Rafał Ziobro

Effect of inulin on rheological and thermal properties of gluten-free dough.

The aim of the study was to evaluate the influence of inulins with varying degree of polymerization on rheological and thermal properties of gluten-free starch-based dough. The share of inulin reduced the values of consistency coefficient, as well as storage and loss moduli, and increased creep compliance. Inulin preparation with the highest average degree of polymerization had the strongest impact on viscoelastic properties of the obtained dough. The presence of inulin also caused a significant decrease of viscosity upon pasting, and an increase of gelatinization temperatures TOg, TP1g, TP2g, and TEg. Addition of inulin had no effect on gelatinization enthalpy (ΔHg), while it strongly reduced the enthalpies of retrograded amylopectin after storage. Water binding properties of inulin seem to be the key factor, responsible for modification of dough properties, because they influence solvent availability for other constituents of such system.

Quality of gluten-free supplemented cakes and biscuits

Gluten-free confectionery products were used as controls for comparison with the products, which included different supplements such as linseed meal, amaranth and/or buckwheat. The latter were expected to increase nutritional values of confectionery products. Cookies were analyzed in terms of volume, selected textural parameters (hardness, cohesiveness), organoleptic quality, shelf-life, and different chemical components. All supplemented gluten-free products received high consumer scores, exceeding in some cases those of control samples. Supplementation of gluten-free confectionery products with linseed meal, amaranth and/or buckwheat flours enhanced their final nutritional quality. A significant rise was observed in the protein content and dietary fiber, and in the case of linseed meal also α-linolenic acid. All of the supplemented gluten-free confectionery products contained more macro-elements and micro-elements (i.e. potassium, phosphorus, magnesium, calcium, iron, manganese, zinc and copper), as compared with the controls. Taking into account the amino-acid composition, amaranth proved a more beneficial supplement of gluten-free products than linseed.

The influence of acorn flour on rheological properties of gluten‑free dough and physical characteristics of the bread

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.

Application of cross-linked and hydrolyzed arabinoxylans in baking of model rye bread.

The role of water extractable arabinoxylan with varying molar mass and structure (cross-linked vs. hydrolyzed) in the structure formation of rye bread was examined using a model bread. Instead of the normal flour, the dough contained starch, arabinoxylan and protein, which were isolated from rye wholemeal. It was observed that the applied mixes of these constituents result in a product closely resembling typical rye bread, even if arabinoxylan was modified (by cross-linking or hydrolysis). The levels of arabinoxylan required for bread preparation depended on its modification and mix composition. At 3% protein, the maximum applicable level of poorly soluble cross-linked arabinoxylan was 3%, as higher amounts of this preparation resulted in an extensively viscous dough and diminished bread volume. On the other hand highly soluble, hydrolyzed arabinoxylan could be used at a higher level (6%) together with larger amounts of rye protein (3% or 6%). Further addition of arabinoxylan leads to excessive water absorption, resulting in a decreased viscosity of the dough during baking and insufficient gas retention.

Rye flour enriched with arabinoxylans in rye bread making

The aim of the study was to investigate physical and chemical properties of preparations of water soluble arabinoxylans (arabinoxylan-enriched flour) obtained by industrial method and their derivatives (obtained by hydrolysis and cross-linking of aranbinoxylans), as well as their impact on baking properties of rye flours. Additionally, these results were compared with highly purified arabinoxylans prepared by laboratory method and well characterized in the literature. Flour enriched with arabinoxylans was obtained by industrial method involving air separation of flour particles. It was characterized by 8.6% arabinoxylan content, lack of insoluble material and substantial residue (67%) of starch and dextrins. The addition of all industrial method preparations in amount of 10% (i.e. approx. 1% water soluble arabinoxylans), to rye flours resulted in an increase in water absorption, bread volume and decrease in hardness of the bread crumb and the effect was especially strong in the case of flour type 720. Due to the easiness of isolation procedure, industrial method preparation could be advised as an improver for rye bread making.

The influence of extrusion process on myo-inositol phosphate content and profile in snacks containing rye bran

The analysis of phytates in extrudates containing rye bran was done by a colorimetric method with the Wade reagent. The changes in profiles of myo-inositol phosphates indicate that, although no isomers with positive physiological functions (such as I(1,4,5)P3, I(1,2,3)P3 or I(1,3,4,5)P4) were formed, the beneficial impact of extrusion is the reduction of phytates, as compared to the raw material. The obtained snacks containing rye bran received acceptable to desirable sensory scores.

Gluten-free bread with an addition of freeze-dried red and purple potatoes as a source of phenolic compounds in gluten-free diet

Abstract The basis for gluten-free diet is often gluten-free bread, which is usually characterized by a low-nutritional value, and lacks any pro-health properties. Only after an introduction of gluten-free raw materials, containing high level of bioactive compounds it would be possible to obtain the product with a pro-health potential. The aim of the study was to analyze the content of bioactive compounds (total phenolic content, phenolic acids, flavonoids, flavonols, anthocyanins and carotenoids) in gluten-free bread prepared with 5% addition of freeze-dried red and purple potatoes as well as to assess their antioxidant potential. Summarizing, among the analyzed gluten-free breads with an addition of freeze-dried red and purple potatoes, the best results could be obtained by using variety Magenta Love (red potato), which provided the highest levels of phenolic compounds and carotenoids and also antioxidant and antiradical activity.

Usability of residual oat flour in the manufacture of extruded corn snacks

Extrusion technology is used to produce snacks from various raw materials, including by-products. One such by-product is residual oat (Avena sativa L.) flour (ROF), which is obtained as a by-product in the production of Betaven. The aim of this study was to prepare extrudates based on cornmeal with varying proportions of ROF, and to investigate the influence of applied additives on nutritional and pro-health compounds and the texture and functional properties of the snacks. Cornmeal extrudates with varying proportions of ROF were analyzed. Products obtained at a 1:2 compression ratio with 10% ROF exhibited the highest expansion, least density and hardness, and the highest water-binding capacity. The use of a 10% addition level caused an increase in soluble dietary fiber by 63%, insoluble fiber by 25%, polyphenols by 23%, and antioxidant activity by 22%. The above-mentioned extrudates had the best sensory quality, and therefore this level of ROF addition is recommended for industrial processing.

Fermat’s Little Theorem via Divisibility of Newton’s Binomial

Abstract Solving equations in integers is an important part of the number theory [29]. In many cases it can be conducted by the factorization of equation’s elements, such as the Newton’s binomial. The article introduces several simple formulas, which may facilitate this process. Some of them are taken from relevant books [28], [14]. In the second section of the article, Fermat’s Little Theorem is proved in a classical way, on the basis of divisibility of Newton’s binomial. Although slightly redundant in its content (another proof of the theorem has earlier been included in [12]), the article provides a good example, how the application of registrations could shorten the length of Mizar proofs [9], [17].

Some Remarkable Identities Involving Numbers

Summary The article focuses on simple identities found for binomials, their divisibility, and basic inequalities. A general formula allowing factorization of the sum of like powers is introduced and used to prove elementary theorems for natural numbers. Formulas for short multiplication are sometimes referred in English or French as remarkable identities. The same formulas could be found in works concerning polynomial factorization, where there exists no single term for various identities. Their usability is not questionable, and they have been successfully utilized since for ages. For example, in his books published in 1731 (p. 385), Edward Hatton [3] wrote: “Note, that the differences of any two like powers of two quantities, will always be divided by the difference of the quantities without any remainer...”. Despite of its conceptual simplicity, the problem of factorization of sums/differences of two like powers could still be analyzed [7], giving new and possibly interesting results [6].