Laillou A, Hafez SA, Mahmoud AH, Mansour M, Rohner F, Fortin S, Berger J, Ibrahim NA, and Moench-Pfanner R.
September 2012, Food and Nutrition Bulletin
Fortification of vegetable oil with vitamin A is considered a cost-effective and simple to implement strategy, but the stability of vitamin A remains a limiting factor. To account for losses of vitamin A, oil producers add an overage. Optimizing the amount of this overage can result in considerable savings for industry and government while ensuring a supply of adequately fortified oil to consumers. To estimate vitamin A losses in oil with different chemical characteristics, samples of fortified oils with different chemical characteristics were collected from two Egyptian companies (oil A and B) and stored for 1 month. Vitamin A levels were analyzed periodically during storage to determine losses over time, and peroxide values were determined. Fortified oil B, with a high peroxide value (5.8 mEq/kg), exposed to sunlight had significantly higher losses of vitamin A after 4 weeks than fortified oil A, with a low peroxide value (0.4 mEq/kg): 31.1% vs. 19.7% (p < .001), respectively. In semi-dark conditions, the vitamin A losses after 4 weeks in fortified oil B and fortified oil A were significantly different: 26.1% and 0.7% (p < .001), respectively. In an accelerated storage test, the vitamin A loss in 8 days was 48.3% for fortified oil B and 4.2% for fortified oil A (p < .001). Based on these results, the study shows a significant effect of peroxide level (one indicator of the quality of oil) on the stability of vitamin A, regardless of storage conditions. To optimize and sustain vitamin A levels in fortified oil, governments and industries should minimize the peroxide level to less than 2 mEq/kg at production.