Chapter 13 - Mycotoxins in Seeds and Nuts

Abstract

This chapter explores the presence of mycotoxins in seeds and nuts. Mycotoxins are toxic secondary metabolites produced by fungi, whose natural occurrence in agricultural staples can cause acute and/or chronic intoxication symptoms in both humans and animals at low concentration levels. Although other mycotoxins can occur, the most reported mycotoxins in nuts and seeds are aflatoxins, a group of related bisfuranocoumarin compounds produced mainly by Aspergillus flavus and A. parasiticus. Fungal growth and aflatoxin production depend on biological (susceptible crop) and environmental factors, with the emphasis on regional climatic conditions during plant development and crop harvest. The most prominent means of humans' exposure to aflatoxins is through ingestion of contaminated food, but other routes, such as inhalation and contact, must be considered. Exposure by inhalation can result from handling contaminated materials or from airborne fungal components. The disease resulting from exposure to aflatoxins, called aflatoxicosis, can be classified as acute or chronic. In addition to corn and spices, peanuts, cottonseed, Brazil nuts, pistachios, and copra are included in the group of commodities with a high risk of aflatoxin contamination. Aflatoxins are highly heat stable, but heat inactivation in contaminated food has been attempted. Taking into account that strict guidelines on aflatoxin contamination have been imposed, constant monitoring throughout the food-producing chain is essential to minimize health risks and comply with trade requirements.