Manufacture of gluten-free products requires the use of preselected raw materials. The number of such ingredients is limited; therefore, the portfolio of gluten-free bread is less variable and attractive in terms of their appearance, taste and nutritional value in comparison with traditional bread. The aim of the study was to apply debittered acorn flour as a natural nutritional enrichment of gluten-free bakery products and to check its effects on rheological properties of the dough and quality and staling of the bread. The analysis of rheological properties of gluten-free dough supplemented with acorn flour exhibited significant increase in the moduli G′ and G″ and a decrease in phase shift tangent, which denotes firming of dough structure. Introduction of limited amounts of acorn flour caused an increase in bread volume and improved crumb characteristics. In consequence of a diminished starch retrogradation, the respective loaves exhibited slower staling. Bread supplemented with acorn flour exhibited improved sensory acceptance. The obtained results signify that the application of debittered acorn flour in gluten-free baking could be useful for nutritional reasons, as it enriches bread with protein, minerals and dietary fiber, but also because of its technological effects, including structure strengthening, and sensory improvement.

The aim of the work was to evaluate the influence of prebiotic additives on gluten-free breads, and to assess the effectiveness of gluten-free bread supplementation with the selected prebiotics: inulin, oligosaccharide syrup and bitter-free chicory flour. The breads with the 3, 5 or 8% additions of the mentioned prebiotics were baked and stored for 48h. During this period the following analyses were performed: a texture profile, the content of mono-and oligosaccharides, and of inulin. The best effects on sensory features of gluten-free bread were observed when applied medium doses of prebiotics, being a 5% inulin supplemented bread the highest sensory scored. The addition of 5 and 8% of inulin, FOS syrup and chicory flour at all applied doses reduced the crumb hardening rate during the 3 days storage period. Content of fructooligosaccharides with DP 3–5 in standard bread was 0.1%, and in the supplemented breads did not exceed 0.3%. Addition of Frutafit preparation and bitter-free chicory flour enriched bread with inulin up to 1–3.5g/100g, the highest preservation level was observed in the case of chicory flour addition.

Gluten-free products based on starch and hydrocolloids are deficient in nutrients and do not contain pro-health substances. Therefore, they should be enriched in raw materials naturally rich in antioxidants, especially if they are intended for celiac patients, prone to high oxidative stress. Apart from the traditionally used pseudo-cereals, seeds, vegetables and fruits, innovative substrates such as the by-product (especially in Poland) dry apple pomace could be applied. The study material consisted of gluten-free bread enriched with apple pomace. The content of individual polyphenols, the content of total polyphenol and flavonoids, and also the antioxidant potential of the bread were determined by the UPLC-PDA-MS/MS methods. It was observed that apple pomace was a natural concentrate of bioactive substances from the group of polyphenols. In summary, gluten-free bread with 5% content of apple pomace showed the highest organoleptic scores and contained high levels of phenolic compounds. The values of total phenolic content, and the amounts of flavonoids, phenolic acids and phloridzin in this bread were 2.5, 8, 4 and 21 times higher in comparison to control.