Samples of sterile long grain white rice were inoculated with different inoculum levels of Aspergillus flavus subsp parasiticus spores and incubated at 25°C. Ergosterol content, mold count and aflatoxin production were determined. Ergosterol was determined using a method that consisted of methanol-hexane extraction, saponification and quantification using HPLC with UV-detection. At low inoculum levels mold spores and ergosterol were not detected until the third day of incubation. Generally aflatoxin B1 followed the same trend as ergosterol. At high inoculum levels ergosterol and mold spore counts were detectable before aflatoxin B1. There was no clear pattern between aflatoxin G1 production and ergosterol content. Ergosterol appears to be a sensitive early indicator of low levels of fungal activity and aflatoxin production in rice.
All Science Journal Classification (ASJC) codes
- Food Science