摘要 : Some plants have the intrinsic ability to stall the spoilage activities of spoilage organisms in foods. This ability is dependent on factors such as the solvent of extraction and plant source. It is in this light that preliminary ... 展开 Some plants have the intrinsic ability to stall the spoilage activities of spoilage organisms in foods. This ability is dependent on factors such as the solvent of extraction and plant source. It is in this light that preliminary studies on the antimicrobial properties and various methods of extraction of Carica papaya (pawpaw) seeds, Citrus paradisi (grapefruit peel) and Piper guineense (black pepper) seeds were evaluated against eleven bacteria associated with fresh catfish spoilage using the cup-plate diffusion method. These bacteria are Proteus mirabilis, Escherichia coli, Staphylococcus aureus, Acinetobacter sp., Klebsiella pneumoniae, Klebsiella oxytoca, Pseudomonas lundensis, Bacillus subtilis, Bacillus megaterium, Citrobacter freundii and Enterobacter cloacae. Cold water, hot water and ethanol were the different extraction solvents used; while the extract concentrations evaluated were 0.1, 0.2, 0.3, 0.4 and 0.5 g mL^-1, respectively. Generally, hot water extraction method of the plant materials was most effective (p<0.01) with the highest mean zone of inhibition of 4.42+or-0.38 mm followed by ethanol extraction (3.55+or-0.47 mm). The most susceptible bacteria was Enterobacter cloacae with the highest mean zone of inhibition of 22.6+or-3.50 mm. This investigation indicates that the antimicrobial compounds in grape peel and black pepper are best liberated when extracted with ethanol; while those of pawpaw are best extracted with hot water.Digital Object Identifier http://dx.doi.org/10.3923/jfas.2013.142.147 收起