Effect of Storage Condition on Retention of Vitamins in Selected Commercial Fortified Maize Flour in Kenya

Food fortification is one strategy that has been used to overcome micronutrient deficiencies among vulnerable populations. Maize, a common staple food in Kenya, has been used as a suitable fortification vehicle. However, several factors, including storage conditions, impact micronutrient stability in fortified maize flour.This study aimed to to assess the influence of storage condition on the retention of retinol and B-vitamins in selected commercial fortified maize flour. Fresh samples of fortified maize flours from two brands (coded XX1 and XY2) were sampled from the manufacturers at the point of production. The storage stability of retinol and B-vitamins in the two brands (XX1 and XY2) was monitored for 6 months at 25 °C/ 75 % relative humidity and 35 °C/ 83 % relative humidity. Retinol and thiamine were the least stable vitamins in both flour brands, while riboflavin and folate were relatively stable. Niacin was the most stable vitamin. Retinol was the least stable vitamin for brand XXI at both 25 °C/75% RH and 35 °C/83% RH, followed by thiamine, riboflavin, folate, and niacin. However, brand XY2 showed that under both storage conditions, thiamine was the least stable vitamin, followed by retinol, riboflavin, folate, and niacin. Vitamin retention was higher in samples stored at a lower temperature and relative humidity (25 °C/ 75 % RH) than in samples stored at higher temperature and relative humidity (35 °C/ 83 % RH) for both brands. In conclusion, thiamine and retinol were generally more susceptible to storage losses. Although the vitamin content in the flour samples decreased during storage, the changes in both storage conditions (except for riboflavin) and both brands were not significantly different.