the real origin of these expensive food coadiuvants.References[1] A.Versari, W. du Toit, G.P. Parpinello; Australian Journal of Grape Wine Research, 19 (2013), pp.l-1 0 .[2] M.H. Salagoity-Auguste, C. Tricard, F. Marsal, P. Sudraud; Am J Enol Vitic,3l(4) 1986, pp. 301-303.t3l N.Vivas, N. Marie-Frangoise, N. Vivas de Gaulejac, C. Absalon, A. Bertrand, M. Mirabel; Anal ChimAcra, 513 (2004), pp. 247 -256.[4] M.L. Sanz, L Martínez-Castro, M.V. Moreno-Arribas; Food Chem, 111 (2008) ,pp.778-783.[5] M.Malacarne, T. Nardin, D. Bertoldi, G. Nicolini, R. Larcher; In Vino Analytica Scientia Symposium(2013),Reims 2 -5 JuIy.t6l L.Bontempo, F. Camin, L. Manzocco, G. Nicolini, R. Wehrens,L.Zlller, R. Larcher; Rapid CommumMass Sp,25 (2011), pp.899-909.t7l D.Goitom Asfaha, C.R. Quetel, F. Thomas, M. Horacek, et al.;J Cereal Sci,53 (201I),pp.170-177.t8l A. Santato, D. Bertoldi, M. Perini, F. Camin, R. Larcher; J Mass Spectrom, 47 (2012),pp.ll32-lL40.t9l F.Camin, R. Wehrens, D. Bertoldi, L. Bontempo, L.Zlller,M. Perini, G. Nicolini, M. Nocetti., R.Larcher; Anal Chim Acta, I Il (2012), pp. 54- 59 .5N 0oE288r sBN 978- 88- 7843- 035- IruIffilffiffiffiil!rtúfs*rf*fI(}+rHC}L,F.80X.3 (}ctoh*r !l*[f

Elemental and isotopic profiling: a tool for distinguishing the botanical origin of oenological tannins

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Elemental and isotopic profiling: a tool for distinguishing the botanical origin of oenological tannins

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