Evaluation of the susceptibility of Ziziphus jujuba var. spinosa fruit to aflatoxin contamination and infection of aflatoxigenic fungus based on ripening stages and fruit parts

Abstract

Aflatoxin contamination in medicinal herbs raises a big concern. The susceptibility of Ziziphus jujuba var. spinosa fruit to aflatoxin contamination and infection of aflatoxigenic fungus was evaluated based on ripening stages and fruit parts. Fruits or their parts at different ripening stages, contaminated with aflatoxin by inoculating Aspergillus flavus, were used for investigating the relationship of aflatoxin contamination with ripening stages, fruit parts, and fungal mycelial growth by aflatoxin analysis and microscopic study. The results showed 1) the intermediate ripening stages were highly susceptible to aflatoxin contamination, 2) when each fruit part was inoculated with A. flavus, aflatoxin concentration in the seed part was highest among the fruit parts, and 3) the hilar region is the area of the fungal mycelial penetration within the seed. This study suggests that it is better to store the fruits in a ripe and intact state for preventing aflatoxin contamination during storage.