Aflatoxins: Risk, Exposure and Remediation

Abstract

Aflatoxins family includes a great number of lipophilic molecules produced by aerobic microscopic fungi belonging to the genus Aspergillus. The chapter describes their chemical structure, chemical and physical properties, and aspects related to their presence in food and commodities. Aflatoxins presence in food is considered a real and severe risk to consumers for their toxicity. Aflatoxins levels and frequency of foods natural contamination as reported in the scientific literature are briefly analyzed. Focus is given to the different foodstuffs that may be at risk of contamination by Aspergillus and the subsequent accumulation of aflatoxins in the food chain. Bioavailability and bioaccessibility of aflatoxins will be discussed considering that these unwanted molecules can be assumed by the humans with the diet. Bioaccessibility, that deals with the fraction of micro-nutrients released from the food matrix during digestion and gastro-intestinal available for absorption, will be discussed with reference to aflatoxins bioaccessibility of during the digestion process, considering the relationships between the food matrix and its influences on aflatoxins fate. Bioavailability of the aflatoxins assumed from the diet depends on their stability during digestion, since they are released from the food matrix (bioaccessibility) and on the efficiency of their passage through the gastro-intestinal mucosa. The term bioavailability includes the concepts of availability to the absorption, metabolism, distribution of nutrients to tissues and bioactivity and indicates the fraction of micro-nutrients absorbed by the body and the speed with which these molecules are absorbed and made available at their site of action. Despite of the practical difficulties in measuring the distribution and bioactivity of aflatoxins on a specific human body organ, the bioavailability is the fraction of an oral dose of a compound or precursor of an active metabolite that reaches the bloodstream. Bioaccessibility includes the entire sequence of events that take place during the digestion of food material that can be assimilated by the body through the epithelial cells of the gastro-intestinal mucosa. Aflatoxins are often present in very small amounts or in traces and, for this reason, a part of the chapter addresses the advanced new chromatographic and spectrometric methods described in the literature and applied to research, that can reveal, even in trace amounts, aflatoxins in biological fluids as free form or as by-products, e.g. non-covalent adducts

Draft Genome Sequence of an AflatoxigenicAspergillusSpecies,A. bombycis

“…B aflatoxins are generally considered more potent mycotoxins than G aflatoxins, but both are considered serious carcinogenic compounds and their purpose or function in nature has yet to be determined (Santini and Ritieni, 2013). Aspergillus bombycis (NRRL 26010) was characterized and associated with the genus’ Section Flavi in 2001 (Peterson et al 2001).…”

Aflatoxin B1: Chemistry, Environmental and Diet Sources and Potential Exposure in Human in Kenya

“…Aflatoxin B1: Chemistry, Environmental and Diet Sources and Potential Exposure in Human… DOI: http://dx.doi.org/10.5772/intechopen. 88773 Aflatoxin B1 (AFB1) is a secondary metabolite produced by Aspergillus flavus and Aspergillus parasiticus when environmental factors are favourable [13,14]. It has also been characterized as a biological toxin.…”

Mycotoxins, Food and Health

“…Copyright: © 2017 Fernandes TH, et al In parts of the world where food supply is limited, drastic regulatory measures to lower mycotoxin standards would lead to food shortages and to higher prices. The observation made during the outbreak of aflatoxin hepatitis in western India in 1974 that "starving to death today by not consuming contaminated food in order to live a better life tomorrow is not a practical option" is relevant even after 40 years [35]. Thus, any preventive measures must be pro-poor, well focused, and cost-effective.…”