Abstract:

Inhibitory effects of water chestnut peel and meat extracts on bacteria were investigated using filter paper diffusion and flat-plate dilution methods. Results indicated that both extracts from water chestnut peel and meat exhibited inhibitory effects on Escherichia coli, Staphylococcus aureus, brewing yeast, baking yeast, Asperiyillus oryzae and Penicillium sp. to some extent, however, the stronger antimicrobial activity of water chestnut peel extract was observed than that of water chestnut meat extract. The minimum inhibitory concentrations (MICs) of water chestnut peel extract were 3.33% for Staphylococcus aureus and Escherichia coli, respectively; 20% for most fungi. These results reveal that water chestnut peel extract has strong inhibitory effect on both bacteria and fungi, especially on bacteria. Moreover, water chestnut peel extract also exhibited obvious inhibitory effects on bacteria in foods, which provided the potential as a natural preservative in food industry.

Key words: water chestnut peel extract, water chestnut meat extract, antimicrobial activity, minimum inhibitory concentration, food preservative