By Mary Mutisya
Beans are an important source of protein to many. Its consumption however remains limited because of its long cooking time, high fuel and water requirements. Although canned and frozen beans are available, they are often out of reach for most households due to their high cost and the need for refrigeration. For this reason, there has been a need to develop an affordable, convenient, on-the-shelf bean products that require less time, fuel and water to cook while at the same time maintaining the quality of the product. Pre-cooked beans are a solution to this and the good news is that through the collaboration of different research organizations such as KALRO, and CIAT, 12 bean varieties have been selected and identified as the best depending on colour, micro-nutrient content and agronomic traits for production and processing. Of the twelve varieties, the most common four are (NABE 4, NABE 14, Rose coco and Wairimu). These are now widely grown by farmers in Kenya and Uganda and are readily available for entrepreneurs willing to venture into business.
Steps of pre-cooking and packaging beans
The main steps involved in pre-cooking and packaging of beans are;
Sorting/cleaning
Sorting of the beans is done by hand picking any foreign material and separating them from the beans. These include stones, twigs, leaves e.t.c. For large scale producers, cleaning machines that use sets of sieves and air to remove foreign materials and other vegetable species are employed.
Soaking/Hydration
After the beans have been sorted, they are then soaked in water for about 30 minutes to help them cook faster and more evenly. Adding salt to the soaking water helps the beans cook faster by breaking the hard seed coating.
Blanching
This involves slight cooking of the already soaked beans to further soften them. The beans are immersed in hot boiling water for a maximum of five minutes. This helps deactivate enzymes and remove gases from the surface and intercellular spaces, thus preventing oxidation and discoloring of the product on the shelf. It also has the added benefit of reducing the amount of pathogenic and harmful microorganisms in the beans as well. This stage also helps to pre-warm the product.
Cooking
The cooking of pre-cooked beans involves heating the beans at high temperatures for a short period of time. This helps the beans to get cooked perfectly while retaining their sensory and physical appeal. The pre-cooked beans are then dried before packaging.
Packaging
If the beans are needed whole, they are then taken for packaging. This stage is crucial and the right packaging materials should be used. Clean glass jars or zip lock bags are recommended.
In cases where bean flour is needed, the cooked beans are first ground into a paste, dried and then ground into flour which is again dried. Several products can be made from this and these include ready-to-eat bean snacks, baked products and pasta as well as easy-to-cook bean products. In cases where instant flours are needed, the pre-cooked bean paste can be extruded to produce an instant flour and easy to cook bean product. Raw bean flours are rarely used industrially as the bean flour can develop off-flavors during storage.
Mary Mutisya is a nutritionist at Icipe.
mariahmutisya@gmail.com