THE POTENTIAL FOR NJAHI (Lablab purpureus L.) IN IMPROVING CONSUMPTION ADEQUACY FOR PROTEIN, IRON AND ZINC IN HOUSEHOLDS: A CASE FOR NANDI SOUTH DISTRICT, KENYA

ABSTRACT
Almost 850 million people in the developing world go without food every day, with one third being Africans living below the poverty line. Up to 12.5 million of these people are Kenyans. This has led to their development of major macro and micro nutrient deficiencies. The deficiencies have stemmed from multifaceted problems namely; low utilization and inadequate intake due to inadequate information on alternative potential food sources and their appropriate utilization. Food based strategies to mitigate these malnutrition problems have been tried by many with varying degrees of success.
The case for lablab, being a multipurpose crop was introduced to solve these challenges in three dimensions namely: Improve soil fertility, Increase yield for cash and as source of food. This study examined its food utilization potential in Nandi South district.
The work was part of a larger intervention project entitled To Reinvigorate Smallholder Mixed Farming Systems in Western Kenya, using lablab under Dry Grain Pulses Collaborative Research Project (DGP-CRSP), in four soil fertility gradient zones in Nandi South.
The study design in Nandi South district was analytical to explore; socio demographic and economic factors as influence protein, iron and zinc intake. Profile the protein content, iron, zinc and anti-nutritive factors and effect of preparations on them. A total of 132 households involving 65 lablab and 67 non-lablab growing households with a total of 800 people were purposively selected for study. Baseline data on demography, socioeconomic characteristics and consumption pattern for protein, zinc and iron foods
2
were collected using pretested questionnaire. Other determinations were nutritive stress factors associated with these foods, protein adequacy, zinc and iron intake.
Proximate composition, zinc and iron were determined for both lablab grains and leaves while cookability and anti-nutrients were analyzed in grains. Further tests done were determination of effect of soaking and cooking periods on zinc, iron and anti-nutrient contents in grains.
The households studied had a mean household size of 6 with a sex distribution of 51% females and 49 % males and a dependency ratio of 87%. The established income of the study population majorly from farming (70%) showed that 85% of them were earning half below the recommended 1 US dollar per person per day.
Using a pretested 24hr recall and a seven day food frequency questionnaire, it was established that the frequency of consumption of protein, zinc and iron rich foods by most of the households was low (less than 3 days in a week). Only cereals and their products had adequately been consumed by more than 80% households within the previous seven days. From the survey, 22%, 13% and 47% of the study population did not meet the recommended requirements for protein, zinc and iron respectively.
Analyses were carried out to establish nutrients and anti-nutrients composition for both lablab grains and leaves. The grain had a mean protein content of 22%, zinc of 34mg/kg and iron of 57mg/kg while on leaves the crude protein was 25%, zinc of 30mg/kg and iron of 28mg/kg.
The effect of soaking and cooking on lablab grain nutrient and anti-nutrient content were determined, In vitro protein digestibility increased significantly with soaking time by about 11% and 15% at 12 and 24 hours of soaking respectively also reducing tannins significantly by about 74% and 76% respectively and to undetectable levels for trypsin inhibitor. Soaking the grains for 10, 12 and 24 hours reduced the cooking time by 67%, 70% and 74% respectively. It can be concluded that like any other food legume, Lablab is a good source of dietary protein, zinc and iron but holds a better promise given its multipurpose function.