Nutritional, functional, and microbial qualities of legume-based flour blends processed by SMEs in Zambia and Malawi compared to standard Corn-Soy Blend Plus (CSB +): a cross-sectional study.

Abstract

Background: Legumes enhance food security in developing countries, necessitating an understanding of their properties. This study examined the nutritional, functional, and microbial qualities of legume-based flour blends from Small and Medium Enterprises (SMEs) in Malawi and Zambia. SMEs were chosen for their key role in local food production, distribution, and complementary food supply.

Method: A total of 36 legume-based flour blend samples were collected using snowball sampling, consisting of 21 samples (7 sets of 3 similar samples) from SMEs in Zambia and 15 samples (5 sets of 3 similar samples) from SMEs in Malawi. Samples were analyzed for proximate composition, energy, iron, and zinc content. The nutritional contributions to the Recommended Dietary Allowances (RDA) for children aged 1-3 years were assessed. Additionally, functional properties such as water-holding and oil-holding capacities were measured. Microbial analysis was performed, and the data were statistically analyzed to determine significance (p ≤ 0.05).

Results: Our findings revealed substantial variability in the nutritional content of these flour blends. Protein content ranged from 9.4% to 41.5%, carbohydrates from 8.1% to 71.3%, crude fat from 2.3% to 26.8%, and crude fiber from 6.2% to 35.2%. Iron and zinc levels also varied significantly, from 2.9 to 21.9 mg/100 g and 2.2 to 5.2 mg/100 g, respectively. These inconsistencies highlight a lack of standardization in nutrient content for blends intended for infant feeding. When prepared as 96 g porridge servings for children aged 1-3 years, the blends provided notable contributions to the Recommended Dietary Allowance (RDA). However, their nutrient levels were generally lower compared to the standard Corn-Soy Blend Plus (CSB +). The flour blends also showed variations in physico-functional properties, and some had microbial loads exceeding 250 cfu/g, reflecting inadequate hygiene practices during processing.

Conclusion: To enhance their products, SMEs should ensure that their flour blends meet both nutritional and safety standards while striving to match or surpass the nutrient content of CSB + to remain competitive in the market.