Anais do Simpósio Latino Americano de Ciências de Alimentos
Actas del 14 SLACA - Simposio Latinoamericano de Ciencia de los Alimentos

Unconventional food plants (UPC) are used in food and folk medicine. Several PANCs are recognized as weeds that interfere in the crop. Talinum paniculatum (Jacq.) Gaertn (TP) is a UPC already consumed in some regions of Brazil, but is stillunderexploited. The objective was to obtain TP stem extract and to evaluate its antimicrobial activity. The TP stem (46.8 g) was extracted with: (1) 300 mL of boiling deionized water for 5 minutes; and (2) 90 mL of ethanol hydroalcoholic solution (20/80 v/v) under constant agitation, and filtered through Whatman No. 4 filter. The minimum inhibitory concentration (MIC) against Klebsiella pneumoniae ATCC 10031, Staphylococcus aureus ATCC 29213 and Escherichia coli ATCC 43888 was evaluated by the colorimetric method by micro dilution with resazurin. The extractswere applying (100 μL; 80.0-0.039 mg/mL) in 96-well microplates with Mueller-Hinton broth. Levofloxacin (LV; 64.0-0.031 μg/mL) was used as a positive control. The minimum bactericidal concentration (MBC) was determined by applying 10 μL of the wells in standard plate count agar (PCA). For Klebsiella pneumoniae the MIC was 5 (1), 10 mg/mL (2) and < 0.031 g/mL (LV); the MBC was 40 (1), 10 mg/mL (2) and 8 g/mL (LV). For Staphylococcus aureus the MIC was 10 (1), 5 mg/mL (2) and 2 g/mL (LV); the MBC was 20 (1), 40 mg/mL (2) and 4 g/mL (LV). For Escherichia coli the MIC was 40 (1), 10 mg/mL (2) and 0.25g/mL (LV); the MBC was 40 (1), >80 mg/mL (2) and 8 g/mL (LV). In contrast, Menezes et al. found that the extracts (water; ethanol/water 70/30; methanol/water 70/30 v/v) of the TP leaf at concentrations of 455 and 650 mg/mL had no antimicrobial effect for Escherichia coli, Staphylococcus aureus and Salmonella Thyphimurium. The obtained extracts showed antimicrobial potential standing out as a viable alternative natural antimicrobial.