The sampling procedure consisted of drying mate bark in
a forced air oven (50 ◦C/24 h) and grinding it in a knife mill
(Marconi, MA-580, Piracicaba, Brazil) after the bark was manually
separated from the branches. The dried samples were
frozen at
−40
±
2 ◦C and packaged in airtight plastic bags and
aluminum packages and stored in a freezer (−18
±
2 ◦C) until
required.