Effect of whole amaranth flour on bread properties and nutritive value

This study investigated the effect of replacing wheat flour by whole. Amaranthus cruentus flour (up to 40 g/100 g) to evaluate its potential utility as a nutritious breadmaking ingredient. The incorporation of amaranth flour significantly increased protein, lipid, ash, dietary fibre and mineral contents. Breads with amaranth have significantly higher amounts of phytates and lower. myo-inositol phosphates, which could predict low mineral bioavailability at high levels of substitution (30-40 g/100 g). An increase in crumb hardness and elasticity was observed, and tristimulus colour values were significantly affected when the amaranth concentration was raised. Mineral contents, both micro- and macroelements, were increased significantly by the wheat flour substitution. Whole amaranth flour could be used as a partial replacement for wheat flour in bread formulations, increasing the product's nutritional value and raising dietary fibre, mineral and protein levels, with a significant slight depreciation in bread quality when used in proportions between 10 and 20 g/100 g. Thus, the inclusion of amaranth flour could be limited to a maximum proportion of 20 g/100 g, thereby maintaining both product quality as well as the nutritional benefit of this ingredient.This work was financially supported by projects AGL2006-09613/ALI, 200870I229, AGL2011-22669 and 2006PL0015 from the Ministry of Science and Innovation (MICINN), and PROMETEO/2012/064 from Generalitat Valenciana, Spain. The fellowship of J.M. Sanz Penella from MICINN is gratefully acknowledged.Peer Reviewe

Bean starch as ingredient for gluten-free bread

18 pages, 6 tables, 5 figures.-- Special Issue: Online Only Supplement.-- The definitive version is available at www3.interscience.wiley.comCommercially available gluten-free breads are of low quality and have a rapid staling during storage. Therefore, attempts were made to obtain gluten-free breads of improved structure properties and extended shelf life. For this purpose, laboratory-obtained bean starch, both native or hydrothermally modified, was added to a gluten-free formulation. Texture results revealed differences between the bottom (harder) and upper (softer) parts of fresh breads containing native bean starch. Modified starch reduced the hardness and diminished the differences between the upper and the bottom parts of a bread slice. Independent of storage duration, breads are crumbly. A considerable decrease of the peak and final viscosity was observed with the increase of the storage time in sample with native bean starch, whereas the presence of modified starch induced the opposite tendency. The addition of native starch increased the tendency of amylopectine to retrograde during storage, whereas the presence of modified starch decreased the retrogradation enthalpy by 16%.Peer reviewe

Effect of Starch Substitution by Buckwheat Flour on Gluten-Free Bread Quality

The buckwheat flour was studied as a potential healthy ingredient for improving the nutritional and technological quality of gluten-free bread. The effect of exchange of gluten-free formulation mass by buckwheat flour in 10, 20, 30 and 40 % was investigated. The increase in loaf specific volume with rising buckwheat flour addition was observed. Compared with the control sample, decrease in whiteness and increase in redness and yellowness of crumb were noticed. The rising amount of buckwheat flour in gluten-free bread formulation caused a decrease in crumb hardness during storage. This was in agreement with the decrease in starch gelatinisation enthalpy with the increasing amount of buckwheat flour in gluten-free formula in comparison with the control sample. Buckwheat flour could be incorporated into gluten-free formula and have a positive influence on bread texture and delaying its staling.This work was financially supported by 2006PL0015 Project (PAS from Poland, CSIC from Spain) and Consolider Fun-C-Food CSD2007-00063 from the Ministry of Science and Innovation (MICINN-Spain).Peer Reviewe

Ekstrudowane produkty z mąki gryczanej i jej zmieszania z białkami mleka. II. Charakterystyka chemiczna i właściwości fizykochemiczne białek oraz skrobi produktów ekstrudowanych z mąki gryczanej i jej mieszaniny z białkami mleka

The effect of extrusion on the chemical changes and physico-chemical properties of proteins and starch of buckwheat flour and its mixture with milk proteins was examined. It was found that the temperature of the process has an influence on the formatiron of starch-protein and starch-lipid complexes. The solubility and swelling power of starch was also changed.Ekstrudowanie mąki gryczanej lub jej mieszaniny z białkami mleka powoduje wiele zmian chemicznych i właściwości fizykochemicznych białek i skrobi. Nie stwierdza się obniżenia zawartości azotu ogólnego w produktach ekstrudowanych, natomiast obserwuje się wyraźne zwiększenie zawartości związków azotowych nierozpuszczalnych. Kolejnym dowodem zmian właściwości fizykochemicznych białek jest zmniejszenie się pola histerezy wyznaczonego w wyniku miareczkowania kwasem i zasadą zawiesiny białek produktu ekstrudowanego z mąki gryczanej. W przypadku zastosowania jako surowca mieszaniny mąki gryczanej z 25% dodatkiem białek mleka pola histerezy miareczkowania zwiększa się. Również wyniki rozdziału chromatograficznego na żelu Sephadex białek produktów ekstrudowanych wskazują na termolabilność białek gryki i możliwość ich agregacji z białkami mleka. Skrobia badanych produktów ekstrudowanych charakteryzuje się zmienionym składem chemicznym i właściwościami fizykochemicznymi w porównaniu ze skrobią ziarna gryki. W składzie chemicznym skrobi produktów ekstrudowanych zwiększa się zawartość związków azotowych, tłuszczowców wolnych i związanych oraz popiołu. W,skazuje to na możliwość tworzenia się kompleksów skrobiowa-białkowych i skrobiowo-tłuszczowych, które mają duże znaczenie w tworzeniu struktury i jej trwałości. W zakresie właściwości fizykochemicznych skrobi stwierdza się wysoki jej stopień kleikowania, zwiększanie się rozpuszczalności a obniżanie zdolności pęcznienia

Bean seed proteins digestibility affected by pressure and microwave cooking

The aim of the study was to compare the effect of pressure and microwave cooking on the in vitro protein digestibility of bean seeds (Phaseolus vulgaris) . The results of the in vitro digestibility ascertained the improvement of protein digestibility affected by pressure-cooking of seeds. The digestibility of proteins of microwave-cooked bean seeds was lower. The electrophoretic SDS-PAGE separation patterns of bean proteins hydrolysed with trypsin indicated a significant influence of both treatments on the proteins examined. Degradation of proteins was apparent, however, the dominant fraction of 47–41 kDa remained intact, which confirms its resistance to digestion

Permeation resistance in nanofiltration and high- pressure ultrafiltration of acidic whey processes

Analizowano zmiany szybkości i oporów permeacji w procesach nano- (NF) i wysokociśnieniowej ultrafiltracji (UF) serwatki kwasowej - produktu ubocznego po produkcji twarogów metodą tradycyjną. Zastosowano membrany rurkowe o różnej zdolności rozdzielczej (75% CaCl2 dla NF i 6 kDa dla UF). Otrzymano koncentraty o porównywalnej koncentracji wapnia i magnezu, ale tempo zmian szybkości i oporów permeacji było większe podczas nanofiltracji. Efekt ten przypisuje się szybkiemu formowaniu białkowej warstwy granicznej na powierzchni membrany w procesach UF.Rate changes and process resistance of permeation were analyzed during nano- (NF) and high-pressure ultrafiltration (UF) of acidic whey - by-product in traditional quark cheese manufacture. Tubular membranes of different selectivity (75% CaCl2 for NF and 6 kDa for UF) were applied. Re- tentates with comparable concentration of calcium and magnesium were obtained. However, in NF process the flux decline rate and the resistance increase with process time were greater. This effect is supposed to be caused by a rapid formation of protein layer at the membrane surface during U