Resumen de Strategies to improve the oxidative stability of bakery products fortified with heme iron
Mercedes Alemán Ezcaray
Iron deficiency is the most prevalent nutritional issue worldwide. The fortification of food products could help covering the iron requirements, mainly in certain population groups where prevalence of iron deficiency anaemia is high because its amount in the diet is poor and/or presents low bioavailability. In this regard it is worth to mention that the population groups with higher prevalence of iron deficiency are both women at childbearing age and children. However, iron fortification should take into account several variables that determine its effectiveness being the bioavailability of the iron form used and its interaction with the matrix the most crucial ones. The aim of this thesis is to obtain a fortified food product with a high bioavailable iron while being accepted by consumers and stable towards oxidation. In this regard, a sandwich-type cookie filled with a chocolate cream has been selected as example of heme iron fortification in bakery products. The presence of chocolate, apart from making the food product to be more appealing to children, may help disguise the intense colour of the heme iron ingredient, which is intended to be used for its high bioavailability. Since palm oil is widely used in the manufacture of biscuits, cakes and pastries, it is planned to previously study those strategies that minimize oxidation in a model based on palm oil fortified with heme iron before these are employed in the final food products. By means of this model, we assessed the efficacy of the following strategies: the addition of antioxidants; the heme iron ingredient encapsulation and the combination of both strategies. The strategies that were shown to be efficient in this fortified palm oil model were further assessed on sandwich-type chocolate cookies fortified with heme iron. In these cookies and over a period of one year of storage in the dark at room temperature, the oxidative stability and consumers’ overall acceptability has been studied By combining the two strategies, the addition of an antioxidant (ascorbyl palmitate) and the encapsulation of heme iron by co-spray-drying it with calcium caseinate, the cookies were oxidative stable and accepted by consumers over one year of storage at room temperature in the dark.
