The primary objective is to assess the efficacy of acute challenge of MP roasted powder compared to Levodopa formulations with a dopa-decarboxylase inhibitor (LD-DDCI) and without (LD+DDCI), and placebo. Levodopa dose with DDCI is administered at 3.5 mg/kg, while Levodopa without DDCI is administered at the equivalent dose. This conversion factor is 5-fold, based on published studies comparing clinical and pharmacokinetic Levodopa effects with and without a DDCI and a previous double blind study on MP in patients with PD. For example, 100mg of Levodopa plus DDCI (either Benserazide or Carbidopa) corresponds to 500mg of Levodopa without any DDCI, obtained by administration of 8.75 grams of MP roasted powder (considering 5.7% of Levodopa in the bolivian ecotype of MP). Levodopa dose from MP is planned to be administered at not only at the equivalent dose of LD+DDCI (i.e. 5-fold), but also at the lower dosage of 3.5-fold.