Comparative study on the effect of temperature and water activity on Aspergillus flavus and Aspergillus carbonarius isolates growth and mycotoxin production on a chili powder medium

Cogent Food & Agriculture

Thanapoom Maneeboon¹  Chananya Chuaysrinule¹  Warapa Mahakarnchanakul¹ 

[1] Kasetsart University;

关键词: temperature;    water activity;    growth;    aflatoxin;    ochratoxin a;    aspergillus;    response surface methodology;   

DOI  :  10.1080/23311932.2020.1782097

来源: DOAJ

【 摘 要 】

This study was aimed at determining the effect of temperature and water activity (aw) on the radial growth of Aspergillus flavus and A. carbonarius isolated from dried chili and their production of aflatoxin B1 (AFB1) and ochratoxin A (OTA), respectively. The isolates were grown on a synthetic chili-based medium, and growth and mycotoxin production were studied following a central composite design. The diameter of each colony was measured, and mycotoxins were extracted from the medium after 7 days of incubation at each different combination of temperature and aw. The analysis of variance results showed that temperature, aw, and their interaction had significant effects on growth and mycotoxin production. Response surface analysis showed that both strains were able to grow within a wide range of temperatures (22.93–37.07°C) and aw values (0.885–0.984), but production of AFB1 and OTA was not detected at 37.07°C or at aw below 0.900. The most favorable growth conditions for A. flavus were within a temperature range of 25–30°C and aw higher than 0.970, and maximum AFB1 production occurred at 22.93°C and aw of 0.984. For A. carbonarius, optimum growth and OTA production were observed at 22.93°C and aw of 0.970–0.984. Our results may be useful for controlling the growth of post-harvest mold in chili and preventing mycotoxin contamination of dried chili.

【 授权许可】

Unknown