Recent Advances in Mycotoxin Analysis and Detection of Mycotoxigenic Fungi in Grapes and Derived Products

Mycotoxins are secondary metabolites of filamentous fungi that can cause toxic effects in human and animal health. Most of the filamentous fungi that produce these mycotoxins belong to four genera, namely, Aspergillus, Penicillium, Fusarium, and Alternaria. Mycotoxigenic fungi, along with mycotoxins, create a constant and serious economic threat for agriculture in many terms, counting product losses due to crop contamination and food spoilage, as well malnutrition when considering nutritional quality degradation. Given the importance of robust and precise diagnostics of mycotoxins and the related producing fungi in the grape food chain, one of the most important agricultural sectors worldwide, the present review initially delivers a comprehensive presentation of mycotoxin reports on grape and derived products, including a wide range of commodities such as fresh grapes, raisins, wine, juices, and other processed products. Next, based on worldwide regulations’ requirements for mycotoxins, and referring to the relative literature, this work presents methodological approaches for mycotoxin determination, and stresses major methods for the detection of fungal species responsible for mycotoxin production. The principle of function and basic technical background on the available analytical and molecular biology techniques developed—including chromatography, mass spectrometry, immunochemical-based assays, biosensors, and molecular assays—is briefly given, and references for their application to grape and derived product testing are highlighted.

Quality evaluation of Alpinia oxyphylla after Aspergillus flavus infection for storage conditions optimization

In the storage of Alpinia oxyphylla, growth of mildew (especially toxic fungi, such as Aspergillus flavus) is a potential safety risk. Few reports have investigated how A. oxyphylla storage conditions impact mold growth or how mold growth impacts the bioactive components of A. oxyphylla. In this study, sterilized A. oxyphylla samples were contaminated by artificial inoculation of A. flavus spores. The main chemical components and aflatoxin levels in the infected A. oxyphylla samples were characterized. Central composite design-response surface methodology was used to study the effects of different temperature and humidity of storage conditions on the fungal growth in A. oxyphylla and accumulation of aflatoxins. The results showed that aflatoxins levels can be minimized by storing samples at temperatures below 25 °C and with humidity less than 85%. Additionally, we found that the yield and composition of volatile oil in A. oxyphylla exhibited small changes due to mold growth. However, polysaccharide content reduced remarkably. Temperatures below 25 °C and humidity below 85% were the best storage conditions to preventing A. oxyphylla from becoming moldy. Our results provide the theoretical basis for future studies the effects of storage conditions and mold growth on the quality and safety of traditional Chinese medicines (TCMs).

Dynamic variation of bioactive compounds and aflatoxins in contaminated Radix Astragali during extraction process

BACKGROUND

Although increasing attention has been paid to the health threat caused by mycotoxins in commodities such as food or medicines, mycotoxin transfer processes from crude material to products have raised little concern so far. Radix Astragali is a commonly used edible and medicinal herbal plant that is susceptible to contamination with aflatoxins from Aspergillus flavus. There have been no studies on mycotoxin transfer into pharmaceutical preparations or derivative products.

RESULTS

To facilitate the aflatoxin reduction and bioactivity retention, the dynamic variations of aflatoxins as well as herbal compounds, namely calycosin-7-glucoside, astragaloside and formononetin, in Radix Astragali contaminated by A. flavus during water decoction and ethanol refluxing treatments were evaluated simultaneously by an ultra-fast liquid chromatography-triple quadrupole linear ion trap mass spectrometry method. After the extraction processes, although the amount of alfatoxins was reduced remarkably, aflatoxin residuals in preparation still exceed recommended limits, manifesting the great need to establish a limit for aflatoxins in herbal extractions or derivative products. Meanwhile, due to the hydrolysis of glucoside, water decoction period should be no longer than 4 h.

CONCLUSIONS

This investigation would benefit from the determination of the dynamic variation of aflatoxins in infected herbs in preparation treatments, in order to further develop aflatoxin limits in herbal preparations.

Developments in mycotoxin analysis: an update for 2013-2014

This review highlights developments in the determination of mycotoxins over a period between mid-2013 and mid-2014. It continues in the format of the previous articles of this series, emphasising on analytical methods to determine aflatoxins, Alternaria toxins, ergot alkaloids, fumonisins, ochratoxins, patulin, trichothecenes and zearalenone. The importance of proper sampling and sample preparation is briefly addressed in a dedicated section, while another chapter summarises new methods used to analyse botanicals and spices. As LC-MS/MS instruments are becoming more and more widespread in the determination of multiple classes of mycotoxins, another section is focusing on such newly developed multi-mycotoxin methods. While the wealth of published methods during the 12 month time span makes it impossible to cover every single one, this exhaustive review nevertheless aims to address and briefly discuss the most important developments and trends.