April 21, 2022

Ensuring safe, aflatoxin-free produce using Dry Card technology

Staple Crops

Soy and Oil Seeds

Nigeria

Since time immemorial, farmers have been sun-drying food in readiness for storage. They however rely on ancient practices, such as biting, chewing, or looking at the general appearance of food products to ascertain that they are well-dried for short or long-term storage. This can be attributed to the fact that most smallholder farmers do not have access to a cost-effective, accurate way of assessing the moisture level of dried food before storage

Limitations of the traditional method: a white-sorghum farmer’s perspective

Using traditional methods to measure moisture content has often resulted in food loss due to aflatoxin and damage to the produce.

Sun-drying is a labor-intensive activity that involves taking the grains out of the storehouse and spreading them on gunny bags under direct sunlight. In the evenings, they are either covered with a waterproof bag or taken back to the store just in case it rains at night. Unfortunately, even after this rigorous task, there is still no guarantee that the produce is well dried.

Mr. Abbas Ismail is a 39-year-old smallholder sorghum farmer from Kuki Town, Kaduna state. Asked about how he measures the moisture content of his grains after harvest, this is what he had to say:

I check if the sorghum grains are well dry by rubbing a sample on my palms. I also bite and crack the grain using my teeth to tell if they are sufficiently dried. However, I have encountered losses when off-takers reject my produce saying it is not well dried. Such experiences have resulted in huge losses for me.

For farmers, it is a worrying situation since neither can they consume the affected grains nor can they use them as seeds during the next planting season.

The introduction of Dry cards to smallholder farmers through the Nalmaco and Adefunke Desh-2SCALE and Ladipo & Lawani-2SCALE partnerships has helped farmers like Mr Abbas to measure the moisture level of his dried sorghum produce.

Dry Cards: a viable solution for grain producers

To solve the challenge of post-harvest losses caused by mould and fungus infestation, 2SCALE has introduced a technology called Dry Card to sorghum and groundnuts farmers in Nigeria. It is a technology used to determine if food is sufficiently dried to prevent the growth of mould during storage. Moulds will not grow if the air around a product is lower than 65% relative humidity. This technology comes in handy in the management of moisture content in grains. A single unit costs ₦410 ($0.99) in Nigeria.

The Dry Card consists of a laminated, business card-sized humidity card that contains cobalt chloride. When placed on a sample of dried produce, the card changes colour from pink to blue based on a humidity index. Blue indicates 35% humidity; a condition that makes it unlikely for mould to grow and produce aflatoxin. Pink indicates the 65% humidity threshold, which means that there is a risk of mould contamination.

Using the dry card is relatively easy. The card, and a sample of the dried grain are placed in an airtight container, such as a sealed plastic bag or a jar. After a brief wait, the card indicator will display a colour representing the measure of humidity. If cared for properly, the Dry Card can be reused several times.

Mr Abbas says that it is very efficient and easy to use. He recounts,

The card is not difficult to use, I just look at the readings and if it is above 65% the strip turns pink. This tells me the moisture content is high and it is unsafe to store at this stage. I then dry the produce further till the readings are 35%. Since I started using the dry cards two years ago, my produce has never been rejected by buyers. I am very happy that 2SCALE introduced such a technology and it is easily accessible even for us in the rural parts of Nigeria.

The experience of a groundnut farmer

Mr. John Saba is a groundnut farmer with 10 hectares of farmland in Tsaragi, Kwara State, Nigeria. He is one of the farmers in the Ladipo & Lawani-2SCALE partnership. Groundnuts, like any other grain, require proper post-harvest handling to ensure that they are safe before reaching the consumer markets. John’s biggest hurdle is appropriately drying his groundnut produce, in readiness for the market as he narrates,

Each season, I harvest up to 150 bags of groundnut (unshelled) per year. After harvesting comes the tedious process of drying the nuts. It entails spreading the nuts under the sun and storing them after a few days. However, this does not guarantee well-dried produce. It is at times disappointing since I still make losses as some of the produce gets mouldy and we have to dispose of them.

He describes his experience using the dry card as efficient.

I came to know about the dry card in 2021 when it was introduced to us by 2SCALE. It has been very effective and accessible to us at the cooperative level, and it is not difficult to use. I am now confident about the quality and safety standards of the produce I have in my store. This has helped me to retain my existing customers and get recommendations for more.

He says.

So far, 48,719 smallholder sorghum farmers and 5,015 smallholder groundnut producers have access to the Dry Card technology in Nigeria.

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