Effect of water content on the growth of A. flavus and Aflatoxin M1 accumulation during storage of fresh walnut in Xinjiang

Abstract

Objective: To improve the storage safety of Xinjiang fresh walnut. Methods: Xinjiang "Xin 2" thin-skinned walnut was used as material, sterile water was inoculated as a control group, and Aspergillus flavus was inoculated as an experimental group. The Aspergillus flavus isolated and purified from naturally moldy walnut was artificially inoculated into Xinjiang thin-skinned fresh walnut with different water content （10%, 15%, 20%, 25%, 30%） to investigate the growth and toxicity of Aspergillus flavus. Results: The water content of walnut which was suitable for the growth of Aspergillus flavus and the secretion of Aflatoxin M1 was 15%. With the increase of walnut water content, the growth of Aspergillus flavus increased first and then decreased, but the growth of each water content was different, and the growth of Aspergillus flavus was proportional to the content of Aflatoxin M1. Conclusion: The water content of raw materials is closely related to the growth of Aspergillus flavus and the content of Aflatoxin M1 produced.

Keywords

• aspergillus flavus
• aflatoxin m1
• water content
• thin-skinned walnut
• fresh walnut