Heat Treatment Reduces Bacterial Contamination of Medicinal Plants Grown in A Community Garden

Abstract

The verification of microorganisms that indicate contamination of medicinal plants cultivated in vegetable gardens is fundamental to contribute and improve the conditions and management of the garden, providing safer and healthier food for the consumer population. The study aims to evaluate the bacteriological quality of Cymbopogon citratus, Aloysia citriodora, Plectranthus barbalus, Aloe vera (L.) Burm. F., Sedum dendroideum, and Peumus boldus cultivated in community gardens. Six samples were randomly collected from each plant and sent to the Laboratory of Veterinary Preventive Medicine and Public Health at Universidade Paranaense-UNIPAR, for bacteriological analysis (aerobic mesophilic microorganisms, total coliforms and coliforms at 45ºC. The cold extract (room temperature) of the medicinal plants evaluated, the Plectranthus barbalus had the highest mean for aerobic mesophiles (1.26 CFU/g x 106) and the Cymbopogon citratus second highest mean for aerobic mesophiles (9.80 CFU/g x 105). In the coliform count at 45°C, the highest mean was found in the Aloysia citriodora (2.90 CFU/g x 103) and it presented the second lowest mean for coliforms at 45°C (0.63 CFU/g x 103) and was zero for total coliforms. Regarding the hot extract (95°C-100°C) of the medicinal plants evaluated, a significantly higher aerobic mesophiles count was found for Aloysia citriodora when compared with Aloe vera (L.) Burm. F., Sedum dendroideum and Peumus boldus, not differing statistically from Cymbopogon citratus and Plectranthus barbalus. It was found that medicinal plants are contaminated but, since they are indicated as teas (infusion), they are safe for their consumers because the risk of bacteriological contamination can be considerably eliminated or reduced due to the boiling process.

Keywords

• aerobic mesophiles
• food safety
• microbiology
• public health
• total coliforms