[Surveillance on contamination of total aflatoxins in corn, peanut, rice, walnut and pine nut in several areas in China]

Abstract

Objective: To realize the contamination of total aflatoxins in corn, peanut, rice, walnut and pine nut in China, and provide the base data for establishing a China tolerance limit standard and an international control practice for total aflatoxins.

Methods: The samples of corn, peanut, rice, walnut and pine nut from Chongqing, Fujian, Guangdong, Guangxi, Hubei, Jiangsu, Shanghai and Zhejiang provinces and municipalities were collected randomly from markets, with the totally 284 samples. The samples were grounded and added to acetonitrile/water mixture. After filtering, the extract was transferred into a purifying column and pressed slowly. Then the purified liquid was derivatized with trifluoroacetic acid (TFA) and detected by using a high performance liquid chromatography (HPLC).

Results: There was 70.27% corn having been detected out an average level of aflatoxins of 36.51 microg/kg and the highest level was 1098.36 microg/kg. At the same time, there was 14.86% corn exceeding the China national tolerance limit. In peanut, the aflatoxins detected rate was 24.24%. The average level was 80.27 microg/kg and the highest level was 437.09 microg/kg. While there was 3.03% peanut exceeding the China national and Codex tolerance limits. All of the rice, walnut and pine nut samples met the China tolerance limit for aflatoxins.

Conclusion: Corn and peanut might be the severely contaminated foods with aflatoxins in China. The aflatoxin B(1) in foods might be can not delegate the contamination of aflatoxins completely. Surveillance of total aflatoxins in foods suggested an actual need of establishing the China national and international standards for total aflatoxins.