Aflatoxins: Risk, Exposure and Remediation

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

Determination of trichothecenes and zearalenones in grain cereal, flour and bread by liquid chromatography tandem mass spectrometry

Although analytical methods have been already reported for legislated mycotoxins as trichothecenes and zearalenone (ZON) separately, we describe the optimization of a simple and rapid multimycotoxin method for the determination of a total of 12 mycotoxins simultaneously, nine trichothecenes (NIV, DON, FUS-X, DAS, 15-AcDON, 3-AcDON, NEO, HT-2, T-2 T2), and zearalenone and its metabolites (ZON, a-ZOL, b-ZOL), of different origin (wheat, oat, barley and spelt) and in three different products where these substance can be present (grain, flour and bread) reach the food chain and cause toxic effect either in humans or animals. The extraction procedure was based on a mixture of acetonitrile/water (84/16, v/ v), which provided the highest recoveries and the lowest matrix effect. DON-d1 was used as internal standard (I.S.) which helped to compensate the significant matrix effect observed for some matrices, and to obtain high success in the method validation and to reach the parameters compiled in Commission Decision, 2002/657/EC. Analytes were determinate by liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS). Relative recoveries obtained were higher than 70% for the studied mycotoxins the four cereal. Good linearity (r2 > 0.992) was obtained and quantification limits (2.5–25 ng/g) were below European regulatory levels. Repeatability, expressed as relative standard deviation, was always lower than 11%, whereas interday precision was lower than 11% for the developed method

Mycotoxins: An Under-evaluated Risk for Human Health

Mycotoxins are secondary toxic metabolites produced mainly by fungi belonging to the Aspergillus, Penicillium, Fusarium, Alternaria, and Claviceps genera. These moulds can colonize agricultural crops and produce mycotoxins during pre- and post-harvest practices, processing, and storage. Animals fed with feed contaminated with mycotoxins may be a natural and unwanted bioenhancer way to transfer mycotoxins, eventually metabolized, to animal-derived food addressed to humans. The natural occurrence of mycotoxins, also a low concentration, in food may cause adverse health effects in humans, rarely showing acute symptoms but the chronic exposure causes problems ranging from gastrointestinal and kidney disorders to immune deficiency and to develop some types of cancers. Human exposure to mycotoxins can happen by eating directly contaminated foods or through contaminated animal products. This alternative entry of mycotoxin into the human food chain is a signal of animals fed with contaminated feed. The exposure danger to mycotoxins can be monitored by following the biotransformation product occurrence in tissues and biological fluids, and these data are needed to evaluate their potential risk for humans, in particular for weak subpopulations like babies, children, old, or pressed by food security troubles. In this regard, the main aim of this volume is to evaluate the occurrence of mycotoxins and other contaminants in food, nutraceuticals, and biological fluids in order to ensure human safety. To guarantee effective consumer safety, reliable methods have been validated for the analysis of contaminants in various matrices. In addition, the risk associated with the assumption of contaminated food was assessed. Risk characterization is an indispensable aspect to safeguard public health, which helps to identify risks threatening consumers

Bioaccessibility of Deoxynivalenol and its natural co-occurrence, with Ochratoxin A and Aflatoxin B1 in italian commercial pasta

Cereals products for direct human consumption are rarely contaminated by moulds, unlike raw materials, which are often infected, either in the field or during storage. In this study, 27 samples of dried pasta characterised by size, packaging and marketing intended for young children consumption were collected and analysed by liquid chromatography (LC) and liquid chromatography– tandem mass spectrometry (LC–MS/MS) for Deoxynivalenol (DON), Ochratoxin A (OTA) and Aflatoxin B1 (AFB1) determination. The samples that showed the highest amounts of one of the mycotoxins were cooked for 10 min, digested with an in vitro gastrointestinal protocol and bioaccessibility values were calculated. Seven of the 27 samples exceeded from 120% to 225% the legal limit of 200 lg/kg for DON fixed for processed cereal-based baby foods by an European Regulation; all the collected samples were under the OTA legal limit (0.05 lg/kg) fixed by the European Regulation and no sample was contaminated by AFB1 over the instrumental limit of detection of 0.10 lg/kg. The mean value of gastric bioaccessibility verified for the DON resulted of 23.1%, whereas mean duodenal bioaccessibility was 12.1%

The Nutraceutical Properties of “Pizza Marinara TSG” a Traditional Food Rich in Bioaccessible Antioxidants

Italian gastronomy experiences have ever-enhancing fame around the world. It is due to the linkage between taste and salubriousness commonly related to Mediterranean foods. The market proposes many types of pizza to suit all palates. In this work, the antioxidant potential of the "pizza “marinara” included in the register of traditional specialties guaranteed (TSG) was determined. ABTS method evaluated the antioxidant activity of the pizza homogenized. In vitro digestion models estimated the intestinal and gastric bioaccessibility of the main antioxidant compounds (lycopene and phenolics). To our knowledge, this is the first study to provide the content, antioxidant potential, and bioaccessibility of the antioxidants (polyphenols and lycopene) contained in the traditional pizza “marinara TSG”. Our results showed that the "pizza marinara TSG" had polyphenols concentration, lycopene level, antioxidant activity, and bioaccessibility of phenolic compounds and lycopene better than other similar pizzas. They confirmed the nutritional importance of traditional preparations and established the functional potential of "pizza marinara TSG" as a food rich in bio-accessible antioxidants

The nutraceutical properties of "pizza marinara TSG" a traditional food rich in bioaccessible antioxidants

Italian gastronomy experiences have ever-enhancing fame around the world. It is due to the linkage between taste and salubriousness commonly related to Mediterranean foods. The market proposes many types of pizza to suit all palates. In this work, the antioxidant potential of the "pizza “marinara” included in the register of traditional specialties guaranteed (TSG) was determined. ABTS method evaluated the antioxidant activity of the pizza homogenized. In vitro digestion models estimated the intestinal and gastric bioaccessibility of the main antioxidant compounds (lycopene and phenolics). To our knowledge, this is the first study to provide the content, antioxidant potential, and bioaccessibility of the antioxidants (polyphenols and lycopene) contained in the traditional pizza “marinara TSG”. Our results showed that the "pizza marinara TSG" had polyphenols concentration, lycopene level, antioxidant activity, and bioaccessibility of phenolic compounds and lycopene better than other similar pizzas. They confirmed the nutritional importance of traditional preparations and established the functional potential of "pizza marinara TSG" as a food rich in bio-accessible antioxidants

Influence of the heat treatment on the degradation of the minor Fusarium mycotoxin beauvericin

Beauvericin (BEA) is a bioactive compound produced by the secondary metabolism of several Fusarium strains and known to have various biological activities. This study investigated the degradation of the minor Fusarium mycotoxin BEA present in the concentration of 5 mg/kg in a model solution and in different crispy breads produced with different flours typologies (corn, hole, wheat, durum wheat, soy and rice) during the heat treatment carried out in an oven at three different temperatures of 160, 180 and 200 C and at 3, 6, 10, 15 and 20 min incubation. The concentration of the bioactive compound studied, analyzed with the technique of the liquid chromatography tandem mass spectrometry (LCeMS/MS), decreased in the experiment carried out in the model solution from 2.89 0.13 mg/kg of the assay at 160 C for 3 min until the complete degradation at 200 C during 20 min incubation. In the experiments carried out using the crispy breads prepared with different kind of flours, as system to simulate a food preparation, the percentage of BEA degradation, resulted variable from 20 to 90%, with no a significative differences showed in the use of the different flour matrices. Also a metabolite of the thermical degradation of the mycotoxins BEA was identified using the LCeMS in the full scan mode

Occurrence of Mycotoxin in Farro Samples from Southern Italy

The occurrence of nine mycotoxins and of contamination by pre- and postharvest fungal pathogens of cereals was investigated in samples of stored Triticum monococcum L., Triticum dicoccon Schrank (emmer), and Triticum spelta L. (spelt). In Italy, all three species are collectively referred to as farro. The samples examined were harvested in summer 2000 from eight different sites in southern Italy. Conventional fluorimetric and diode array-based high-performance liquid chromatography (HPLC) analyses and HPLC-mass spectrometry analyses were used to identify fumonisin B1 in five samples (up to 70.00 microg/ kg), ochratoxin A in seven samples (up to 4.07 microg/kg), and beauvericin in three samples (up to 4.44 mg/kg). Enniatin B was detected in one sample (30.00 microg/kg), but no zearalenone or fusaproliferin was found. Deoxynivalenol and aflatoxins were not evaluated. The potentially mycotoxigenic fungal species detected were Alternaria alternata, Fusarium proliferatum, Fusarium tricinctum, Penicillium verrucosum, and Penicillium chrysogenum. This is the first report of the natural occurrence of mycotoxins in farro samples

Dietary strategies to counteract the effects of mycotoxins: a review.

We reviewed various dietary strategies to contain the toxic effects of mycotoxins using antioxidant compounds (selenium, vitamins, provitamins), food components (phenolic compounds, coumarin, chlorophyll and its derivatives, fructose, aspartame), medicinal herbs and plant extracts, and mineral and biological binding agents (hydrated sodium calcium aluminosilicate, bentonites, zeolites, activated carbons, bacteria, and yeast). Available data are primarily from in vitro studies and mainly focus on aflatoxin B1, whereas much less information is available about other mycotoxins. Compounds with antioxidant properties are potentially very efficacious because of their ability to act as superoxide anion scavengers. Interesting results have been obtained by food components contained in coffee, strawberries, tea, pepper, grapes, turmeric, Fava tonka, garlic, cabbage, and onions. Additionally, some medicinal herbs and plant extracts could potentially provide protection against aflatoxin B1 and fumonisin B1. Activated carbons, hydrated sodium calcium aluminosilicate, and bacteria seem to effectively act as binders. We conclude that dietary strategies are the most promising approach to the problem, considering their limited or nil interference in the food production process. Nevertheless, a great research effort is necessary to verify the in vivo detoxification ability of the purposed agents, their mode of action, possible long-term drawbacks of these detoxification-decontamination procedures, and their economical and technical feasibility

In-vitro screening ofSaccharomyces strains for ochratoxin A removal from liquid medium

The aptitude of twentySaccharomyces sensu stricto strains to remove ochratoxin A from a synthetic medium containing 1.1 ng/mL, about half of the European Community limit, was evaluated using four to six mg of biomass (wet weight)/mL. Seven satins show high levels of ochratoxin A removal, 0.72-1.10 ng/mL, equivalent to 66–100% of the available toxin, and unitary removing ativity of 14.31–27.24 pg/mg of biomass. Further research will be carried out to study the mechanism of OTA removal and to confirm the ability of the most efficacious strains ofSaccharomyces sensu stricto to remove OTA from contaminated wort and grape must during alcoholic fermentation