| dc.description.abstract | Aims: To establish the most suitable extraction method for sweet lupine seeds and to determine
minerals, phenolic content, flavonoids, antioxidant activity and antimicrobial activities.
Study Design: Known and standard experimental procedures are employed.
Place and Duration of Study: Department of Chemistry, Bethlehem University- Palestine, from
January 2019 to March 2019.
Methodology: Seeds were ground and extracted by Soxhlet extractor using ethanol with different
percentages (50%, 60%, 70%, 80% and 95%). Sodium, potassium and ferrous ion content were
determined. Resistance to bacteria was performed against Escherichia coli and Staphylococcus
aureus, while antioxidant activity was determined by FRAP method. Two types of flavonoids were
measured: Flavonones and dihydroflavonols via the reaction with 2,4-dinitrophenylhydrazine.
Phenolics were determined by the Folin-Ciocalteu method.
Results: 50% ethanol resulted in the highest extract residue (18.6%) while 70% and 60% showed
the lowest content (10.0% for both). 80% ethanol extracted sample showed the highest content for
sodium (56.51 mg Na/g extract), while 60% and 50% ethanol extracts showed the highest content
of potassium (2.25 and 2.33 mg K/g extract, respectively). The maximum concentration of ferrous
ion was obtained with 70% ethanol (6.854 mg Fe+2/g extract). 95% ethanolic extract showed the
highest antioxidant activity (20.24 mg FeSO4/g extract). Similar results were obtained for total
phenolic content and flavonoids: 24.60 mg gallic acid/g extract for phenolics and 116.02 mg rutin/g
extract for flavonoids. Extracts showed no bacterial activity against both types of bacteria used.
Conclusion: 95% ethanol extracted samples showed the highest antioxidant activity and the
highest flavonoids and phenolic content. Sweet lupine extract did not perform any antimicrobial
activity against both Gram positive and Gram negative bacteria. | en_US |
