Metais contaminantes nos vinhos. Ocorrência por influência das bentonites

• Author(s): Catarino, Sofia Cristina Gomes
• Date: 2006
• Persistent ID: http://hdl.handle.net/10400.5/534
• Origin: Repositório da UTL
• Subject(s): wine; vinho; must; mosto; contaminant metals; metais contaminantes
• Document Type: Doctoral Thesis
• Language: Portuguese
• Advisor(s): Curvelo-Garcia, António; Sousa, Raul Bruno

Description

Doutoramento em Engenharia Agro-industrial - Instituto Superior de Agronomia A new methodology based on focused ultrasound for must pre-treatment and analytical methods for the determination of contaminant metals of wines, by ETAAS and ICP-MS techniques, have been developded and validated.The composition of wines and their corresponding must in contaminant metals were evaluated. The variation from must to wine depend on the element and its concentration. For a large group of contaminant metals decreases were verified, suggesting an important capacity of elimination.The study of the release of contaminant elements from bentonites to wine showed enrichment for the generality of the elements, strngly related to bentonites characteristics, and highest at lowest pH. Physical, chemical and mineralogical characteristics of bentonites, for the first time connected to its mineral release, revealed several non-conformances with OIV specifications, demonstrating the need for an effective control. The results suggested that nontmorillonite content is not a satisfactory indicator for bentonite reactivity. For bentonite quality control purposes extraction solutions were essayed. The protein nature is an important factor on extraction. The extraction solution with wine protein was a better simulator than the test solution indicated by OIV.