|
چکیده
|
Garlic (Allium sativum) is historically involved in human medicine and food. This plant is widely cultivated almost all over the world. Several ecotypes of garlic is grown and cultivated in Iran, including Rasht purple garlic that is belong to Persian star garlic with purple strips and big bulbs. Garlic due to having bioactive sulphur compounds, have some biological properties and different ecotypes exert variable level of these properties. In this study total phenolic compounds of aqueous, ethanol, methanol, hexane, chloroform, boiled, brewed and total-extract (garlic juice) of Rasht purple garlic peels and edible parts were measured. The antioxidant activity of each extract was determined by using DPPH assay and antibacterial activity against food pathogens bacteria such as: S. aureus (~ 26 mm), Y. enterocolitica (~ 20.2 mm), E. coli (~ 16.8 mm), S. typhimurium (~ 16.7 mm), S. dysentery (~ 16.7 mm), E. faecalis (~ 13.3 mm), P. aeroginosa (~ 11 mm), & L .monocytogenes (0 mm) was determined by use of minimum bactericidal concentration (MBC) and well-method. Although garlic juice was found to have good antioxidant and antimicrobial activity in all experiments but it was observed that polar solvents had higher potential to extract more bioactive compounds from garlic. Boiling temperature deactivates both antibacterial and antioxidant compounds, but brewed extract showed high antibacterial activity. It seems that antioxidant compounds of garlic are more sensitive to high temperature while a combination of high temperature and short time help to extract higher amount of antibacterial compounds or changes these compounds in such a way to increase their antibacterial activity. However no antibacterial activity was observed for extracts from peel but Rasht purple garlic peel found to have approximately 40% higher antioxidants than Gorgan white garlic. Finally, according to sensory analysis results obtained from panelists, adding 0.5% of garlic juice to Doogh lead to produc
|