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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Poultry Microbiological Safety and Processing Research Unit » Research » Publications at this Location » Publication #358859
Research Project: Novel Pre-harvest Interventions and Alternatives to Antibiotics to Reduce Foodborne Pathogens

Location: Poultry Microbiological Safety and Processing Research Unit

Title: Effect of extraction procedure on yield, phytochemical profile and antibacterial activity of fenugreek seed (trigonella foenum-graecum) crude extracts

Author
item CHALGHOUMI, RAJA - University Of Carthage, Tunisia
item MABROUKI, S - University Of Carthage, Tunisia
item ABDOULI, H - University Of Carthage, Tunisia
item Line, John

Submitted to: Legume Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/16/2020
Publication Date: 8/5/2020
Citation: Chalghoumi, R., Mabrouki, S., Abdouli, H., Line, J.E. 2020. Effect of extraction procedure on yield, phytochemical profile and antibacterial activity of fenugreek seed (trigonella foenum-graecum) crude extracts. Legume Research. (43):718-722. https://doi.org/10.18805/LR-511.
DOI: https://doi.org/10.18805/LR-511

Interpretive Summary: Post-weaned rabbits are sensitive to digestive disorders, some of which may be aggravated by enteric bacteria such as Escherichia coli. Fenugreek (Trigonella foenum-graecum) is a medicinal plant known for its various pharmacological properties, including its anti-bacterial activity. The purpose of this study was to optimize the extraction parameters of components from fenugreek seed possessing an antibacterial effect. The optimum conditions for the extract were determined based on the extract yield by varying three parameters: solvent (water, methanol or ethanol), substrate-solvent ratio (1:5 or 1:10) and extraction time (24h, 48h or 72h). Results showed that solvent and extraction time had an effect on yield of extract. The results obtained in the present study indicate that although using water as a solvent gives the best extraction yield, fenugreek seed extract prepared with methanol showed the best antibacterial effect against the targeted bacterial strain. Additional work is needed to assess in vivo potencies and toxicological profiles of the methanol extract before its incorporation into feedstuff of post-weaned rabbits can be recommended as a dietary approach to prevent digestive disturbances during this critical period.

Technical Abstract: The purpose of this study was to optimize the extraction parameters of components from fenugreek seed possessing an antibacterial effect. The optimum conditions for the extract were determined based on the extract yield by varying three parameters: solvent (water, methanol or ethanol), substrate-solvent ratio (1:5 or 1:10) and extraction time (24h, 48h or 72h). Results showed that solvent and extraction time had an effect on yield of extract. Optimum conditions for highest yield of extract (270,78 mg/g) are as follows: solvent (water), substrate-solvent ratio (1:10), and extraction time (72 hours). Regardless of the solvent used, the extracts at the highest yield were analyzed qualitatively for phytocomponents and their bacterial growth inhibitory effect was assessed by (1) measuring the diameter of the inhibition zone (IZ) using an agar-well diffusion method and (2) determination of the minimum inhibition concentration (MIC) using a microtitre plate-based antibacterial assay incorporating resazurin. Phytochemical screening of the extracts revealed the presence of the major compounds known to have antibacterial activity such as tannins and flavonoids in the aqueous and methanol extracts. The methanol extract exhibited an antibacterial effect at the four concentrations tested (2.5; 5; 10 and 20 mg/ml) with an IZ diameter ranging from 8.46±2.25 mm up to 27.65±1.32 mm. The ethanol extract showed a moderately growth inhibitory effect (12 mm = IZ = 20 mm) when tested at a concentration equal to or above 10 mg/ml. The aqueous extract displayed the weakest antibacterial effect (IZ= 9.50±1.15) and only at the highest concentration tested (20 mg/ml). The aqueous extract had the highest MIC value (10 mg/ml), while the methanol extract displayed the lowest MIC value (1.25 mg/ml). The ethanol extract possessed a moderate growth inhibitory effect with a MIC value equal to 5 mg/ml. The results obtained in the present study indicate that although using water as a solvent gives the best extraction yield, fenugreek seed extract prepared with methanol showed the best antibacterial effect against the targeted bacterial strain.