Effect of moisture on aflatoxins production of isolated Aspergillus flavus from Vietnamese peanut ☆

Aflatoxins are known as toxic chemical compounds having serious effect on animal’s and human’s health. Aflatoxins are prevalent in various foods in Vietnam. This study is conducted to demonstrate the effect of moisture on Aflatoxins production in peanut. Peanut kernel with 6%, 8%, 10%, 12% and 14% moisture are injected with 103CFU/g of strain A. flavus TUHT115 then packaged in sealed PVC bag and kept at 25oC in 4 months. The mold growth and Aflatoxin (AF) production are checked every two weeks. As the results, peanut sample with 6% and 8% moisture are not contaminated with AF after 4 months study; the samples with moisture 10%, 12% and 14% are detected to be contaminated with AF after 2 weeks study and only AFB1 & AFB2 are detected in studied samples. AFB1 contaminated level is higher than maximum permissible level (8g/kg) as regulated in QCVN 8-1:2011/BYT after 4th week and total AF is higher than maximum permissible level (15g/kg) after 6th week. This study also revealed that peanut moisture content of level from 10% and more are accumulated AFB1 and total AF have linear relative with moisture and time.