COMPARATIVE ANTIMICROBIAL AND ANTIOXIDATIVE PROPERTIES OF TWO VARIETIES OF GARLIC (Allium Sativum)

Abstract

The prime objective of the study is to determine and compare the nutritional and therapeutic values of two varieties of garlic. The fresh garlic bulbs were dried, milled (about 100g) and extracted with 300ml ethanol (80%) in a soxhlet apparatus for 24 hours, after extraction, the solvent was filtered and freeze dried. Control plates were also set up and standard antibiotics, tetracycline at 0.02gm were incubated. The garlic extract was subjected to chemical, phytochemical, mineral, vitamins, antimicrobial and antioxidative analysis. Standard methods were used to determine the proximate nutrient composition and atomic absorption, spectrophotometer was used to determine the mineral and vitamin compositions. The results showed that both varieties are predominantly high in mineral and vitamin compositions. Antimicrobial activity of extracts of Allium sativum (garlic) was evaluated against fifteen different test microorganisms namely Escherichia coli, Salmonella Typhi, Staphylococcus aureus, Bacillus cereus, Listeria monocytogen,Opalina brucei, Entamoeba histotylitical, Candida albican etc. Brown garlic extract showed antimicrobial activities against many organisms such as C. perferigens, Bacillus cereus, S. typhil, B .cerius. white garlic extract showed antibacterial activities against Staphylococcus aureus, E. coli and, L monocytogens. In addition, agar well diffusion method showed higher zone of inhibition when compared with the zone of inhibition produced by the spice of same concentration against the test microorganism by disk diffusion method. antibiotics, Tetracycline; which produced the highest zone of inhibition of 10±0.001 against E.coli and the lowest zone of inhibition of 7.00±0.004 against Staphilococcus typhi. Zone of inhibition for both fungi and parasites were predominantly revealed to be high in brown garlic extracts, garlic has been a favorite additive in food for many years in various cultures. However, using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging methods to determine the antioxidant activity of raw garlic extract shows a color change from deep violet to yellow, indicating antioxidant activity. Thus, raw garlic can be a source of antioxidant based on the results of the DPPH scavenging. The study has therefore revealed a high nutritional qualities and possible therapeutic effects more importantly in brown garlic, which is locally sourced and relatively chea