Dry Cards

Summary

The DryCard is a simple, low-cost tool that measures food dryness. This technology enables users to determine whether their product is dry enough to prevent mould growth and mycotoxin production. The product enables smallholder farmers and traders to measure the relative humidity of dried food before storage using a cobalt chloride humidity indicator strip.

Challenge

Drying is a technique used to preserve harvested products, but knowing when products are dry enough can be difficult. When products are not properly dried they can grow mould and produce harmful mycotoxins such as aflatoxins. Common methods to test for dryness such as biting, touching, or sniffing the product are unreliable and inaccurate. Electronic devices that measure moisture or humidity are often too expensive and difficult to use.

Contamination of dry foods by mould is a major global problem that contributes to both food security challenges and disease transmission. It is estimated that mould affects approximately 25 per cent of the world’s crops, with aflatoxins, a type of toxin produced by mould, being responsible for health problems such as acute poisoning, liver cancer and stunting.

Aflatoxins are a particular problem in Africa, where commodities are stored under hot, humid conditions. Contamination of staple crops such as maize and sorghum directly reduces the availability of food.  Producers may earn less because of product rejection, reduced market value or lack of access to formal markets and higher-value international trade. Lower farmer incomes means less ability to purchase food for the family, which translates to higher levels of hunger and poverty. 

It is estimated that the continent loses between EUR 400 and EUR 600 million a year in export earnings, and that about 26,000 Africans living south of the Sahara die of liver cancer every year through chronic aflatoxin exposure. 

If left unaddressed, the problem of mould contamination will continue to present a formidable obstacle to achieve the first three Sustainable Development Goals of no poverty, zero hunger and good health and wellbeing.

Solution

Post-harvest toxin production can be prevented by ensuring that products are sufficiently dried before storage. A major challenge, especially for smallholder farmers, is the lack of access to testing and certification facilities. Although there are electronic moisture meters that can measure humidity, available instruments can be too expensive for smallholder farmers, and most of these tools require regular calibration.

Retailing at below US$1, the DryCard is an inexpensive device developed by University of California, Davis for determining if dried food is dry enough to prevent mould growth during storage. The tool is intended for smallholder farmers who cannot afford the expensive moisture meters in the market.

To use the DryCard, a farmer simply places the DryCard and a sample of the dried product in an airtight container such as a sealed plastic bag or jar. After a few minutes, the card’s indicator, a strip of cobalt chloride, will change color based on the equilibrium relative humidity. The farmer then matches the color of the strip with the corresponding scale on the card. A pink color on the strip means the product is too wet for safe storage, while blue or mauve means it is adequately dried.

Training entrepreneurs can easily scale the DryCard to manufacture and distribute locally. The DryCard can be used for up to two years. Due to its low cost, it is also easily replaceable if an older DryCard no longer works well.

Results

Small-scale entrepreneurs in a number of countries are producing and marketing DryCards; some 60,000 cards have been distributed so far. After approximately one year of operating this scaling strategy, the Horticulture Innovation Lab had partnered with nine businesses selling the DryCard in ten countries.

The first DryCard franchise was launched in the second half of 2017 by an entrepreneur in Tanzania. In five months, the entrepreneur and her team sold 2,500 DryCards to 500 local farmers and several organizations such as the International Rescue Committee and the United Nations Food and Agriculture Organization (FAO).

Currently, there are twelve entrepreneurs based in thirteen countries, and several have the capacity to manufacture and ship cards within continents. In Africa, there are six entrepreneurs (Ghana, Kenya, Nigeria, Rwanda, Tanzania, and Uganda). In North America there are two (one operating in both Mexico and Guatemala and another in Haiti). In Asia there are four (India, Myanmar, Nepal, and Thailand).

 Lessons Learned/Potential for replication

The DryCard should be used as part of a Dry Chain approach for dried products, with hermetic-type storage bags, and efficient dryers (chimney dryer, pallet dryer) to ensure products are dried properly and stay dry during storage. Adoption of the DryCard is improved if the DryCard is introduced to potential customers in the form of a postharvest training program. The DryCard, alongside postharvest training can be targeted to following segments:

- Producers can integrate DryCard into their business to ensure that their product is not rejected by buyers for high moisture content or potential contaminated product.

- Cooperatives can adopt DryCard to integrate a low-cost tool to improve their drying processes and meet buyers purchase specifications.

- Aggregators may offer the DryCard solution as part of a bundled input loan to producers to achieve quality assurance standards.

Next Steps

The Horticulture Innovation Lab encourages local businesses to pursue the production and distribution of the DryCard with the goal of achieving sustainability, creating jobs, and independence. Local businesses or individuals can submit a business plan to the Horticulture Innovation Lab for review and potential inclusion into the DryCard distribution network.

Apply Here

Where to buy the DryCard

- Ghana: Ofori Agrochemical Services

- Guatemala and Mexico: Earth Empower

- Haiti: Fondation Haïtienne de Développement Agricole Durable

- India: Vivia Foundation

- Kenya: BetterCrops Ltd.  

- Myanmar: Kasante Enterprise

- Nepal: R&D Innovative Solutions

- Nigeria: Willow Foundation 

- Rwanda: Development Solutions Consulting Ltd. 

- Tanzania: Market Infrastructure, Value Addition and Rural Financial Services (MIVARF)

- Thailand: Go Organics

- Uganda: Mwino Group