Enhancing Nutritional Benefits and Reducing Mycotoxin Contamination of Maize through Nixtamalization

Naggayi Maureen, Archileo N. Kaaya, Joy Kauffman, Clare Narrod and Abel Atukwase

Background and Objective: Maize is majorly consumed in Uganda but has the low nutrient quality and high mycotoxin contamination. This study established the effect of nixtamalization on mycotoxin content, nutritional composition, physicochemical and sensory properties of Ugandan maize. Materials and Methods: The samples were nixtamalized before milling by soaking maize grains in a solution of; (a) 1% slaked lime ((Ca(OH)₂) and (b) 1% traditional liquid ash. The maize grains from each solution were washed in clean water and dried at 60°C to constant weight and milled into flour. The milled samples were analyzed for aflatoxins, fumonisins, nutrient content and digestibility. The pasting properties and sensory acceptability of the nixtamalized maize flour products (posho and porridge) were also studied. Results: Nixtamalization significantly (p<0.05) reduced aflatoxin (up to 90%) and fumonisins (up to 80%) but increased the ash and niacin content. However, the process slightly reduced fat, sugars, protein and dietary fiber. The flour prepared from lime-nixtamalized maize had the lowest peak viscosity (711cP), followed by ash-nixtamalized flour (1377cP), while the flour from non-nixtamalized maize had the highest peak viscosity of 1465cP. Overall, there was no significant difference among the sensory properties for porridge and posho prepared from nixtamal and non-nixtamal maize flour. Conclusion: The study findings suggest that nixtamalization is a promising and affordable processing technology for reducing mycotoxin levels in maize and enhances the nutrient profile of the maize products without compromising consumer acceptability in Uganda.

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