Retention of Vitamins A and D in Fortified Soybean Oil During Ethiopian Traditional Cooking and Shelf-Life Stability During Storage.

Vitamin A and vitamin D deficiencies continue to pose serious health challenges, especially in low- and middle-income countries like Ethiopia. One promising way to tackle this issue is by fortifying everyday foods-such as cooking oils-with essential nutrients to help improve the overall intake across communities. This study investigated the stbility of vitamins A and D in fortified soybean oil during common Ethiopian cooking practices and over time during storage. To test the vitamins' shelf life, the fortified oil was stored for 6 months at two temperatures: room temperature (25°C) and a warmer 37°C. As expected, both vitamins became less stable; the longer they were stored, and the higher the temperature, the greater the loss. Notably, vitamin D broke down much more than vitamin A under the same conditions. After 6 months, vitamin A levels dropped by just over 5% at room temperature and nearly 9% at 37°C. Meanwhile, vitamin D levels fell sharply by 59% and 62% at room temperature and 37°C, respectively. The study also examined how cooking affected vitamin levels. Food was prepared using the fortified oil at 250°C for 80 min. Even under these high-heat conditions, more than 60% of vitamin A and a remarkable 97% of vitamin D were retained. These results show that vitamin A is more sensitive to heat, while vitamin D is more vulnerable to long-term storage.