CONICET | Buscador de Institutos y Recursos Humanos

Many chronic non-communicable diseases are related to malnutrition and diet has a great impact in the maintenance of good health. The design of healthier foods could be a strategy to improve human nutrition, working in broadly consumed foods for each target population. The choice of cookies in order to introduce nutritional factors in diet in the present work was founded in the fact that they are widely consumed, well taste, and easy to carry as snacks. The objective of the present work was to produce healthier cookies complemented in their protein quality and supplemented with antioxidants derived from blueberries leaves. First, the relation wheat/soy flour was calculated to achieve protein complementation focusing in lysine content (the limiting amino acid of wheat flour) when compared with the FAO model protein. Four levels of blueberries leaf powder (BBLP) were used as a source of antioxidants: 0, 2.5, 5 and 7.5% (p/p). Sugar, trans fatty acids free margarine, and water were included in the recipe. The cookies dough was obtained using a typical kitchen robot, left in the refrigerator for 40 min (in order to reach optimal lamination consistency), and rolled using a dough roller. Cookies were cut with a circular shape cutter of 5 cm diameter and cooked in a convective electric oven at 180 °C for 8 min, maintaining a moist ambient during the process. After baking, cookies were cooled at room temperature. Then, some of them were used for hardness evaluation (through the three bending point test), surface and internal color determination (using digital image analysis to obtain L*, a* and b* parameter and to calculate browning index), and cookie quality analysis (by measuring cookies diameter and thickness, and calculating spread factor). Subsequently, other cookies were milled and used for moisture content and antioxidant activity determination. Slight differences were observed in hardness with an increasing tendency when BBLP concentration changed from 2.5 to 7.5%. Moisture did not show any change with BBLP content. Analyzing surface color parameters lightness (parameter L*) was the most influenced by BBLP, resulting in darker cookies, in agreement with the increase in the browning index. The other color parameters showed slight changes with higher a* values (redder) and lower b* value (bluer). When color of the cross section was analyzed, only L* was affected by the addition of BBLP. Increasing levels of BBLP produced an increase in the antioxidant activity of the cookies. The improved antioxidant properties of cookies might be due to the incorporation of phenolic compounds, mainly various catechins, which had been shown to possess antioxidant activity. Sensory studies are being carried out to evaluate acceptability by consumers.