Inhibitory Potential of Eucheuma denticulatum (N.L.Burman) F.S. Collins & Hervey Against Selected Foodborne Pathogens

Abstract

Seaweed is reported to have antimicrobial properties that can possibly prevent the food from microbial invasion and spoilage. Eucheuma denticulatum (N.L.Burman) F.S. Collins & Hervey is a very abundant seaweed in Leyte province, wherein it is a common part of the human diet. The common problem in food handling, especially street food, is the fast rate of spoilage due to improper handling and packaging. One way of preventing the incidence of food infection and intoxication due to improper packaging of food is the use of packaging material that can inhibit microbial growth. The study was undertaken to determine the antimicrobial potential of E denticulatum against common food pathogens. Six pathogenic bacteria – namely, Bacillus cereus, Staphylococcus aureus, Salmonella typhi, Escherichia coli O157:H7 – plus a yeast (Candida albicans) and a mold (Aspergillus flavus) were used as test organisms of the study. Agar well diffusion assay was used to test the inhibitory potential of E denticulatum extract against the selected pathogens. The ethanolic extract exhibited inhibitory potential against the test microorganisms except for Gram- positive bacteria B cereus and S aureus. The extract is more effective against Gram-negative bacteria S typhi and E coli. C albicans exhibited the highest mean zone of inhibition of 16.11 mm at 75% extract concentration, and A flavus has the least zone of inhibition of 2.78 mm. The observed inhibitory action of the ethanolic extract is a promising indication that E denticulatum is a potential source of bioactive compounds that can be used as a natural food preservative.