Tackling aflatoxin in groundnut

The permitted level of aflatoxin in groundnut for human consumption, according to international standards, is 4 parts per billion (ppb) in the European Union and 20 ppb in the US.

India, being second-largest producer of groundnut, faces difficulties in accessing these markets as the level of aflatoxin on Indian groundnut is high and is considered unfit for human consumption. In accordance with Agmark standards, the permitted level of aflatoxin in India is 30ppb.

Owing to high food safety and animal and plant health concerns, many SPS (sanitary and phyto-sanitary) notifications have been issued against India by several countries over the last few years. This has resulted in exports of groundnut oil to many developed and developing countries shrinking.

Being dependent on imported oils for domestic consumption, augmented with increasing demand for edible oil in India, the lack of market access due to aflatoxin in groundnut has not been given due importance.

The question which remains in the mind of an aware consumer that if the level of aflatoxin in groundnut is so high that it is unfit for human consumption in many countries, then how come it is fit for Indian consumers?

According to Indian Council of Medical Research (ICMR)-Lucknow, 21 per cent of groundnut in India is unfit for human consumption due to aflatoxin. Another study conducted by Icrisat reveals that the level of aflatoxin in Indian groundnut is 40 times more than permissible limits.

Aflatoxin is a sort of poison produced by the mould Aspergillus flavus which leads to severe health effects on humans and animals alike. Aspergillus flavus is the most common specie in Africa and Asia, highly toxic group of mycotoxins.

Aflatoxin accumulating fungi can infect groundnut during the production season as well as during post-harvest handling. Pre-harvest infection by Aspergillus flavus and consequent Aflatoxin contamination is more important in the semi-arid tropics, especially when drought occurs just before harvest.

Drought-stressed plants lose moisture from pods and seeds; physiological activity is greatly reduced. Both factors increase susceptibility to fungal invasion. Poor harvesting and storage conditions can lead to rapid development of the fungi and thus high toxin can be produced.

India has now developed agricultural practices and technologies which can reduce the extent of aflatoxin to permitted levels.

Mere adoption of good varieties and good agricultural practices (GAPs) can help reduce the level of aflatoxin to 20 ppb. Breeding efforts have focused on reducing groundnut maturity periods to escape end-of-season drought, and the emphasis has been on the identification of short-duration farmer preferred lines with resistance to or tolerance of Aspergillus.

Among the recommended practice at production stage, applications of lime alone can reduce aflatoxin contamination by 72 per cent, while application of farm yard manure reduces aflatoxins by 42 per cent under field conditions. When combined, aflatoxin contamination can be reduced by up to 84 per cent. Harvesting at appropriate stage, adoption of proper drying method, reducing kernel moisture to the level of 8 per cent, etc prevents the accumulation of aflatoxin significantly.

The Directorate of Groundnut (Junagarh) recommends some of the measures such as crop rotation with onion or garlic, selection of short- and medium-term varieties, advanced sowing, supplemental irrigation during end of the season, etc to reduce aflatoxin.

The response of farmers towards adoption of these practices, however, has been poor. Farmers are even not aware of the health issues related to aflatoxin consumption and are reluctant to take a serious note of it due to unavailability of premium price for aflatoxin-free groundnut.

Lack of awareness about the recommended GAPS has also been a major factor inhibiting the probability of adoption of the recommended practices. There is need for conducting mass level sensitisation programme for farmers as well as consumers to tackle the issue right from farm level to till processing and consumption.

Consumers’ awareness about aflatoxin can lead to demand for aflatoxin-free (permissible limit) groundnut and thus farmers may also fetch better price for taking the pain of improving their field and storage level practices.

The writers are associated with National Institute of Agricultural Marketing, Jaipur. Views are personal.