The production of cyclopiazonic acid by Penicillium commune and cyclopiazonic acid and aflatoxins by Aspergillus flavus as affected by water activity and temperature on maize grains.

The combined effects of water activity (a(w)) and temperature on mycotoxin production by Penicilium commune (cyclopiazonic acid - CPA) and Aspergillus flavus (CPA and aflatoxins - AF) were studied on maize over a 14-day period using a statistical experimental design. Analysis of variance showed a highly significant interaction (P ≤ 0.001) between these factors and mycotoxin production. The minimum a(w)/temperature for CPA production (2264 ng g(-1) P. commune, 709 ng g(-1) A. flavus) was 0.90 a(w)/30 °C while greatest production (7678 ng g(-1) P. commune, 1876 ng g(-1) A. flavus) was produced at 0.98 a(w)/20 °C. Least AF (411 ng g(-1)) was produced at 0.90 a(w)/20 °C and most (3096 ng g(-1)) at 0.98 a(w)/30 °C.