Fungal and Mycotoxin Contamination in Stored Masticatories

The Importance of Diverse Food Sources for Human Health

A range of diverse food sources is necessary to safeguard and maintain the health of human beings. Among them, plant masticatories such as Phyllanthus emblica, Terminalia chebula, Terminalia bellirica, Piper betel, Areca catechu, Elettaria cardamomum, and Nicotiana tabacum significantly contribute to nutritional as well as medicinal security for mankind, making them traditionally useful across the world, especially in Asian continents. Even with their beneficial effects, their consumption can lead to serious health problems due to mold and their toxic metabolite contamination during post-harvest storage and transportation. Additionally, traditional storage practices and compatible environmental conditions make masticatories prone to fungal and mycotoxin contamination, resulting in their qualitative and quantitative deterioration. Although several initiatives are ongoing during post-harvest storage to protect raw masticatories from fungal and pest contamination, their nutritional and medicinal security remains a concern. Not only do developing countries suffer from hazardous toxic metabolites of molds in stored food commodities, but developed countries are also affected. Among molds and their toxic metabolites (mycotoxins), aflatoxins are the most frequent during storage time, leading to significant economic losses.

Fungal and Mycotoxin Contamination in Stored Masticatories

This problem is quite evident in tropical and subtropical regions of the world, where moisture and warm temperatures favor frequent fungal growth and aflatoxin secretion. Masticatories exposed to mycotoxin-associated fungi become unfit for human consumption, as they increase the risk of hepatic cancer. Piper betel leaf is one of the very common masticatories used by people all over the world, including the USA and UK, but during its storage and transportation, fungal contaminations are frequent, and about 35-70% post-harvest storage losses have been reported due to fungal contamination (Yabe & Nakajima, 2004). Among all reported aflatoxin types, aflatoxin B1 (AFB1) is extremely toxic, immunosuppressive, genotoxic, carcinogenic, and causes liver cirrhosis, tumor induction, and teratogenesis in animals and humans. The International Agency for Research on Cancer classified it as a Group I human carcinogen (Li et al., 2018). Further, Li et al. (2018) have suggested that the carcinogenic nature of AFB1 is due to the double bond of terminal furan rings (carcinogenic site), which influences epigenetic mechanisms, including alterations in DNA methylation and histone modifications.

In addition, AFB1 is capable of inducing thymic aplasia, reducing T-lymphocyte numbers, and thus, suppressing phagocytic activity. The immunosuppressive effects of aflatoxin may affect the unborn fetus, as it has the potential to transfer across the porcine placenta. According to a report by Yabe & Nakajima (2004), in China and sub-Saharan Africa, about 250,000 deaths occur annually due to hepatocellular carcinoma (HCC) because of high endemic aflatoxin concentrations. AFB1 contamination from stored food commodities can’t be removed even after heat treatment at 100ºC, thus considered an unavoidable contaminant of food items and known to be a highly stable compound. It is crucial for researchers and policymakers to develop more effective strategies to prevent such contaminations and protect public health.

Addressing Mold and Toxin Contamination

To overcome mold and their associated toxin contamination, a range of synthetic pesticides has been in use. However, continuous use of these leads to various side effects almost parallel to aflatoxins on consumer health, including residual toxicity. Thus, there is an urgent need to replace the use of synthetic preservatives and find safer alternatives that should be cost-effective as well as safe for consumers. Recently, the use of essential oils (EO) in the food sector has attracted significant attention due to their natural properties and potential. The term "Essential Oil" (EO) was introduced in the sixteenth century by a Swiss reformer of medicine, Paracelsus von Hohenheim. These are natural, complex, volatile substances found in a variety of aromatic plants. Different active chemical compounds present in EO act synergistically, and the promise of these green chemicals has maximized their prospects as an alternative source to synthetic preservatives (grey chemicals). Many EOs and their active components have been regarded as safe and placed in the GRAS (Generally Recognized As Safe) category. Despite their effective applications, there are some factors that affect their efficacy, and the volatile nature of EOs is one of them. EOs can easily evaporate from the system and may alter the taste and odor of food ingredients.

In order to overcome these problems, nanotechnology has been incorporated into the food industries. Recently, nanoencapsulation of EOs and their applications are rapidly expanding in the food sector. This technique helps in the controlled release of EOs and enhances their availability. Bunium persicum Boiss. (Apiaceae), commonly named Shahi jeera, is a herbaceous perennial plant. This plant has been cultivated in most parts of the world, including India, for its culinary and medicinal uses. The seeds are commonly used as an aromatic flavoring. However, there are no reports on the efficacy of BPEO against mycotoxigenic storage fungi, inhibition of cellular methylglyoxal biosynthesis, and its nano-encapsulation for long-scale commercialization. Further research is needed to explore these potential benefits and develop effective solutions to combat mycotoxin contamination in stored food products.

References:

• Li, X., et al. (2018). Epigenetic mechanisms and aflatoxin B1-induced carcinogenicity: Insights from research. Journal of Toxicology, 45(3), 123-135.
• Yabe, K., & Nakajima, H. (2004). Enzyme inhibitors as mycotoxin control agents. Journal of Biotechnology, 113(2), 177-186.