Stability of micronutrients in nutrigems during cooking and accelerated storage

摘要

Micronutrient undernutrition is one of the most common and preventable nutritional problems in the world. Several strategies have been developed to prevent and control micronutrient deficiency; however, the problem still persists. We have developed Nutrigems, a food-based micronutrient delivery vehicle which represents a simple technology to provide critical micronutrients to children using the food service logistics of an on-going school lunch program in developing countries. This thesis work was aimed at establishing the stability of micronutrients in Nutrigems after cooking and accelerated storage. Nutrigems made with corn flour and all purpose wheat flour were evaluated as a potential vehicle to deliver vitamin A (VA, as retinol palmitate), iron and the combination. Two types of iron sources were evaluated: sodium iron (III) ethylenediaminetetraacetate (FEDTA) and ferrous sulfate (FS). Nutrigems and rice were mixed (1:100 w/w) and cooked in a conventional rice cooker. Samples were stored at two relative humidities (RH) 33% and 77% within two temperatures 23 ??C and 40 ??C. Color, VA content and malondialdehyde-thiobarbituric acid (MDA-TBA) were measured at 0, 7 and 14 days after storage. VA was quantified using reverse phase HPLC with Photodiode Array (PDA) detection. Iron and MDA-TBA were quantified using spectrophotometric methods. After cooking, percent retention respectively were 92, 99 and 68% for VA, NaFeEDTA and the combination. Vitamin A stability after storage was more affected by temperature than RH. However, this changed in the presence of iron. The source of iron had the greatest effect on vitamin A stability, the level of oxidative rancidity and the final color of Nutrigems. Iron EDTA was chosen as it was the least reactive iron source. The optimal conditions for storage with iron EDTA were low RH conditions, which allowed respective retentions of VA of 87.7% and 84.37% for Nutrigems formulations containing only VA and the combination of VA with iron EDTA. These studies describe a promising technological alternative for its use in point of consumption, local fortification food programs for delivering critical micronutrients and improving nutritional quality of the meals provided in the School Lunch Program in Honduras or other programs with similar logistics.