Hidden Threats: Exploring Aflatoxin Contamination in Groundnuts

Aflatoxins are a type of mycotoxin that are primarily produced by Aspergillus flavus and Aspergillus parasiticus. These fungi are widely known to grow on crops like groundnuts, corn, and cottonseeds, and thrive in warm and humid conditions. They pose such a serious threat to human health that the World Health Organisation (WHO) declared it a Group 1 carcinogen. Carcinogens are described as substances or agents that are capable of causing cancer. 

Aflatoxins were first discovered and termed as dangerous in the early 1960s when they were identified as the causatives of ‘Turkey X’ disease, an epidemic that was the root of deaths of numerous turkey poults, ducklings, and chicks which were fed diets predominantly comprised of peanuts that traced back to South America. 

Aflatoxins are of four types primarily, namely: B1, B2, G1 and G2. Through experiments done on test species and human epidemiological studies by scientists at WHO, it was observed that Hepatitis B Virus (HBV) was a critical contributor to the potency of aflatoxins. 

Through statistics it is noticed that 1 in 4 cases of liver cancer in patients is a result of these toxins, specifically, Aflatoxin B1. They are also known to cause impaired growth and immune system suppression, hepatocyte anisocytosis and apoptosis. 

These mycotoxins cause not only health problems, but also deeply impact the economical aspect. They are known to cause grave economical losses to farmers, traders and the food industry. In India, the acceptable amount of aflatoxins in groundnuts is drawn to 30 ppb (Parts Per Billion) as stated by the Food Safety and Standards Authority of India (FSSAI). Upon inspection, groundnuts that cross the limit are denied for sale and consumption. From both international and national laws, products that do not fit the category cause pricy deprivations due to the wasted labour and transportation costs. To add, extensive labour goes into the farming, cultivation and extraction of groundnuts. 

So, how is the situation managed? 

There are multiple ways to reduce aflatoxins in groundnuts. To start off, using human assistance to handpick mouldy, damaged and split nuts helps in eliminating groundnuts that have a high concentration of these toxins. This method requires extreme persistence, commitment and time, yet is still not favoured due to possible human error. 

Storage of groundnuts is to be carefully monitored. Dry, room temperate conditions are requires to minimise their growth since most mycotoxins are known to reproduce in dark, damp places. The implementation of correct planting, irrigation, and pest management practices adds to the security and reduces the likelihood of mould growth. It is crucial to note the right maturity time of the nuts.

This image shows a batch of mouldy nuts, likely infested with aflatoxins. 

India has established regulatory levels of aflatoxins in food, for instance, 10 microgram/kg for ready-to-eat foods and dried figs, 30 microgram/kg for spices and oilseeds (groundnuts fall into this category) and 15 microgram/kg for cereal and its derived products. 

Control of mycotoxins can be of two types- prevention of fungal growth and toxin production or decontamination of existing mycotoxins in consumables. 

Plants and herbal compounds like chlorophyll and its derivatives can be used as biocontrol. Although these methods are partially beneficial, they are not cost effective. Specific herbs and their extracts have been known to act as inhibitors of mould growth, in turn toxin production. A few examples are garlic, turmeric and neem. Ammonia, sodium bisulfite, peroxide, acids, bases and gases are effective in the chemical detoxification of aflatoxins, however, they may ruin the palatability of the foods.    

Biological methods include a cell wall derivative of Saccharomyces cerevisiae that shows incredible binding ability with familiar aflatoxins. Along with these, mineral clays like bentonites, zeolites and aluminosilicates are also used to absorb mycotoxins. 

Aflatoxins can be detected in laboratories through various tests. These include kits using Enzyme-Linked Immunosorbent Assay (ELISA), Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography (HPLC). 

Lastly, it is imperative for consumers to know about the levels of aflatoxins in their foods. Before buying a product, it is advised to always look it up and research about it, which in turn would cause them to make smart choices. The increasing awareness of mycotoxins and their effects aids to a healthier, longer life and better future.