Geographical provenancing of purple grape juices from different farming systems by proton transfer reaction mass spectrometry using supervised statistical techniques
*Granato, D., Koot, A. and van Ruth, S. M. (2015). Journal of the Science of Food and Agriculture, 95(13), 2668–2677.
BACKGROUND: Organic, biodynamic and conventional purple grape juices (PGJ; n = 79) produced in Brazil and Europe werecharacterized by volatile organic compounds (m/z 20–160) measured by proton transfer reaction mass spec trometry (PTR-MS),and classiﬁcation models were built using supervised statistical techniques.
RESULTS: k-Nearest neighbours and soft independent modelling of class analogy (SIMCA) models discriminated adequatelythe Brazilian from European PGJ (overall eﬃciency of 81% and 87%, respectively). Partial least squares discriminant analy-sis (PLSDA) classiﬁed 100% European and 96% Brazilian PGJ. Similarly, when samples were grouped as either conventional ororganic/biodynamic, the PLSDA model classiﬁed 81% conventional and 83% organic/biodynamic juices. Intraregional PLSDAmodels (juices produced in the same region – either Europe or Brazil) were developed and were deemed accurate in discrimi-nating Brazilian organic from conventional PGJ (81% eﬃciency), as well as European conventional from organic/biodynamic PGJ(94% eﬃchancy).
CONCLUSIONS: PGJ from Brazil and Europe, as well as conventional and organic/biodynamic PGJ, were distinguished withhigh eﬃcienc y, but no statistical model was able to diﬀerentiate organic and biodynamic grape juices. These data support thehypothesis that no clear distinction between organic and biodynamic grape juices can be made with respect to volatile organiccompounds.
Research publications concerning biodynamics