Apple pomace has been proposed as a quality enhancer for gluten-free bread, but its composition and physicochemical features differ significantly depending on the apple cultivar. The objective of this article was to characterize apple pomace powder (APP) from certain varieties from the Basque Country and to study the feasibility of adding it to gluten-free bread, focusing on physicochemical and nutritional aspects. APP was obtained by washing, drying and grinding, and it was added at 0, 5, 6 and 8%, together with other ingredients, such as gluten-free flours, corn starch and whey protein. APP had a reddish-grey coloration (L* 56.49 ± 1.39, a* 11.07 ± 0.47, b* 27.69 ± 1.76), pH 4.19 ± 0.15 and Aw 0.235 ± 0.084. Pomace powder was used successfully in higher amounts than experiences reported before. Key physicochemical parameters such as specific volume (≥2.5 cm³/g) and cohesiveness or resilience values (0.538 and 0.378, respectively) suggested good acceptability for gluten-free breads with 8% APP. Additionally, breads were a source of antioxidant potential (437.66 ± 38.95 µM DPPHeq/g APP), fiber (80.13 ± 6.07 g/100 g) and micronutrients such as Cu, Mg, Mn and Fe. In conclusion, local apple varieties are a good source of raw material for gluten-free bread manufacture, which offers a solution for environmental pollution and may contribute to boosting the circular economy.

The gluten-free (GF) food market has been growing exponentially in recent years. However, GF products could contribute to imbalanced diets. The main objective of the present work was to perform a temporal nutritional comparison of GF foods over the last nine years. At the same time, the nutritional compositions of 104 GF products currently marketed in Spain were assessed and compared with their gluten-containing counterparts. Diets including GF products and the equivalent diets with homologous products with gluten were compared as well, the subjects being 25 adult celiac patients. A comparison of GF products (GFPs) in 2013 and 2022 showed nutritional differences in the groups of cookies, breakfast cereals, doughs/puff pastries/pizzas, and breads. The pasta group stands out from the rest due to an important decrease in energy, protein, simple carbohydrates, saturated lipids, dietary fiber, and salt. Comparing GF and gluten-containing homologous products in 2022, the major differences were found in protein and salt. Accordingly, GFPs lead to a diet lower in protein and higher in carbohydrates. Despite improvements in the formulation of GF products in recent years, their macronutrient profile maintains marked variation, and they cannot be considered nutritionally equivalent to their gluten-containing counterparts.