Current Developments of Analytical Methodologies for Aflatoxins’ Determination in Food during the Last Decade (2013–2022), with a Particular Focus on Nuts and Nut Products

Abstract

This review aims to provide a clear overview of the most important analytical development in aflatoxins analysis during the last decade (2013–2022) with a particular focus on nuts and nuts-related products. Aflatoxins (AFs), a group of mycotoxins produced mainly by certain strains of the genus Aspergillus fungi, are known to impose a serious threat to human health. Indeed, AFs are considered carcinogenic to humans, group 1, by the International Agency for Research on Cancer (IARC). Since these toxins can be found in different food commodities, food control organizations worldwide impose maximum levels of AFs for commodities affected by this threat. Thus, they represent a cumbersome issue in terms of quality control, analytical result reliability, and economical losses. It is, therefore, mandatory for food industries to perform analysis on potentially contaminated commodities before the trade. A full perspective of the whole analytical workflow, considering each crucial step during AFs investigation, namely sampling, sample preparation, separation, and detection, will be presented to the reader, focusing on the main challenges related to the topic. A discussion will be primarily held regarding sample preparation methodologies such as partitioning, solid phase extraction (SPE), and immunoaffinity (IA) related methods. This will be followed by an overview of the leading analytical techniques for the detection of aflatoxins, in particular liquid chromatography (LC) coupled to a fluorescence detector (FLD) and/or mass spectrometry (MS). Moreover, the focus on the analytical procedure will not be specific only to traditional methodologies, such as LC, but also to new direct approaches based on imaging and the ability to detect AFs, reducing the need for sample preparation and separative techniques.

Aflatoxins in food: Prevalence, health effects, and emerging trends in its mitigation—An updated review

“…High performance liquid chromatography (HPLC), thin layer chromatography (TLC), high performance thin layer chromatography (HPTLC), liquid chromatography–mass spectrometry (LC–MS), and gas chromatography (GC) are the techniques most frequently used for detection and quantification of aflatoxins. Even if a lot of chromatographic techniques are quite sensitive, they still need expensive equipment, labor‐intensive sample preparation, and highly skilled technicians (Abbas & Abbas, 2021; Miklós et al., 2020; Schincaglia et al., 2023; Zhang & Banerjee, 2020).…”

“…Mycotoxin analysis has long recognized and benefited from the potential advantages of the LC–MS approach. As per the m/z (mass to charge ratio) of the analytes, an inherent character that offers more precise detection based on the molecular weight of the target analyte, simultaneous analysis of multiple mycotoxins may be achievable with LC–MS analyses (Schincaglia et al., 2023). The superior sensitivity in quantification, preciseness in detection, and quantity of mycotoxins that may be examined in a single study have all been used to characterize the influence of the contemporary LC–MS technique (Ouakhssase et al., 2019).…”

“…AF commercial analysis does not frequently employ GC; nonetheless, as there are other straightforward and less expensive chromatographic methods available. Nevertheless, the GC approach is not widely employed in aflatoxin analysis because of a few drawbacks, such as substantial variation in reproducibility and repeatability, memory effects from prior samples, nonlinearity of calibration curves, and drifting responses (Schincaglia et al., 2023; Zhang & Banerjee, 2020).…”

“…High performance liquid chromatography (HPLC), thin layer chromatography (TLC), high performance thin layer chromatography (HPTLC), liquid chromatography-mass spectrometry (LC-MS), and gas chromatography (GC) are the techniques most frequently used for detection and quantification of aflatoxins. Even if 50 -FOOD SAFETY AND HEALTH a lot of chromatographic techniques are quite sensitive, they still need expensive equipment, labor-intensive sample preparation, and highly skilled technicians(Abbas & Abbas, 2021;Miklós et al, 2020;Schincaglia et al, 2023;Zhang & Banerjee, 2020).4.1.1 | Thin layer chromatographyIt is one among the popular separation methods for AF identification.Since 1990, TLC has been considered the preferred method by the Association of Official Analytical Chemists. It is made up of an inert substance termed the matrix-a plastic or glass and a solid immobilized stationary phase that may include silica, cellulose, or alumina.The acetonitrile, methanol, and water mixture that makes up the mobile phase is what propels the sample through the stationary phase(Salisu et al, 2021).…”

“…It is possible to identify AFs at minimum concentrations of 5 pg using HPTLC.4.1.3 | High-performance liquid chromatographyIt is one among the widely used chromatographic methods to separate and identify organic molecules. HPLC is in use to estimate about 80% of all chemical substances worldwide(Namjoo et al, 2016;Schincaglia et al, 2023). High automation, high sensitivity, and high precision characterize the HPLC method for estimating AFs.…”