Antifungal effect of Cinnamomum cassia and Litsea cubeba on selected species of Penicillium genera at aw 0,98 and 0,93

Abstract

Većina hrane i stočne hrane podliježe mikrobiološkoj kontaminaciji tijekom pripreme, skladištenja i distribucije. Eterična ulja i njihovi sastojci postaju sve popularniji kao antimikrobna sredstva. Eterična ulja su aromatične uljne tekućine dobivene iz biljaka različitim metodama. Njihov antimikrobni učinak ovisi o sadržaju, koncentraciji i interakcijama među glavnim aktivnim sastojcima, kao i među sastojcima hrane. Zadatak rada bio je istražiti antifungalni učinak eteričnih ulja Cinnamomum cassia i Litsea cubeba te timola i propil galata na odabrane vrste plijesni: Penicillium aurantiogriseum, P. brevicompactum i P. chrysogenum. Određena je minimalna inhibitorna (MIK) i minimalna fungicidna (MFK) koncentracija eteričnih ulja. Nadalje, određen je učinak eteričnih ulja u inhibiciji linearnog rasta kolonije plijesni tijekom uzgoja na krumpirovom agaru s glukozom (PDA) pri različitim vrijednostima aktiviteta vode (aw). Najveći fungicidini učinak pokazalo je ulje Cinnamomum cassia, zatim Litsea cubeba i timol, dok propil galat nije djelovao inhibitorno na rast plijesni. Veće koncentracije ispitanih eteričnih ulja i sastojaka smanjuju rast svih ispitanih Penicillium vrsta. Cinnamomum cassia i Litsea cubeba produžavaju lag fazu pri nižem aw (0,93), dok timol posjeduje bolji inhibitorni učinak na linearan rast kolonija plijesni kod višeg aw (0,98).Most of the food and feed are microbiological contaminated during preparation, storage and distribution. Essential oils and thier components are becoming increasingly popular as naturally occurring antimicrobial agents. Essential oils are aromatic oily liquids obtained from plants by different methods. Their antimicrobial effect depends on composition, concentration and interactions between the main active compounds, as well as food components. The aim of the study was to test the antifungal activity of essential oils of Cinnamomum cassia and Litsea cubeba and thymol and propyl gallate on selected mold species: Penicillium aurantiogriseum, P. brevicompactum and P. chrysogenum. Minimal inhibitory (MIC) and minimal fungicidal (MFC) concentrations of essential oils were tested. Furthermore, the effect of essential oils in the inhibition of linear growth of mold colonies during cultivation on potato dextrose agar (PDA) at different values of water activity (aw) was tested. The most potent antifungal effect showed Cinnamomum cassia oil, then Litsea cubeba and thymol, while propyl gallate had no antifungal effect on tested species. Higher concentrations of tested essential oils and compounds reduced the growth of all tested Penicillium species. Cinnamomum cassia and Litsea cubeba extend the lag phase at lower aw value (0,93), while thymol has better inhibitory effect on linear growth of mold colonies at higher aw value (0,98)