Anna Nowotna

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.

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.

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.

Arabinoxylan-starch-protein interactions in specially modified rye dough during a simulated fermentation process

The purpose of the work was to determine which processes occur during fermentation of rye dough beside progressive hydrolysis of biopolymers and production of gases, and also to determine which compounds are most responsible for them. The study was conducted with a specially modified dough containing starch, arabinoxylan preparations (non-modified, hydrolysed and cross-linked) and protein obtained from rye wholemeal. Despite the same consistency of the dough samples, their viscosity and values of rheological parameters depended on the amount of arabinoxylan preparations and their molecular weight. Already at the stage of mixing the dough, high molecular complexes of arabinoxylan-protein and arabinoxylan-arabinoxylan were formed. Complex formation was confirmed in the modified dough preparation with rye starch including only arabinoxylan or rye protein as well as a combination of arabinoxylan and rye protein. The highest amount and molecular dimension of complexes were found in the sample composed of starch, cross-linked arabinoxylan and rye protein.