Abstract:

Solvent extraction was used to extract antimicrobial substances from clove against a Penicillium strain preserved in our laboratory, and their activity was evaluated by paper disc method. The clove extracts obtained using water, 60% ethanol, nhexane or acetone were tested for their diameters of inhibition zone and ethanol was the selected solvent due to the smallest diameter of inhibition zone. This was followed by the optimization of diameter of inhibition zone of ethanol extract from clove using single factor and orthogonal array design methods. The results showed that the optimal conditions for improved extraction of antimicrobial substances from clove were as follows: ethanol concentration 60%, solid-to-liquid ratio 1 g:12 mL and extraction temperature 60 ℃ for a reflux extraction duration of 2 h.

Key words: clove, extraction, Penicillium species, antimicrobial effect