TITLE:
Proximate and Mineral Composition of Selected Sweet Potato (Ipomoea batatas L.) Genotypes Grown in Lesotho
AUTHORS:
Puleng Letuma, Thabang Mkhehlane, Marealeboha Mofube, Ntsoaki Moeketsi, Monica Lephole
KEYWORDS:
Berea, Agro-Ecological Zones, Composition, Maturity, Crude Fiber
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.17 No.6,
June
30,
2026
ABSTRACT: Malnutrition and micronutrient deficiencies remain significant public health challenges in Lesotho, largely driven by dietary diversity and the underutilization of nutritionally valuable indigenous crops. Sweet potatoes play a vital role in strengthening food security and promoting better nutrition in vulnerable areas. This study evaluated the proximate and mineral composition of four sweet potato genotypes (Khumo, Monate, Ndou, and W119) collected from South Africa and cultivated in the Berea District of Lesotho. A field experiment was arranged in a randomized complete block design, with three replications. At maturity, the root samples were harvested, cleaned, crushed, pooled, and analyzed at the Crop Science Laboratory of the National University of Lesotho. AOAC methods were used to analyze the proximate composition, while ultraviolet-visible (UV-Vis) and atomic absorption spectroscopy (AAS) were used to analyze mineral content. The following proximate compositions were determined, including carbohydrates, crude protein, crude fiber, crude fat, ash, total soluble solids (TTS), and moisture content. Mineral elements analysed included potassium, phosphorus, calcium, magnesium, sodium, zinc, iron, manganese, and copper. The proximate composition varied across genotypes, with values ranging from 0.12% - 0.80% (crude protein), 0.16% - 0.46% (crude fat), 0.83% - 1.43% (crude fibre), 64.94% - 70.62% (moisture content), 28.13% - 32.71% (carbohydrates), 0.87% - 1.27% (ash), and 2.00% - 6.00% (TTS). Mineral concentrations ranged from 0.70% - 1.05% (potassium), 0.52% - 0.94% (calcium), 2.52% - 5.89% (sodium), 0.22% - 0.43% (magnesium), 0.40% - 0.76% (phosphorus), 0.16% - 1.40% (copper), 0.27% - 0.63% (zinc), 0.54% - 1.10% (manganese), and 0.19% - 0.30% (iron). Findings from this preliminary investigation reveal that the Khumo and W119 sweet potato genotypes possess notable nutritional value with promising potential for incorporation into sustainable dietary strategies in Lesotho. However, further research is required for comprehensive elucidation of their efficacy and adaptability across diverse agro-ecological zones.