Antibacterial activity of fresh and dried samples of Allium sativum Linn and Zingiber officinale Roscoe against Salmonella enterica and Escherichia coli on raw chicken meat / Siti Noor Aliza Apandi

The study of the antimicrobial potency of the two aromatic vegetables Allium sativum Linn and Zingiber officinale Roscoe has been investigated against the two most common food spoilage bacteria, Escherichia coli and Salmonella enterica. The antibacterial activity was determined by the disc diffusion method. Kirby-Bauer method was used to determine the susceptibility of the bacteria toward the aqueous extract of A.sativum and Z.officinale. The average inhibition zone of 300 mg/ml fresh A.sativum aqueous extracts of against the E.coli is 14.2 mm (σ=0.76) and 15.3 mm (σ=0.76) for S.enterica.At 100 mg/ml dried A.sativum aqueous extract its recorded the average of the inhibition zone of against E.coliis 6.7 mm (σ=0.29)and 5.5 mm (σ=1.32)for S.enterica. The average inhibition zone of 300 mg/ml of fresh Z.officinale against E.coli is 6.8 mm (σ=0.76) and 6.0 mm (σ=1.50) for S.enterica. The average zone of inhibition of 100 mg/ml of dried Z.officinale against E.coli is 12.2 mm (σ=0.29) and 11.5 mm (σ=0.50) for S.enterica. The minimum inhibitory concentration (MIC) of fresh A.sativum, dried A.sativum, fresh Z.officinale, and dried Z.officinale was recorded at 9.37 mg/ml, 50.00 mg/ml, 12.50 mg/ml, and 75.00 mg/ml respectively. These concentrations were used to disinfect the chicken meat for 90 minutes of exposure. Theenumeration of bacteria using pour plate method were performed every 30 minutes. The total colony count of untreated chicken meat were recorded at μ=67.25 per gram. The average total colony count after 60 minutes of fresh A.sativum, dried A.sativum, fresh Z.officinale, and dried Z.officinale extracts exposures were 1.6, 30.3, 17.6 and 9.0 respectively. At 90th minutes, the average total plate count of fresh A.sativum, dried A.sativum, fresh Z.officinale, and dried Z.officinale extracts exposures were 18.6 CFU/ml, 23.3 CFU/ml, 36.3 CFU/ml and 55.6 CFU/ml respectively. Overall study stated fresh A.sativum aqueous extract has the potential as natural antibacteriocidal agent. From this comparative study of these natural preservative, it was conclude that the fresh A.sativum is more effective than the dried A.sativum, and dried Z.officinale were stronger antibacterial than the fresh Z.officinale extracts. This comparative showed the fresh A.sativum extract is most effective, which inhibit the bacterial growth at lowest concentration of 9.37 mg/ml. It is recommended to increase the concentration of the bioactive compound, for both aromatic vegetables to obtain the higher antibacterial activity, for a better control of the bacterial growth.