در روغن هاي نباتي مايع و جامد غني شده A بررسي اثر نور و حرارت بر ميزان پايداري ويتامين

Background: Deficiency of micronutrients such as vitamin A is one of the nutritional problems in developing countries that could be successfully prevented by fortification of the food products. Since vitamin A is fat-soluble, we have chosen sunflower liquid oil and hydrogenated blend oils as the carriers for vitamin A for our study. Materials and methods: During this study, vitamin A-palmitate (200 IU/gr) was added to the samples and after packing, the hydrogenated and liquid oil samples were stored at the temperatures of 25 and 45 degrees centigrade for 6 months both in darkness and exposed to sun light. All fortified samples were used for cooking (rice) and frying (potato) to determine the effects of these processes on the stability of vitamin A. Results: After 6 months, the highest stability of vitamin A (95%) was observed in hydrogenated oils stored at 25 degrees centigrade, whereas the lowest stability (50%) was seen in liquid oil samples stored at 25 degrees centigrade and exposed to sun light. Cooking and frying processes caused vitamin A losses of 5 and 10%, respectively. Changes in peroxide values and stability of vitamin A were in the opposite direction, i.e, by increasing peroxide values in the fortified oil samples, vitamin A was decreased. Conclusion: Since sun light is the major cause of vitamin A loss in oil samples, we recommend fortification of the liquid and hydrogenated oils with vitamin A and improvement of the products package.