STUDIES ON PHYTOCHEMICAL AND ANTIMICROBIAL PROFILE OF HOP (Humulus lupulus L.) EXTRACTS ON FOOD PATHOGENS (Escherichia coli AND Salmonella sp.)

In addition to their importance in beer brewing, hops have been used in traditional herbal medicines as antimicrobial agents against pathogens. This study is aimed at investigating the phytochemical and antimicrobial profile of hop (Humulus lupulus L.) extracts on food pathogens (Escherichia coli and Salmonella species). The bacterial food pathogens were isolated and identified from soymilk by phenotypic characterization. Phytochemical screening of the extracts was carried out using standard methods. The antibacterial assay was performed using agar well diffusion method. The pathogenic isolates recovered from soymilk were Escherichia coli and Salmonella spp. The preliminary phytochemical screening revealed that flavonoid and saponin were abundantly present; alkaloid, steroids, tannin and glycosides were moderately present while terpenoids and phenol were slightly present in the hop (Humulus lupulus L.) extract. The results of antibacterial assay showed minimum inhibitory concentration (MIC) for Escherichia coli at 200mg/ml concentration with zone of inhibition 2.00mm while minimum inhibitory concentration (MIC) for Salmonella spp. at 100mg/ml concentration with zone of inhibition 1.00mm. The extract obtained from hops flowers showed little antimicrobial activity against the tested food pathogens (Escherichia coli and Salmonella spp.). The results indicated that this plant considered mainly as raw material in brewing industry has antibacterial and antioxidant potential.