Antifungal effect of preservatives on fungi of Penicillium genera in vitro and in situ conditions

Zadatak rada bio je ispitati antifungalni učinak Na-benzoata i K-sorbata na odabrane vrste plijesni: Penicillium aurantiogriseum, P. expansum i P. italicum pri različitim pH vrijednostima. Natrijev benzoat je sol benzojeve kiseline. Proizvodi se reakcijom natrijevog hidroksida s benzojevom kiselinom. Natrijev benzoat je konzervans koji se najviše koristi u proizvodnji gaziranih pića, voćnih sokova, marmelada, ukiseljenog povrća, kiselih krastavaca i začina gdje je, zbog niske pH vrijednosti moguć rast plijesni. Kalij sorbat je sol sorbinske kiseline. Primarno se koristi kao konzervans u proizvodnji hrane i pića. Djeluje inhibitorno na rast plijesni i kvasaca u mnogim namirnicama kao što su sir, vino, jogurt, bezalkoholna pića, pekarski proizvodi, itd. Važno djelovanje kalijevog sorbata je i povećanje trajnosti proizvoda. Prema dosadašnjim rezultatima eksperimenta, utvrđeno je kako se snižavanjem pH vrijednosti i antifungalni učinak spojeva povećava. Oba spoja su podjednako učinkovita na odabrane vrste plijesni. Ispitana je inhibicija linearnog rasta kolonija plijesni pri koncentracijama od 50, 100 i 200 ppm Na – benzoata i K – sorbata pri pH vrijednosti 5,12 i 4,50. K – sorbat učinkovitije inhibira linearni rast kolonije u usporedbi s Na – benzoatom.The aim of the study was to determine antifungal activity of sodium benzoate and potassium orbate on selected fungal species: Penicillium aurantiogriseum, P. expansum and P. italicum at various pH values. Sodium benzoate is the salt of benzoic acid. It can be produced by reaction of sodium hydroxide with benzoic acid. Sodium benzoate is a preservative most widely used in carbonated drinks, fruit juices, jams, conserved vegetables, pickles and condiments where, at acidic environment, inhibits fungal contaminants. Potassium sorbate is the potassium salt of sorbic acid. It is primary used as a food preservative. It inhibits molds and yeasts in many food products, such as cheese, wine, yogurt, soft drinks and baked goods. Important effect of potassium sorbate is to maintain and prolong quality of products. The experimental results suggest increased antifungal activity of tested compounds at lower pH values. Both compounds inhibit fungi at similar concentrations. Linear inhibition of fungal growth at 50, 100 and 200 ppm of Na – benzoate and K – sorbate at pH 5,12 and 4,50 has been tested. Preliminary results suggest stronger inhibitory potential of K – sorbate, compared to Na – benzoate