Hofmanová T., Hrušková M., Švec I. (2014): Evaluation of wheat/non-traditional flour composites. Czech J. Food Sci., 32: 288-295.We examine the nutritional effect of selected non-traditional grain samples added into wheat flour. In a form of flour, amaranth, quinoa, lupine, 5 hemp types, 2 teff types and 2 chia types were used for wheat flour substitution on a low and high level. Samples with amaranth and lupine flour showed the best improvement in terms of protein content (in the range between 21.1 and 26.0%). The highest total dietary fibre was found in lupine composites (7.1 and 9.8%). Hemp samples contained a significant amount of minerals in comparison with the control wheat sample (from 1.16% to 1.98%). According to the above-mentioned differences, flour composites containing single tested grains were distinguished by principal component analysis. All examined plant materials could be recommended for wheat flour fortification in terms of nutritional improvement. The addition of non-traditional flours partially changed both the volume and shape of laboratory prepared bread correspondingly to the type and added amount.

AbstractŠvec I., Hrušková M., Karas J., Hofmanová T. (2012): Solvent retention capacity for different wheats and flours evaluation. Czech J. Food Sci., 30: 429-437.The baking quality in the sets of both commercial and variety wheat samples (80 and 18 items) and wheat composite flour (standard and 25 blends) was evaluated in terms of the Solvent retention capacity method (AACC 56-11). Composites were prepared from a commercial fine wheat flour and commercial bio-wholemeal flour prepared by milling of common wheat, rye, oat, barleys and corn at substitution levels of 10, 20, 30, 40, and 50%. The commercial wheat quality testing ANOVA revealed the major effect of the sample tested form; the data measured for grain and flour proved to be correlated. Besides, the harvest year affected the baking quality to a greater degree than the growing locality. Within the variety wheat set, the harvest year factor dominated over that of the wheat cultivar one with the exception of the sodium carbonate retention capacity. In the case of the wheat flour substitution by bio-cereal flour types, the added amount of the alternative flour supported only the quantitative change caused by the incorporated cereal in all four retention capacities.

Smrčková P., Saglamtas M., Hofmanová T., Koláček J., Chena D., Šárka E. (2014): Effect of process parameters on slowly digestible and resistant starch content in extrudates. Czech J. Food Sci., 32: 503-508.A laboratory single-screw Kompaktextruder KE 19/25 was used at speeds 120-140 rpm of the screw with either a 2 : 1 or 3 : 1 compression ratio; the head had a 3 or 4 mm die. The temperature of the head was set at 131-144°C. The applied raw materials were maize grits, and mixtures with wheat starch, pea flour or chemically modified starch. Input mixtures differed in water addition (50 or 100 g water/kg). The highest amount of resistant starch (3.1% per total starch) in extrudate was found for mixture of pea flour and maize grits (with addition of 100 g water/kg of dry mixture), the output(extrudate)/input(mixture) ratio of the resistant starch was 45.8%. The highest SDS content was obtained for the maize grits and addition of 100 g water/kg using a die with a 3 mm diameter and a screw with a 3 : 1 compression ratio; the temperature of the head was approximately 140°C. Transportation rates: screw 140 rpm, dosing 15 rpm.

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Technological potential of four wheat-quinoa and wheat-canahua flour composites was evaluated in terms of pasting behavior. Wheat flour values of Zeleny sedimentation and Falling Number tests were decreased about 10%. Amylograph results were affected by low amylases activity in wheat flour as well as by high absorption capacity of canahua and quinoa -samples differed partly in temperature of gelatinization beginning. RVA profiles of pure flours differed clearly -both alternative materials did not demonstrate viscosity peak and differed in starch retrogradation rate during heating and cooling phase of the test. In combination with wheat flour, the profiles were influenced softly. Statistically significant differentiation was observed in the Peak Viscosities -the higher enhancement level, the lower value, as recorded especially for wheat-canahua blends. Principal component analysis verified a key importance of temperature of gelatinization beginning, viscosity maximum and proper temperature -RVA apparatus may serve as the first quick method for pasting behavior description.