Acknowledgments
The authors are thankful to Fundação para a Ciência e a Tecnologia
for financial support in the framework of the project POCI/
AGR/61543/2004 and for the Ph.D. grants of Rita Alves (SFRH/BD/
22449/2005) and Cristina Soares (SFRH/BD/39360/2007). We also
thank BICAFÉ for providing coffee samples.