The authors are grateful to the São Paulo Research Foundation (FAPESP) for funding project nos. 2010/05241-8 and 2010/05240-1, and for the fellowship awarded to MTK Kubo (2011/09220-8). The authors are also grateful to Prof. Dr. Carlos R. F. Grosso, Tech. Yara Fagnani Honório, Profa. Dra. Adriana Z. Mercadante and Dr. Renato Grimaldi (University of Campinas) for the support given with the PSD, color, optical and electronic microscopy analyses.