Ten solvents were used to extract phytochemicals from the peel of Carica papaya cv. Sekaki/
Hong Kong to evaluate antibacterial activities and determine chemical composition of Carica
papaya cv. Sekaki/Hong Kong seeds. The antibacterial activities of ten solvent extracts were
tested against 14 microorganisms vis Shigella sonnei, Salmonella typhimurium, Escherichia
coli, Salmonella enteritidis, Vibrio vulnificus, Vibrio parahaemolyticus, Proteus mirabilis,
Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Corynebacterium diphtheria,
Clostridium perfringens, Streptococcus pneumoniae and Bacillus subtilis using disk diffusion
test (DDT). The Carica papaya seed of ACN and MeOH extracts inhibited 11 microorganisms,
indicating their broad spectrum activity. The disk diffusion test exhibited moderate and clear
inhibition on C. diphtheria, S. pneumonia, B. subtilis and C. perfringens. MeOH extract
inhibited S. enteritidis, V. vulnificus, P. mirabilis and B. cereus with the lowest MIC at 11.25
mg/mL each, thus was chosen as the best extract. The hierarchy of extract potency can be
ranked as MeOH > acetone > ACN > CHCL3 > hexane > DE = PE > EtOH > DCM based
on clear and moderate inhibition and the lowest MIC. TPC and TFC of the extracts ranged
between 4.83 to 22.59 mg GAE/g DW and 1.32 (water) and 17.15 mg QE/g DW respectively.
The GC/MS analysis of MeOH extract identified potential antibacterial compounds such as
isothiocyanatomethyl benzene, 9-octadecenoic acid, hexadecanoic acid and β-sitosterol. The
Carica papaya seed cv. Sekaki/ Hong Kong possessed significant antibacterial activities when
extracted by different solvents in particular MeOH solvent.