Safe food: Signs to look for in beans

Over the years, there have been several beans ‘scare’ and even fatalities following the consumption of meals prepared from cowpea, popularly known as beans.

In many cases, the ‘illness’ or death resulting from eating cooked beans is confined to the realm of superstition; some believe the victims would have been poisoned or suffering from witchcraft spells.

Dr. Abdoulaye Tahirou, Agricultural Economist at the International Institute of Tropical Agriculture (IITA), Ibadan argues it is a tricky thing identifying chemicals used for preservation in cowpea, by physical observation, presented for sale.

“On the issue of pesticides in cowpea, it is very hard to tell if cowpea has been treated with chemical just by looking.” However, he informs that there are some signs, which one can look for:
• well preserved cowpea comes with a “smell” and
• very well preserved cowpeas may have some powdery substances. Of these, it is not what a consumer can pick up by cursory physical examination.

Only recently, at a scientific forum in Lagos, a farm manager said one of the ways to identify beans good enough to buy is if the grain has got holes arising from weevil attack. He said if the grain was treated with chemical after harvest, there would most likely be no holes in the seed.

Dr. Tahirou shared his perspective on this: “ Typically when cowpea have holes, it is a good indication that chemicals were not used or at least, not too much.” However, He thinks this is in the past because with hermetic storage (including PICS bags, Jerrycans, drums, well-sealed clay pots, etc), one can preserve cowpea without any chemical addition (they will have no holes).

Scientists say that certain chemicals, if taken by humans, are harmful. It is most likely that the so-called ‘killer beans’ is associated with the chemicals used for storage.

The problem with this kind of killer ‘grain’ is when produce merchants cannot differentiate well between chemicals for storage and that for field treatment. It is suspected that sometimes, they are erroneously used interchangeably.

On the whole, there is need for increased public education to deal with such food safety issues. For instance, most chemicals have periods to observe before food treated with them could be eaten and many people lack this knowledge.
PICS Bags

Due to the challenge of insufficient drying and storage, grains can be exposed to potential risk of microbiological contaminants and production of toxins, Purdue Improved Crop Storage (PICS) bags was introduced and promoted in the country.

PICS bags form a barrier against the entry of oxygen and the leakage of carbon dioxide; the resulting conducive moisture condition over a storage period helps to retain the original status of the produce.

Tahirou revealed that farmers in rural Nigeria have adopted these bags for use in storing cowpea, but the big merchants are complaining about the additional work and the hand tying required for PICS bags.