Mycobiota, mycotoxigenic fungi, and citrinin production in black olives

Abstract

Olives have been reported to be a poor substrate for the production of aflatoxins (Mahjoub and Bullerman, 1987; Eltem, 1996; Leontopoulos et al., 2003). However Yassa et al., (1994) isolated A. flavus and A. parasiticus from black table olives in Egypt, from which nine strains of A. flavus and five strains of A. parasiticus were found to produce aflatoxin B1 on olive paste. Toussaint (1997) and Daradimos et al. (2000) found aflatoxin B1 in olive oil samples at levels of 5-10 μg/kg and 3-46 ng/kg respectively. Mahjoub and Bullerman (1987) found that mixing olive paste with yeast extract sucrose agar caused a moderate increase of aflatoxin B1 production compared with yeast extract sucrose medium alone, and that heat and sodium hydroxide treatments stimulated growth and aflatoxin production in olives. However, Leontopoulos et al. (2003) found higher levels of aflatoxin produced in olives sanitized with chlorine than in those sterilized by autoclaving.