1. CITAB – Centre for the Research and Technology of Agro-Environment and Biological Sciences, Universidade de Trás-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal.
2. CQVR – Centro de Quimica Vila Real, Universidade de Trás-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal.
3. Instituto Nacional de Investigação Agrária e Veterinária, Av. República, Nova Oeiras, 2784-505 Oeiras, Portugal.
4. Department of Food Industries, ESAV, Polytechnic Institute of Viseu, CI&DETS, 3500-606 Viseu, Portugal.
5. Institut für Pflanzenbau und Bodenkunde, Julius Kühn-Institut, Bundesforschungsinstitut für Kulturpflanzen, Bundesallee 50, D-38116 Braunschweig, Germany.
6. Corresponding author. Phone: +351 259 350 751. Fax: +351 259 350 327.