Mould growth on black table olives and prevention by sorbic acid, methyl-eugenol and spice essential oil.

Thirty-two mould strains were isolated from Turkish-style black table olives. Four of these isolates were identified as Aspergillus ochraceus, two as A. niger, 16 as Penicillium clavigerum and 10 as P. expansum. Mould growth was evaluated on olives treated with 500 ppm sorbic acid, 1000 ppm methyl-eugenol and 1500 ppm çörtük spice (Echinophora sibthorpiana Guss.) essential oil. Olives inoculated with A. parasiticus NRRL 2999 and P. clavigerum were also examined. All samples were stored at 28 degrees C, 15 degrees C and 5 degrees C for 60 days. The lower the temperature, the more time it took the mould to initiate mycelium and spore development. Most inhibition of growth was obtained using sorbic acid in all cases and especially at low temperatures, followed by methyl-eugenol and essential oil. Decreased inhibition was observed in noninoculated olives. Inhibitory effect of used agents was higher in olives inoculated with P. clavigerum than in olives inoculated with A. parasiticus.