A Case Study of Selected Volatile Phenols from Brettanomyces and Micronutrients Mn, Fe, Cu, Zn in Chianti Red Wines

Volatile phenols 4-Ethylphenol (EtP) and 4-Ethylguaiacol (EtG), and selected metals Mn, Fe, Cu, and Zn in Chianti red wines were determined via Head-Space Solid Phase Micro-Extraction pretreatment and Gas Chromatography-Mass Spectrometry and through Atomic Absorption Spectrophotometry. The wine samples were Chianti Classico DOCG (CdB) and Toscana IGT (CF) from seven vintages 2008-2003, 2001. The concentration for EtP was in the range 283-862 (CdB) and 155-643 μg L-1 (CF), whereas the content of EtG ranged 40-116 (CdB) and 11-104 μg L-1 (CF). The content for metals ranged 1.42-1.82, 0.93-4.68, <0.10-0.20, and 0.53-1.10 mg L-1 for Mn, Fe, Cu, and Zn, respectively. The concentrations for EtP and EtG have high relative values for wines from 2004 and 2007 harvests. Interestingly, Manganese concentration follows a similar trend. Data about the metals and phenols are in agreement with much care at vine/grape and fermentation-aging-refinement procedures.