Reaction of spring soft wheat to drought in the forest-steppe of the Trans-Urals

The purpose of the research is the reaction of spring soft wheat varieties to dry phenomena during the growing season in the forest-steppe zone of the Trans-Urals. Methods. The material was 24 varieties of various biotypes for maturation from the nursery of the competitive variety testing of the Kurgan Research Institute of Agricultural Sciences. Results. The negative effect of the drought reduced the yield in the experiments by 11.9 c/ha, the weight of 1000 grains by 5.7 g, and the nature by 19.7 g/l. The influence of grain size on the yield both in favorable years and in years of drought was noted (r = 0.63…0.98). In arid conditions, vitreous is correlated with yield, 1000 grain weight, in kind, to a lesser extent with gluten content, bread volume, and “flour strength”. The lack of moisture during the grain filling period increased the gluten content by 3.4 %, the quality by 15.1 e. p. IDC, the flour strength by 102.7 e. a., the volume of bread by 106 g/l. In favorable years, the weight of 1000 grains and the vitreous content of the grain correlate with gluten (r = 0.44; r = 0.24–0.84). Indicators of productivity and physical properties of grain increase when sowing at the optimal time, with a certain decrease in the gluten content (by 1.2 %), flour strength (by 5.3 e. a.), bread volume (by 73.2 e. p.). In the early sowing period, moisture deficiency reduces the indicators for all varieties Under these conditions, early-maturing varieties form a larger grain both when sowing at an early time (29.0 g) and when sowing at the optimal (31.3 g). In a drought, the role of the variety is especially high. High drought resistance was shown by the Zauralochka variety of the Kurgan Research Institute of Agriculture, which successfully passed the test in the dry years (2012, 2020) in the GSI system and in the environmental test (KASIB). The yield of the drought-resistant variety Zauralochka on average for the HSU was 20.2 c/ha, exceeding the standard Hercules by 2.2 c/ha. Scientific novelty. The features of the influence of dry phenomena on the yield and the main indicators of the quality of varieties are revealed, the correlation between them is determined. According to drought resistance, a variety of spring soft wheat Zauralochka was selected.

Quality of bread from flour of different spelt wheat varieties

Purpose. To study the quality formation in bread from different flour of spelt wheat (premium, whole-wheat) depending on the variety and line. Methods. Laboratory, mathematical and statistical, physical and chemical. Results. The bread volume made from high-grade flour varied from 303 to 523 cm3, which corresponds to 1.0–7.6 points depending on the variety and line of spelt wheat. The bread volume made from whole-wheat flour was 10–20% less than the bread volume made from premium flour. The average bread volume obtained from whole-wheat flour of ‘Zoria Ukrainy’ variety was 470 cm3, while low bread volume was obtained from flour of ‘Shvedska 1’ variety and LPP 3132, LPP 3117, TV 1100 lines which corresponded to 2.8–3.2 points. In other varieties and lines, these indicators were very low and ranged between 270 and 328 cm3 or less by 142–200 cm3 compared to the standard variety. The convexity of pan bread made from high-grade flour was the highest in ‘Zoria Ukrainy’ spelt wheat variety and NAK 34/12‑2 line: 0.49 and 0.54, respectively, which corresponded to 5.0 points. Significantly higher indicators were found in P 3, NAK34/12–2, and LPP 3122/2 lines: 0.38–0.51 (1.0–5.0 points). In ‘Shvedska 1’ variety and five lines, the indicator of bread convexity varied from 0.27 to 0.37 (from 3.0 to 4.0 points). In other varieties and lines it was significantly lower (0.07–0.21) than in the standard. The indicator of bread convexity from whole-wheat flour in ‘Zoria Ukrainy’ spelt wheat variety was 0.37 which corresponded to 4.0 points. Significantly higher indicators were found in P 3, NAK34/12–2 and LPP 3122/2 lines: 0.38–0.51 (1.0–5.0 points). In ‘Shvedska 1’ variety and five lines, the bread convexity indicator varied from 0.27 to 0.37, that corresponds to 3.0–4.0 points). In other varieties and lines it was significantly lower (0.07–0.21) than in the standard. Culinary quality of bread was high in all samples: 7.2–8.4 points (80–93% of the maximum value). However, the highest quality had the bread made from ‘Zoria Ukrainy’ variety, LPP 3132, NAK34/12–2, and TV 1100 lines. The overall culinary quality of whole-wheat bread was very high as it varied from 8.3 to 9.0 points. However, the bread made from ‘Shvedska 1’ variety and LPP 3117, LPP 3122/2, P 3, LPP 3132, NAK34/12–2 lines had the highest quality (9.0 points). Conclusions. Gloss index of bread surface and its overall estimate is affected by the protein content in grain. Gluten content has a slightly smaller effect on bread quality. In addition, crust surface, bread texture, the overall estimate of bread quality is also affected by the gluten deformation index. Bread obtained from ‘Zoria Ukrainy’ flour, LPP 3132, NAK34/12–2, and TV 1100 lines had the highest overall culinary evaluation.

Protein Enrichment of Wheat Bread with Microalgae: Microchloropsis gaditana, Tetraselmis chui and Chlorella vulgaris

Cell wall disrupted and dried Microchloropsis gaditana (Mg), Tetraselmis chui (Tc) and Chlorella vulgaris (Cv) microalgae biomasses, with or without ethanol pre-treatment, were added to wheat bread at a wheat flour substitution level of 12%, to enrich bread protein by 30%. Baking performance, protein quality and basic sensory properties were assessed. Compared to wheat, Mg, Tc and Cv contain higher amounts of essential amino acids and their incorporation markedly improved protein quality in the bread (DIAAS 57–66 vs 46%). The incorporation of microalgae reduced dough strength and bread volume and increased crumb firmness. This was most pronounced for Cv and Tc but could be improved by ethanol treatment. Mg gave adequate dough strength, bread volume and crumb structure without ethanol treatment. To obtain bread of acceptable smell, appearance, and colour, ethanol treatment was necessary also for Mg as it markedly reduced the unpleasant smell and intense colour of all algae breads. Ethanol treatment reduced the relative content of lysine, but no other essential amino acids. However, it also had a negative impact on in vitro protein digestibility. Our results show that Mg had the largest potential for protein fortification of bread, but further work is needed to optimize pre-processing and assess consumer acceptance.

Drought Stress during Anthesis Alters Grain Protein Composition and Improves Bread Quality in Field-Grown Iranian and German Wheat Genotypes

Drought stress is playing an increasingly important role in crop production due to climate change. To investigate the effects of drought stress on protein quantity and quality of wheat, two Iranian (Alvand, Mihan) and four German (Impression, Discus, Rumor, Hybery) winter wheat genotypes, representing different quality classes and grain protein levels, were grown under field conditions in Eqlid (Iran) during the 2018–2019 growing season. Drought stress was initiated by interrupting field irrigation during the anthesis phase at two different stress levels. Drought stress at anthesis did not significantly change total grain protein concentration in any of the wheat genotypes. Similarly, concentrations of grain storage protein sub-fractions of albumin/globulin, gliadin and glutenin were unaltered in five of the six genotypes. However, analysis of protein sub-fractions by SDS polyacrylamide gel electrophoresis revealed a consistent significant increase in ω-gliadins with increasing drought stress. Higher levels of HMW glutenins and a reduction in LMW-C glutenins were observed exclusively under severe drought stress in German genotypes. The drought-induced compositional change correlated positively with the specific bread volume, and was mainly associated with an increase in ω-gliadins and with a slight increase in HMW glutenins. Despite the generally lower HMW glutenin concentrations of the Iranian genotypes and no effect of drought on the concentration of HMW sub-fraction, there was still high specific bread volume under drought. It is suggested that for the development of new wheat cultivars adapted to these challenging climatic conditions, the protein composition should be considered in addition to the yield and grain protein concentration.

Texture design of gluten-free bread by mixing under controlled headspace atmosphere

Gluten-free breads often show a reduced specific bread volume, in comparison to gluten-containing products, caused by non-adapted processing technologies of gluten-free dough. In this investigation, different mixing speeds and durations (600–3000 rpm for 3 min, 5 min or 8 min, respectively) as well as variations in the pressure (prel – 50 to prel + 130 kPa) in the headspace atmosphere during mixing (Stephan mixer) and pressure ratios of overpressure/negative pressure of 8 min mixing (20/80, 50/50, 80/20) were studied to determine their impact on the gas volume fraction of dough and specific volume of breads. A pressure rise of prel 50 kPa, prel 100 kPa or prel 130 kPa increased the gas volume fraction in dough of 60%, 100% or 120%, respectively, and led to a significant higher specific bread volume (7%) and the reduction of crumb hardness (35%) at prel 130 kPa. A linear correlation (R2 = 0.843) between the pressure and specific volume of breads was found. An extended first mixing phase at overpressure resulted in the formation of a very fine pore structure, whereby a short overpressure phase caused the formation of big pores. Thus, the control of the headspace atmosphere during mixing is a suitable parameter to adjust the density of dough and consequently, the pore size distribution for a specific texture design.

The Effect of α-, β- and γ-Cyclodextrin on Wheat Dough and Bread Properties

Cyclodextrins (CDs) are cyclic oligosaccharides that have found widespread application in numerous fields. CDs have revealed a number of various health benefits, making them potentially useful food supplements and nutraceuticals. In this study, the impact of α-, β-, and γ-CD at different concentrations (up to 8% of the flour weight) on the wheat dough and bread properties were investigated. The impact on dough properties was assessed by alveograph analysis, and it was found that especially β-CD affected the viscoelastic properties. This behavior correlates well with a direct interaction of the CDs with the proteins of the gluten network. The impact on bread volume and bread staling was also assessed. The bread volume was in general not significantly affected by the addition of up to 4% CD, except for 4% α-CD, which slightly increased the bread volume. Larger concentrations of CDs lead to decreasing bread volumes. Bread staling was investigated by texture analysis and low field nuclear magnetic resonance spectroscopy (LF-NMR) measurements, and no effect of the addition of CDs on the staling was observed. Up to 4% CD can, therefore, be added to wheat bread with only minor effects on the dough and bread properties.

Coffee Cherry Pulp by-Product as a Potential Fiber Source for Bread Production: A Fundamental and Empirical Rheological Approach

Effects of substituting of wheat flour with coffee cherry pulp powder (CCPP) (coffee by-product as fiber source) at 0, 1.2, 2.3, and 4.7% dry basis (0, 1.25, 2.5, and 5% wet basis) on dough and gluten rheological properties and baking quality were investigated. Rheological properties were analyzed during mixing, compression recovery, and creep-recovery. A rheological approach was adopted to study the viscoelasticity of dough enriched with fiber. The data obtained were analyzed with the Kelvin–Voigt model and the parameters were correlated to bread volume and crumb firmness to assess the effect of incorporating CCPP. A decrease in gluten’s elastic properties was attributed to the water-binding and gelling properties of CCPP. Stiffness of dough and crumb firmness increased as the level of CCPP increased and bread volume decreased. Stiffer dough corresponded with lower compliance values and higher steady state viscosity compared to the control. A follow-up study with 5% CCPP and additives is recommended to overcome the reduction in elastic recovery and bread volume.

A Comparative Assessment of the Baking Quality of Hybrid and Population Wheat Cultivars

The study assessed the quality parameters of grain and flour, the rheological properties of dough and the quality of bread prepared from flour of hybrid cultivars of wheat in comparison with population cultivars of wheat. As the interest in wheat hybrids cultivars from the agricultural and milling industry is growing, their technological value of grain and flour was evaluated at two levels of nitrogen fertilisation (N1—110 kg/ha, N2—150 kg/ha). Increasing the fertilisation (N2) produced a significant influence on the crude protein and gluten content in the flour, as well as the moisture of the crumb and the yield of the dough without impacting other rheological traits and parameters of bread baking process. The performed principal component analysis (PCA) allowed for identification of the best cultivars among the studied wheat cultivars (Hybery and Hyvento). The hybrid cultivar Hyvento was characterised by favourable qualitative traits of the grain (vitreousness, crude protein content) and rheological parameters of the dough (bread volume), however, it had lower baking quality parameters. Among the hybrid cultivars, the best applicability for baking purposes was Hybery due to the favourable values of the baking process parameters and bread quality (bread yield, bread volume, Dallmann porosity index of crumb). Hybrid cultivars of wheat can therefore be used for the production of bread and be an alternative in agricultural production for population cultivars, which will contribute to filling the knowledge gap for the hybrid wheat cultivars.

Effects of Combined α-Amylase and Endo-Xylanase Treatments on the Properties of Fresh and Frozen Doughs and Final Breads

Frozen bread doughs usually exhibit less bread volume and poor texture due to dough weakening as well as reduced yeast viability. The objectives of this study were to improve the textural properties of frozen bread dough by applying carbohydrate-active enzymes, α-amylase and endo-xylanase. Each enzyme was applied to dough formulation at 20 (748 and 3.5 units, respectively) and 100 ppm levels of flour, and their combined treatments were also applied. Enzyme-treated doughs were kept frozen at −20 °C for 2 weeks, and then baked following the official American Association of Cereal Chemists (AACC) method. A texture profile analysis of oven-baked breads was performed at 25 °C after a 5-day storage period. α-Amylase treatment at a 100 ppm level increased the specific bread volume by 24.5% and 21.9% when compared to untreated fresh and frozen bread doughs, respectively, and decreased crumb hardness by 63.4% and 58.3%; endo-xylanase (100 ppm) also decreased crumb hardness by 56.9% and 26.9%. The combined use of α-amylase and endo-xylanase retarded bread hardening synergistically after a 5-day storage period.