Determination of antimicrobial activity of spices using well diffusion method

Začinsko bilje radi svog kemijskog sastava i sadržaja biološki aktivnih spojeva ima vrlo pogodan učinak na zdravlje čovjeka pa je i interes za njegovu moguću primjenu u poboljšanju sigurnosti hrane povećan. Fenolni spojevi su sekundarni metaboliti biljka koji imaju ulogu u obrani biljke od vanjskih utjecaja, a upravo njima se prepisuju antioksidativna i antimikrobna svojstva. U ovom radu analiziran je sadržaj ukupnih fenola 17 odabranih začinskih biljaka te im je određena antimikrobna aktivnost. U tu svrhu pripremljeni su UVZ/vodeni ekstrakti i određen antimikrobni učinak na četiri patogene bakterije, dvije Gram pozitivne (Staphylococcus aureus, Listeria monocytogenes) i dvije Gram negativne (Salmonella enterica i Escherichia coli). Za određivanje antimikrobnog potencijala korištene su dvije metode: metoda difuzije u jažicama i minimalne inhibitorne koncentracije (MIC). Korelacija između sadržaja ukupnih fenola i antimikrobne aktivnosti 17 začinskih biljaka nije utvrđena, a najbolje rezultate pokazao je ekstrakt češnjaka (MIC=17,94 mg GAE/L, zona inhibicije >25mm) koji je imao sadržaj ukupnih fenola od 179,44 mg GAE/L. Ostali ekstrakti koji su pokazali antimikrobnu aktivnost bili su: klinčić, kadulja, koromač, limun, maslina, ružmarin, peršin, celer.The chemical structure and content of biologically active compounds fromspices have a beneficial effect on human health, thus the interest of thier possible application in improvement of food safety has increased. Phenolic compounds are secondary metabolites of plantsthat play a protection role from extrinsic factors and show the antioxidant and antimicrobial properties. In this theses the content of total phenols of extractsfrom 17 selected spices was analyzed and their antimicrobial activity was determined. For this purpose, UVZ/aqueous extracts were prepared and antimicrobial potentian on four pathogenic bacteria, two Gram positive (Staphylococcus aureus, Listeria monocytogenes) and two Gram negative (Salmonella enterica, Escherichia coli) was determined using two methods: well diffusion method and the minimum inhibitory concentration method (MIC).No correlation was found between total phenols content and antimicrobial activity of 17 spices, garlic extract (MIC = 17.94 mg GAE/L, inhibition zone>25 mm) was found to have the best results, which had a total phenol content of 179.44 mg GAE/L. Other extracts that showed antimicrobial activity were: clove, sage, fennel, lemon, olive, rosemary, parsley, celery