More iron, zinc: New beans have an edge

Earlier this year, National Agricultural Research Organisation (Naro) released bean varieties, which have higher levels of iron and zinc for production by Ugandan farmers.

Dr Stanley Nkalubo, head of legumes research at NaCRRI—one of Naro’s research institutes, says use of bio-fortified foods is an inexpensive method to overcome or prevent malnutrition issues especially for resource-poor families.

The new varieties have an edge in terms of higher levels of iron and zinc. “These varieties have a 20-25 per cent increase in iron, mature earlier and may require less rain.

Thus, they can be grown in areas with low rainfall,” he adds. “They mature in 60-75 days for the bush varieties (NAROBEAN 1, NAROBEAN 2 and NAROBEAN 3) and 85-95 days for the climbers (NAROBEAN 4C and NAROBEAN 5C.”

Distinguishing factors between new and old varieties vary with each type. With their unique features, they are given serial names. NAROBEAN 1 (Kidney shaped, greyish with black stripes), NAROBEAN 2 (Oval shaped with red and white speckles), NAROBEAN 3 (medium-sided oval shaped and yellow), NAROBEAN 4C (white and red speckled and roundish) and NAROBEAN 5C (Yellow kidney bean). The letter C means it is a climber and requires stakes for support. The first three aforementioned are bush beans.

Dr Nkalubo points that because of higher nutritional value, they are therefore very important for women, especially those of child-bearing age, and young children.

Crop care

Dr Stanley Nkalubo, NaCRRI’s head of legumes research, notes that the agronomic practices are still the same for both the newly released varieties and the other beans. “Spacing should be at 50 cm between rows and 10 cm within row for the bush beans (NAROBEAN 1, NAROBEAN 2 and NAROBEAN 3) and 50 cm between rows and 20 cm within row for the climbers (NAROBEAN 4C and NAROBEAN 5C).”

It is recommended for farmers to apply either artificial or organic fertilisers in areas where the soils are poor or not as fertile.

On whether, there is differences in prices, Dr Nkalubo clarified that there would be none, explaining that the cost will remain at the same level with both.

Also, studies that have been conducted to evaluate iron and zinc retention after cooking. This is either by regular pot or pressure cooking, with and without previous water soaking, and broth. It was established that regardless of the cooking method, with or without previous water soaking, the highest zinc concentration was found in the cooked bean grains.

However, pressure cooking and previous water soaking diminished iron retention in the cooked grains, while increasing it in the broth. This confirmed that the common bean was an excellent source of iron and zinc for human consumption, and it was suggested that beans should be consumed in a combined form, that is grain with bean broth.