Comparative study on chemical composition and antibacterial activity of fenugreek (Trigonella Foenum graecum L.) and cumin (Cuminum cyminum L.) seeds

Introduction.The objective of this study was determination of the physico-chemical characteristics of fenugreek (Trigonella Foenum graecum L.) and cumin (Cuminum cyminum L.) and evaluation of their antibacterial properties against Staphylococcus aureus ATCC25923, Escherichia coli ATCC 25922 and Bacillus subtilis ATCC 6633. Materials and Methods. Different varieties of fenugreek and cumin were analyzed for their weight of 1000 seeds and germination rate. The physico-chemical analysis carried out was pH, titratable acidity, moisture, ash, total soluble solids, electrical conductivity, viscosity, proteins, fats, crude fibers, pectins, total and reducing sugars and minerals. The antibacterial activity of the extracts was evaluated by disc diffusion method against tested bacterial strains. Results and discussion. The obtained results showed that the Algerian variety of fenugreek and Syrian one of cumin seeds gave the highest weight with a value of 16.8 and 13.9 g respectively and the better germination rate with a percentage of 70%. The pH and titratable acidity of fenugreek and cumin seeds ranged from 5.6 to 6.5 and 2.8 to 3% respectively. The moisture and ash content varied from 3 to 2.8% and 3 to 7% respectively. Total soluble solids, electrical conductivity, viscosity varied from 2.8 to 5.5 degrees Brix, 18.1 to 42.8 mvs and 2.4 to 2.8 m/pa/s respectively. The analysis showed that fenugreek and cumin contained a high amount of proteins which was between 23.1 and 26.8%. On the other hand, fats ranged from 8.8 to 21%. While crude fibers, pectins varied from 5.1 to 7.9% and 1.9 to 2.8% respectively. Total and reducing sugars varied from 5.2 to 6.7%, and 0.5 to 1% respectively. According to the present data, mineral and heavy metals profile of fenugreek and cumin showed that they contain potassium as a major mineral in a maximum quantity followed by sulphur, phosphorus, calcium, magnesium, iron, zinc and boron, copper, lead, nickel, chromium, molybdenum, cobalt and cadmium. The results of antibacterial activity of methanol extract plants against three bacterial strains revealed the sensitivity of these strains to the extracts plants with DZI (Diameter Zone of Inhibition) of 21 mm, 12 mm, 18 mm for cumin and 10 mm, 08 mm, 09 mm for fenugreek respectively for S. aureus, E. coli and B. subtilis. Conclusion. The overall evaluation of this study concludes that both spices fenugreek and cumin have good chemical composition and revealed their sensitivity on the tested bacterial strains.