Quality- and Health-Promoting Compounds of Whole Wheat Bread with the Addition of Stale Bread, Cornmeal, and Apple Pomace.

The aim of this study was to evaluate the effect of extruded preparations on the bioactive and nutritional properties, vitamin B content, volatile compound profile, and quality of whole wheat bread. Extruded preparations based on stale bread (secondary raw materials) and apple pomace (byproducts) were used as bread additives. It was found that the preparations did not enrich the bread in protein but in health-promoting compounds, especially gallic acid, protocatechuic acid, caffeic acid, p-coumaric acid, rutin, quercetin, and B vitamins. Extruded preparations had a positive effect on the quality of the bread produced, such as yield and cohesiveness, and gave it a pleasant aroma. It was shown that among all the examined bread samples with added extruded preparations of stale bread, the cornmeal and apple pomace bread samples with 15% extruded preparation (containing 55% cornmeal, 30% stale bread, and 15% apple pomace) had sufficient nutritional value, the highest amounts of gallic acid, protocatechuic acid, p-coumaric acid, caffeic acid, rutin, and quercetin; medium amounts of ellagic acid; high antioxidant activity determined in vitro using four methods (by DPPH, ABTS, power (FRAP), and Fe(II) chelating assays); adequate quality; and significant amounts of vitamins, especially B1, B2, and B3. This type of extruded preparation should utilize apple pomace, which is a byproduct, and stale bread, which is a secondary waste. Such a combination is an excellent low-cost, easy, and prospective solution for the baking industry that could be applied to obtain bread with elevated nutritional value and enhanced health potential, as proven in this publication.

Developing lactic acid bacteria starter cultures for wholemeal rye flour bread with improved functionality, nutritional value, taste, appearance and safety.

Starter cultures composed of lactic acid bacteria (LAB) were developed based on the genotypic and phenotypic characterisation of isolates belonging to dominant groups of bacteria in spontaneous rye wholemeal sourdoughs. Combinations of strains have been evaluated on an industrial scale in the sourdough fermentation process. Wholemeal rye bread was prepared using sourdoughs obtained with 3 new starter cultures, and compared to bread made using the commercial culture (LV2). All newly developed cultures used for the preparation of wholemeal rye bread allowed to obtain better quality products as compared to the LV2 based bread. The best results were obtained when the culture containing Lactiplantibacillus plantarum 2MI8 and exopolysaccharide (EPS)-producing Weissella confusa/cibaria 6PI3 strains was applied. The addition of yeast during sourdough breads production, especially the one prepared from mentioned above starter culture, significantly improved their organoleptic properties, their volume and crumb moisture was increased, and also the crumb acidity and hardness was reduced. Fermentation of rye wholemeal dough, especially without the yeast addition, resulted in a significant reduction in the content of higher inositol phosphates as compared to the applied flour, which is associated with improved bioavailability of minerals. The results of this study prove that the investigated new starter cultures can be successfully applied in wholemeal rye bread production.

Bacterial community dynamics in spontaneous sourdoughs made from wheat, spelt, and rye wholemeal flour.

Sourdough fermentation is a traditional process that is used to improve bread quality. A spontaneous sourdough ecosystem consists of a mixture of flour and water that is fermented by endogenous lactic acid bacteria (LAB) and yeasts. The aim of this study was to identify bacterial diversity during backslopping of spontaneous sourdoughs prepared from wheat, spelt, or rye wholemeal flour. Culture-dependent analyses showed that the number of LAB (109  CFU/ml) was higher by three orders of magnitude than the number of yeasts (106  CFU/ml), irrespective of the flour type. These results were complemented by next-generation sequencing of the 16S rDNA V3 and V4 variable regions. The dominant phylum in all sourdough samples was Firmicutes, which was represented exclusively by the Lactobacillales order. The two remaining and less abundant phyla were Proteobacteria and Bacteroidetes. The culture-independent approach allowed us to detect changes in microbial ecology during the 72-hr fermentation period. Weissella sp. was the most abundant genus after 24 hr of fermentation of the rye sourdough, but as the process progressed, its abundance decreased in favor of the Lactobacillus genus similarly as in wheat and spelt sourdoughs. The Lactobacillus genus was dominant in all sourdoughs after 72 hr, which was consistent with our results obtained using culture-dependent analyses. This work was carried out to determine the microbial biodiversity of sourdoughs that are made from wheat, spelt, and rye wholemeal flour and can be used as a source of strains for specific starter cultures to produce functional bread.

Oat raw materials and bakery products - amino acid composition and celiac immunoreactivity.

BACKGROUND: The aim of this study was to compare the biochemical and immunochemical properties of avenins in some special oat raw materials and additionally the possibility of using them as a raw material for the gluten-free bakery products. METHODS: The compared oat raw materials were - oat flakes, commercial oat flours (including gluten-free oat flour) and residual oat flour, which is by-product of ß-glucan preparation. Biochemical characteristic included amino acid compositions and SDS-PAGE profiles of extracted avenins. The immunochemical reactivity with polyclonal anti-gluten and monoclonal anti-gliadin antibodies was evaluated qualitatively and quantitatively by immunoblotting and ELISA methods. Additionally, experimental bakery products made of examined raw materials were assessed according to their suitability for the celiac patients' diet. RESULTS: The highest protein content was measured in the ß-glucan preparation "Betaven" and gluten-free oat flour. Proteins of all materials are rich in glutamic and aspartic acid, leucine and arginine. Proportions of amino acids in avenins extracted from most of oat raw materials are similar, excluding gluten-free oat flour, which has a very low avenin content and proportions of individual amino acids are different. The SDS-PAGE protein pattern consisted of proteins with molecular weight of about 25-35 kDa. Polyclonal anti-gluten anti-body recognized all protein fractions of molecular weight higher than 20 kDa. Quantitative ELISA analysis shows that the majority of samples has a gliadin-like protein content within the range of 80-260 mg/kg, excluding gluten-free flours and corresponding bakery products. Altogether, ß-glucan preparation has extremely high level of gliadin-like proteins. CONCLUSIONS: In the examined oat raw materials and foods the contents of immunoreactive amino acid sequences exceeded the limit of 20 mg/kg (considered as gluten-free) except for gluten-free flours (oat and  the prepared mixture) and the bakery products based on gluten-free flours. Unfortunately, the rest of oat raw materials and products cannot be considered gluten-free.