Retention of phenolic compounds and antioxidant properties in potato bread obtained from a dough enriched with a powder from the purple cv Vitelotte

To satisfy the increasing demand for products with higher nutritional value, bread was fortified with purple potatoes. Potato bread is a variation of traditional bread, but the ancient cv. Vitelotte, with purple pulp, has not been taken into consideration yet. Changes in nutraceutical properties were estimated analyzing anthocyanin contents, phenolic composition as well as antioxidant power. Purple potatoes contained anthocyanins, showed higher values of free and conjugated phenolic acids and a higher antioxidant activity compared to a commercial yellow potato. In purple bread total amounts of free and conjugated phenolic acids were slightly affected by baking and showed values two-, three-fold higher than in yellow potato. Bread also retained high levels of chlorogenic acid and contained conjugated myricetin. Phenolic composition of purple bread explains its higher antioxidant activity compared to the yellow potato, and suggests that Vitelotte can represent a good alternative in the fortification of bread.