Celiac disease (CD) is a chronic autoimmune disorder affecting about 1% of the
population, characterized by adverse immune responses to gluten. The only effective therapy is a permanent gluten-free diet that shows numerous nutritional deficiencies. For all the above, the objective of developing a functional sourdough gluten-free bread formulation enriched with the by-product of the agro-food industry of Opuntia ficus-indica or purple prickly pear (HCM) is presented. For this, four formulations were developed in order to evaluate their effects: Control; P1, bread with dried HCM skin flour (H1); P2, bread with dried HCM skin encapsulated flour (H2); P3, bread with dried HCM skin flour pre-treated with PEF (H3); and, a Commercial formulation. In this way, a nutritional characterization was carried out by determining moisture, proteins, fat, ash, carbohydrates, energy value and fiber; the pH, total titratable acidity (ATT), color and mineral composition of the breads and by-products of HCM were analyzed; the
microstructure (SEM) and starch, lactic acid and acetic content of the breads were evaluated; water and oil retention capacities (WHC and OHC) and solubility of the ingredients in the formulations were determined; and, the antioxidant capacity (FRAP, DPPH, ABTS) and total phenolic content (TFC) (Folin-Ciocalteau method) of the formulations, skin flours of HCM and other selected ingredients were evaluated.
The most outstanding results were, in terms of nutritional properties, an increase of
10,48% of ash, 10,32% of FDI, 352,63% of FDS y 35,96% of FDT, as well as a decrease of 6,19% of moisture, 2,54% of carbohydrates and 7,77% of energy value when adding HCM skin flour treated with PEF prior to drying (H3). Significant increases in the content of Ca2+ and K+ were also highlighted due to the addition of H3 to the bread formulation, as well as the notable improvement in antioxidant capacity and TPC in P2 bread with encapsulated dried HCM skin flour. In conclusion, the incorporation of this by-product and the treatments to which it was subjected allowed the nutritional improvement of gluten-free breads, especially in terms of antioxidant capacity, TPC and mineral content.