Potential of underutilized Dolichos lablab (lablab purpures) seeds in improving nutritional quality and livelihood in Tanzania

Abstract

Lablab is a climate-smart legume that is underutilized despite its potential for food, and income. Less research attention is linked to its underutilization limiting its contribution to achieving Sustainable Development Goals (SDG) 1, 2 and 3. This calls to search for synergies to the further improve Lablab utilization in Tanzania. Both qualitative and quantitative methods were employed. A total of 344 Lablab farmers and 40 traders were interviewed to collect information on knowledge, attitude, and practices (KAPs), Lablab value chain and dietary diversity from the selected districts in Morogoro, Manyara, Arusha and Kilimanjaro regions of Tanzania. A total of 30 accessions were collected from the local farmers and NM-AIST Genebank. The accession collected were evaluated for nutritional quality using standard methods. The best nutrient dense four accessions (D-394, ELD K2, HA-4 and D-96) were further used to formulate Lablab cookies. The study revealed that KAPs vary among farmers in Babati (39.6%) and Arumeru (27.3%). Arumeru had a positive attitude toward black accessions (80.2%) for marketing, whereas non black accessions were less well-known. Farmers were the primary actors, contributing for 70% of the natural assets for livelihood. Accession D-422 ranked higher in protein content by 28.3%. Sprouting significantly (p<0.001) reduced phytic acid in D-360 (64.6%), tannins in HA-4 (94.8%), and trypsin inhibitors (TIs). Fermentation significantly (p<0.001) decreases phytic acid by 75% in HA-4 and D-96, and tannin by 61% in HA-4 as well as trypsin TIs in ELD-K2, HA-4, and D-96 by over 90%. Furthermore, sprouted seeds had higher mineral concentrations in D-96 and HA-4, such as Mg (0.11-0.25%), (0.09-0.20%), and Zn (0.03-0.34%) and (0.23-0.32%), respectively, whereas fermented seeds increased Mg concentration in HA-4 from 0.09 to 0.23% and Zn content (0.23-0.35%). Lablab cookies made from HA-4 and D-96 fermented flours were highly preferred. HA-4 cookies scored the highest (> 8) similar to control. On the other hand, black Lablab's revenue contributed less to dietary diversity than nonfood commodities as per the Principal Component Analysis. Farmers' diets were over 90% cereal-based, with less Lablab-eating foods. The study concluded that wise income allocation is essential for both non-food items and nutritive food. Furthermore, the best accessions represent a diverse supply of high-quality food that, when fermented, greatly reduces anti-nutrients, yielding healthier and convenient nutritious foods. As a result, among the recommendations, value-addition and promotion of underutilized seeds could increase consumption and revenue, particularly for smallholder farmers in Tanzania.