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Food texture is traditionally evaluated using texturometers. On a pilot scale, four samples of graham or cheese salted sticks were measured by using the apparatus Extensograph-E. The equipment is originally designed for evaluation of the viscoelastic properties of wheat flour dough. The extensograph resistance as the height of gained curves has been closely correlated with the weight of the broken samples (ranges 59-1506 units and 3.11-19.38 g, respectively), representing the hardness of the salted sticks. As presumed, extensigraph elasticity and curve width were measured at close intervals 5.00-10.00 mm due to brittle character of the material tested. Similarly, neither the deformation energy as the area under the curve could be used for the samples discrimination (range 0.59-11.00 cm2). The hardness of cheese type and graham counterpart was statistically similar – the extensograph resistance means of fifty items were 559±381 and 500±352 units. According to the producer, the least, both tested graham stick samples could be differentiated - the corresponding means of fifty items were 367±293 and 632±361 units). Finally, only the extensibility of salted sticks was correlated with the declared contents of saccharides, proteins, and fat (r = −0.52, −0.56, and 0.49 for N = 100 and P = 95%).

Wheat sourdough was prepared from white wheat flour, tap water, commercial mixed sourdough starter, using an industrial pilot fermenter (8 h fermentation time). In addition to common quality parameters of the sourdough, such as the titratable acidity and pH, the viscosity was measured stepwise using the viscometer. After 8 hrs fermentation, higher final viscosity than the initial one was observed. The correlation analysis confirmed the known relationship between the fermentation time of the sourdough, the pH and the titratable acidity. Пшеничная закваска была приготовлена из белой пшеничной муки, воды, коммерческой закваски с использованием пилотного ферментера (время ферментации составляло 8 ч.). В дополнение к традиционным качественным параметрам закваски, таким как титруемая кислотность и pH, с помощью вискозиметра ступенчато измеряли вязкость. После 8 часов ферментации конечная вязкость была выше, чем начальная. Корреляционный анализ результатов подтвердил известную взаимосвязь между временем ферментации закваски, pH и титруемой кислотностью. Пшеничну закваску готували з білого пшеничного борошна, води, комерційної закваски з використанням пілотного ферментатора (час бродіння складав 8 год). На додаток до загальних параметрів якості закваски, таких як титрувана кислотність і рН, допомогою віскозиметра вимірювали в’язкість. Після 8-годинної ферментації спостерігається вища кінцева в'язкість, ніж початкова. Кореляційний аналіз підтвердив відомий зв'язок між часом бродіння закваски, рН і титрованою кислотністю.

The study compares the influence of wheat flour replacement by 10 or 20 wt% of quinoa and canahua wholemeals on wheat dough technological quality and rheological properties. The technological quality of wheat flour was affected in terms of protein quality and amylases activity, associated with a high dietary fibre content of both tested non-traditional materials. A farinograph test revealed that quinoa partially increased water absorption; a higher amount of water resulted in the shortened stability of dough consistency during mixing and its weakened cohesiveness at the end of the test. The effect of canahua was unequivocal – water absorption decreased, stability was prolonged properly, but dough softening increased. An extensigraph test confirmed a positive effect of alternative crops on dough elasticity, but in general, the composite dough with 20% of canahua or quinoa showed worsened machinability. Multivariate statistical methods proved a stronger effect when quinoa was analysed solely than when added at complete samples a set, while for canahua-wheat samples the result was opposite.

Fruiting bodies (basidiocarps) of the cultivated mushroom Pleurotus ostreatus (16 strains) were characterized by vibration spectroscopy and chemometrics. According to organic elemental analysis and Megazyme assay, the basidiocarps contained ~6.2&ndash, 17.5% protein and ~18.8&ndash, 58.2% total glucans. The neutral sugar analysis confirmed that glucose predominated in all the samples (~71.3&ndash, 94.4 mol%). Fourier-transformed (FT) mid- and near-infrared (FT MIR, FT NIR) and FT Raman spectra of the basidiocarps were recorded, and the characteristic bands of proteins, glucans and chitin were assigned. The samples were discriminated based on principal component analysis (PCA) of the spectroscopic data in terms of biopolymeric composition. The partial least squares regression (PLSR) models based on first derivatives of the vibration spectra were obtained for the prediction of the macromolecular components, and the regression coefficients R2 and root mean square errors (RMSE) were calculated for the calibration (cal) of proteins (R2cal 0.981&ndash, 0.994, RMSEcal ~0.3&ndash, 0.5) and total glucans (R2cal 0.908&ndash, 0.996, RMSEcal ~0.6&ndash, 3.0). According to cross-validation (CV) diagnosis, the protein models were more precise and accurate (R2cv 0.901&ndash, 0.970, RMSEcv ~0.6&ndash, 1.1) than the corresponding total glucan models (R2cv 0.370&ndash, 0.804, RMSEcv ~4.7&ndash, 8.5) because of the wide structural diversity of these polysaccharides. Otherwise, the Raman band of phenylalanine ring breathing vibration at 1004 cm&minus, 1 was used for direct quantification of proteins in P. ostreatus basidiocarps (R ~0.953). This study showed that the combination of vibration spectroscopy with chemometrics is a powerful tool for the evaluation of culinary and medicinal mushrooms, and this approach can be proposed as an alternative to common analytical methods.

To elevate dietary fibre content in wheat bread, two additions of barley flour were tested (30 % and 50 %), and further 5 % or 10 % of chia or teff wholemeals. Chia elevated dietary fibre content more effectively than teff did (up to 6.41 % and 4.29 %, respectively). Non‑gluten nature of proteins in non‑traditional raw materials also affected farinograph, amylograph and mixolab proof results. Water absorption increased about 10 % in total, especially owing to teff presence in composite flour. All three alternative crops decelerated dough development and prolonged its stability, but dough softening degree depended on their combination. Higher water absorption was reflected in viscosity rise during amylograph testing. Using mixolab equipment, significantly more accurate differentiation of tested composites was reached, both in phase of dough kneading and registration of viscosity during heating and cooling. Contrary to this, any statistically verifiable difference was observed between chia or teff wholemeal variants from white of dark seeds. By variance analysis, some rheological parameters (dough softening degree, torque point C5, mixolab energy) together with specific bread volume were identified as principal for samples distinguishing. In terms of flour and bread quality, barley flour portion had a prevailing effect for chia tri‑composites. Reversely, quality of flour blends containing teff was dependent on both barley flour and teff wholemeal portion and type.

Additions of barley flour alone or with combination of chestnut and acorn flour (30%; 30+5%; 30+10%) were aimed at increasing the dietary fibre content in wheat bread. In this regard, enhancement by acorn flour elevated the dietary fibre by a greater extent (up to 7.80%) compared to barley or chestnut flours. Increasing the proportion of non-traditional raw materials also influenced flour pasting properties during the amylograph test as well as the farinograph and extensigraph properties of non-fermented dough. In contrast to the wheat flour, analysis of Falling Number and Zeleny values showed a decrease in technological potential of flour composites of approximately 30%. Water absorption increased about 2 percentage points, mainly with enhancement by chestnut flour. All the non-traditional raw materials slowed dough development, whilst dough softening degree differed according to actual composition. Dough viscous and elastic properties worsened as shown by a decrease in energy absorbed, depending on the type and the addition of the non-traditional products. Changes in flour composition were reflected in amylograph viscosity maximum, which became lower with increasing amounts of chestnut and acorn flour. A significant worsening of the bread specific volume as well as of bread shape (vaulting) corresponded with a partial dilution of the gluten matrix. Compared to the wheat bread, 10% chestnut flour caused bread size to diminish to less than one half of the wheat loaf. Statistically, the principal features were water absorption, dough softening degree and extensigraph energy together with specific bread volume. In terms of wheat flour and bread quality, the influence of barley flour overcame the effects of adding chestnut or acorn flours.

Wholemeal flours from various cereals and pseudocereals are a valuable source of nutritionally important fiber components, especially beta-glucans and arabinoxylans, as well as bioactive substances accompanying dietary fiber. Most types of whole-wheat flours have unfavorable baking and sensory properties. The finest granulation of bran particles in the flour has a significant effect on reducing or eliminating these deficiencies. Special disintegration equipment is required to achieve fine granulation of the bran particles. In this study, we have tested a special type of impact mill (originally intended for grinding of plastics) to produce special finely ground wholemeal flours with lower starch damage and higher farinographic absorption. Moisture content in the studied flours was significantly lower (7.4–9.8%) than is common in standard flour (13–14%). According to the results of flour analyses obtained from several cereal sources, it seems that especially in rye and wheat, this technology is suitable for both achieving fine granulation of bran particles and in terms of not very substantial damage of starch granules.

Wheat flour was fortified by 2.5 or 5.0 wt. per cent of linseed fibre, gained from seeds of golden flax varieties Amon and Raciol and brown one Recital (granulation 500 - 700 m), prepared from 2015 harvest. Technological quality of six flour composites was described analytically by Falling Number and Zeleny sedimentation test. Both screening methods shown a little impact on amylases activity and protein quality, respectively. Rheological tests included the farinograph, the extensigraph and the Rapid Visco Analyser (RVA) proofs. Additions of brown and yellow flax fibre significantly increased farinograph water absorption and shortened dough stability, somewhat stronger by addition of brown linseed fibre. Extensigraph curves course depended on dough resting time, higher differences between wheat control and flour composites were observed after 60 min dough resting. Linseed fibre supported dough extensibility, and energy as area under curve significantly decreased about 7 - 18%, mainly due to increasing alternative material portion in dough. In general, fibre is characterised as hydrophilic material, and pasting profiles of flour composites confirmed this experience. During dough leavening, tested samples were differentiated according to maturograph dough resistance; optimal leavening time of wheat-linseed fibre dough was shorter than control. Regardless described modifications in dough machinability, specific volumes of bread buns were similar though whole sample set. A weak worsening of buns vaulting reflected a partial dilution of dough gluten skeleton. Cut-off biscuits were characterised by gradually lowering spread ratio, correspondingly to elevated dough elasticity. Laboratory prepared elbow-pasta have the same cooking time as the control (8.0 min), and data variation could not be attributed to linseed fibre or addition level. All three cereal products were found to have acceptable sensory profiles. PCA method verified partial lowering of protein quality and pointed at tested sample differentiation according to linseed addition level.

Wheat flour substitution by barley one led to shortening of fermentation and leavening times (about 14–57% and 35–83%, respectively) as well as to lessening of dough volumes (about 25–75%), based on lowered protein quality (Zeleny value). Addition of barley flour affected specific bread volume; diminishing for wheat-barley blends 70:30 and 50:50 reached 30% and 43%, respectively. Volume of bread prepared from wheat-barley blend 70:30 enhanced by dehulled hemp wholemeal was the highest within the tested tri-composites set, achieving 130% of wheat-barley control; other hemp products caused the parameter decrease (from 8 to 33%). Within a group of bakery products containing 50% of barley flour, hulled hemp wholemeal partially supressed negative effect of barley flour – specific bread volumes increased about ca 15%. Commercial fine hemp flour samples demonstrated a reversal influence – its addition resulted into lower buns size than wheat-barley control (about 3–34%). Between wheat flour and both groups of flour tri-composites, PCA confirmed differences in dough and bread technological quality. Specific bread volume could be predicted according to maturograph dough elasticity, dough or bread OTG volumes.

Two types of yellow and brown linseed, differing in granulation, were tested in form of wheat flour composites (additions 2.5% and 5.0%) by using the Farinograph, the Extensigraph and the Rapid Visco Analyser (RVA) apparatuses. Additions of brown and yellow flax fibre significantly affected Falling Number and Zeleny test values. Curves of farinograph were differed according to flax fibre type - finer flax (better terminology) granulation meant somewhat stronger negative changes in dough stability and dough softening degree. Results of extensigraph test demonstrated changes in dough elasticity and extensibility due to lowering of gluten protein content. Appearance of the RVA profiles was verifiably different, reflecting diverse wheat and flax polysaccharides, added dietary fibre type and its granulation. Due to that, bread volume and shape was lowered up to one-half in case of golden flax composites. Similar tendencies with smaller negative influence caused the brown linseed. Fibre from flax is used for technical (textile) use, but linseed dietary fibre addition affected quality of laboratory prepared cut-off biscuits and dried pasta differently, showing a dependence on the fibre type, granulation as well as addition level. Sensory profiles of all mentioned product types were acceptable.

White or black chia seeds, substituting 2.5% or 5.0% of wheat flour in prepared blends, were treated by milling, hydration, or combination of both. In terms of ash and protein contents, chia addition influenced chemical composition in higher extent than its type – increases up to about 0.5% and 1.3%, respectively, were evaluated. Protein quality was diminished to 35% in maximum, within any impact of chia type. A higher chia addition raised total dietary fibre content almost about one half (from 3.21% to 4.58%). White chia caused gradual lowering of amylases activity, while its dark type had insignificant effect. Composite bread volumes overcame the control one about 6–30%; positive chia effect has risen in order of forms whole hydrated (+9% in average), hydrated milled chia (+20%) and milled dry chia (+29%). As presumed, crumb firmness corresponded to bread volumes (r = 0.83, P = 99.9%), demonstrating ease of crumb mastication.

To elevate dietary fibre content in wheat bread, additions of barley flour were tested (30%) alone, and in combination with 5% or 10% of chestnut and acorn flour. Acorn flour elevated dietary fibre content more effectively than the chestnut flour did (TDF up to 7.8%). Non-gluten nature of proteins in non-traditional raw materials also affected farinograph, extensograph and amylograph features, used for predicting bakery procedure. Technological parameters (Falling Number, Zeleny sedimentation value) decreased to nearly 30% compared to the wheat flour. Water absorption increased about 2% in total, especially owing to the chestnut presence in the composite flour. All three alternative crops slowed dough development, but the dough softening degree depended on their combination. Viscoelastic behaviour has worsened (mainly parameter extensograph energy), depending on the type and the addition of the non- traditional products in the tested mixtures. Changes of suspension structure were reflected in maximum viscosity, which became lower during the amylograph test. A significant worsening of the buns specific volume and vaulting reflected a partial dilution of the gluten network of the dough. The highest addition of the chestnut flour in the recipe caused a decrease to less than one half compared to the wheat product. By the principal component analysis, some rheological parameters, together with specific bread volume, were identified as principal for sample distinguishing. In terms of wheat flour and bread quality, barley flour addition in the mixtures had a prevailing effect on the tested tri-composites.

Model cereal blends were prepared from commercial wheat fine flour and 5 samples of hemp flour (HF), including fine (2of conventional form, 1 of organic form) and wholemeal type (2 of conventional form). Wheat flour was substituted in 4levels (5, 10, 15, 20%). HF addition has increased protein content independently on tested hemp flour form or type. Partial model cereal blends could be distinguished according to protein quality (Zeleny test values), especially between fine and wholemeal HF type. Both flour types affected also amylolytic activity, for which a relationship between hemp addition and determined level of Falling Number was confirmed for all five model cereal blends. Solvent retention capacity profiles (SRC) of partial models were influenced by both HF form and type, as well as by its addition level. Between both mentioned groups of quality features, significant correlation were proved - relationships among protein content/quality and lactic acid SRC were verifiable on p (-0.58, 0.91, respectively). By performed ANOVA, a possibility to distinguish the HF form used in model cereal blend according to the lactic acid SRC and the water SRC was demonstrated. Comparing partial cereal models containing fine and wholemeal hemp type, HF addition level demonstrated its impact on the sodium carbonate SRC and the water acid SRC.

Hemp flour composition (20–30% proteins, 7–13% fat and more than 40% saccharides) is a precondition for its usage into non-traditional cereal products. Corresponding to the fact, that hemp proteins are represented mostly by edestin, a low-molecular globulin, technological behaviour of composites containing 5–20% of hemp flour is basically different. The effect was clearly reflected in specific bread volume decrease, comparing standard wheat bread vs. wheat-hemp one. Sensorial profile of such fortified product depends on hemp sample origin, the better one was observed for dehulled wholemeal hemp flour addition. Image analysis of black-white bread cut prints revealed increasing pore densities (up to about 74%) at reversely diminishing mean cell areas (up to about 31%) for bread altered by hulled wholemeal hemp flour. Comparing to wheat standard W2, crumb appearance of bread enhanced by 5% and 20% of dehulled hemp wholemeal was described by conversely lower cell density (11 and 9 vs. 13 pores per cm2) with verifiably larger cells (3.13 a 4.25 mm2 against 2.35 mm2). Specific bread volume and crumb penetration were significantly correlated to both cell density (r −0.69 and −0.65, respectively; P = 99.9 %) and to cell mean area (0.79 and 0.69, respectively; P = 99.9 %).

Svec I., Hruskova M., Karas J., Hofmanova 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.

Summary Technological quality in the sets of eighty commercial wheat samples was evaluated by grain milling traits (test weight, thousand kernel weight, grain hardness as Particle Size Index, one-stream flour yield) and common analytical parameters (wet gluten and protein contents, Zeleny test value, falling number) together with the solvent retention capacity (SRC) method (AACC 56-11). For the commercial wheat, the latter analytical procedure (originally designed for flour quality analysis) was verified also for grain wholemeal. Within the mentioned sample group, anova revealed the strongest effect of the harvest year, both for milling and for technological parameters. For the SRC profiles, the effect of the sample form used dominated the crop year influence. The grain SRCs were correlated with the milling traits foursome, while an agreement between the flour SRC profiles and technological quality data was not so tight. However, the flour lactic acid SRC was associated with the wet gluten and protein contents (r = 0.24, P

Wheat/hemp and wheat/teff model composites were prepared as 90:10 and 80:20 w/w blends, using two different Czech commercial wheat flour samples (standards M, M1) and bright/dark forms of these non-traditional crops flour. The objective of this study was to determine the effect of alternative flour samples on the blend compositional profiles including dietary fibre content, on the technological quality described by modern Solvent Retention Capacity method and on laboratory baking test results. According to seeds composition, nutritional flour enrichment reached higher levels of protein (from approx. 13.0% about 30% vs. 6%) and fibre contents (from approx. 3.3% about 50% vs. 30%) in the case of hemp and teff samples. In terms of the SRC profile, the qualitatively better sample M was weakened by hemp flour additions, while somewhat worse sample M1 was improved by teff flour additions. Results from the baking test showed that the hemp composites were partly dependent on hemp flour form. Volumes of bread with bright hemp were diminished from 257 mL/100g up to 196 mL/100g, the products containing dark hemp increased up to 328 mL/100g. Teff-fortified bun volumes were evaluated in close range of 325 - 369 mL/100g against 381 mL/100g for standard M1. Sensorial score of wheat/hemp breads were worse owing to spicy taste and fatty aftertaste, while hay-like by-taste in wheat/teff bread could be tolerable of 10% in recipe.

Bread and crumb features were used to compare differences between winter wheat varieties and commercial retail flours (crop years 2002–2005 and 2004–2006, respectively). Further, two commercial flours (crops 2006 and 2007) were fortified by 8 non-traditional cereals at 10% substitute level. Overall baking quality was described by bread specific volume and shape, and a crumb penetration. Image analysis software Lucia G was used for objective crumb porosity evaluation. Determination of the bread and crumb features interactions was done by correlation analysis. Baking quality of varieties was higher in crops 2002–2003 than 2004–2005 – bread volumes were 348 and 365 cm3 100 g−1 vs. 323 and 295 cm3 100 g−1, respectively. Technological quality of commercial wheat was the highest in crop 2006 and the worst within year 2004 (bread volumes 353 and 332 cm3 100 g−1, crumb penetration 21.3 and 15.7 mm). In both sample groups, crops 2004 and 2005 affected wheat baking quality similarly (e.g. in 2005, mean cell areas 1.564 and 1.338 mm2 for wheat varieties and commercial samples, respectively). Fortified bread quality profile was affected more by archaic wheat species substitution than by barley and millet. Bread cut area was correlated with 5 of 8 observed traits, among others also with specific bread volume and crumb penetration.

The analysis of the wheat hardness relation to other quality features was done with a set of 281 variety and commercial wheat samples, planted during the years of 2003-2006 in Central Bohemia and south Moravia areas. Technological quality was evaluated for grain, milling process, and flour analytics with the standard laboratory methods. The grain hardness was measured using NIR spectrophotometer Inframatic 8600. Tukey's test (ANOVA) of the grain hardness was performed for comparison between the means of wheat variety, wheat origin, crop year, growing locality, and farming intensity. As expected, the grain hardness of wheat varieties belonging to different quality classes was independent of either their classification or winter/spring type. Between all four locality means, the grain hardness among 281 samples differed insignificantly, while in the crops of 2004 and 2006 a provable increase of the kernel compactness was observed. The correlation analysis confirmed a role of the grain hardness in the milling quality assessment because of the proved correlation with 11 grain and milling quality features from the 12 tested. The strongest relation was calculated with the grain ash content, semolina yield, and flour protein content (-0.55, 0.52, 0.42, respectively).

Svec I., Hruskova M., Vitova M., Sekerova H. (2008): Colour evaluation of different pasta samples . Czech J. Food Sci., 26: 421-427. The colour of the laboratory prepared pasta was evaluated with respect to wheat flour types (M1 bright, M2 semi- bright, and M3 semolina), egg-ratio (0, 1, 2), and non-traditional cereals (archaic wheat species, tritordeum, spring barley, millet, lupin, buckwheat, and soya) supplements. The flour colour measurement confirmed its dependence on the wheat species milled − M3 obtained from durum wheat had a lower whiteness L* (89.6) and a higher yellowness b* (22.2) than the flour from common wheat (e.g. 93.6 and 8.1 for M1, respectively). As presumed, with the rising egg-ratio pasta yellowness increased − for M1-pasta, the calculated colour differences ∆ e in pairs one-egg/eggless and two-egg/eggless were 1.1 and 4.7, respectively, while for M2- and M3-pasta ∆ e values were only 0.8 and 1.5, respectively. The colour impacts of non-traditional cereals as 10% supplements differed between archaic wheat spe - cies, tritordeum, barley, and alternative cereals (millet, lupin, roasted buckwheat). In comparison to the standard, the greatest positive colour gain was brought by the lupin fortification (130% yellowness increase), while the worst appesred roasted buckwheat (10% decrease of whiteness, 210% increase of redness). At 20% non-traditional cereals supplements compared for M2- and M3-pasta, the highest positive increase of the pasta colour sensory perception was caused by corn and lupin additions in both pasta samples. The increase was slightly higher with M1-pasta (175%) than with M3-pasta (170%). In the mean of both pasta samples, yellowness L* increased from the standard pasta value 13.6 to 24.0 as measured for corn and lupin fortified pasta.

The effects of wheat cultivar and harvest year on the wheat technological quality were studied by univariate and multivariate statistical methods. Two wheat varieties sown in the harvest years 2003-2005 were used, the first one of European (cultivar Bezostaja, RUS), the second one of American origin (cultivar Jagger, USA). The evaluated parameter values indicated otherness of technological quality of the varieties studied, mostly in the milling effectivity and in proteins contents and quality. Principal component analysis (PCA) results suggested these differences, but their verifiability based on ANOVA testing was not proved. The harvest year mostly affected also the milling quality and alveograph parameters. The baking test results were not affected by either of both effects studied. The crop of 2003 had higher proximity to the crop of 2004 than to that of 2005. Multivariate analysis (cluster analysis; CA), was used to evaluate the interaction between the wheat cultivar and harvest year effects. In comparison of these effects rate, the technological quality of American cultivar Jagger was strongly influenced by the cultivar (with exception of Falling Number and gases volume). In contrast, the quality of the European wheat cultivar Bezostaja depended significantly on the harvest year.

Bakery characteristics of wheat dough and the final product and their predictability by NIR technique was investigated using 231 variety and commercial wheat samples (crop years 2003-2005). The behaviour of doughs was assessed with Brabender maturograph and OTG (Germany), the final product quality was evaluated by the baking test and image analysis. NIR spectra of flours were acquired on a NIRSystem 6500 spectrometer. Calibration equations for the selected rheological characteristics were computed by WINISI II using mPLS regression. The quality of prediction was evaluated by means of coefficients of correlation between measured and predicted values from cross and independent validation. A statistically significant dependence (with probability higher than 99%) was found with all rheological characteristics. The standard errors of cross-validation were achieved as follows: dough elasticity 16 BU, bread volume (11 min) 58 BU, specific loaf volume 34 cm 3 /100 g, bread cut area 2.6 cm 2 , penetration 4.1 mm, average cell area 0.4 mm 2 and cells per cm 2 7.4.

The milling and baking parameters of flours from foreign and Czech varieties were determined and related to milling and baking performance by correlation analysis. Twenty samples of wheat from the international breeding test CIMMYT (harvest year 2003) were used. Standard milling test at CD1 auto mill confirmed expressive different milling parameters of single varieties. Rheological properties of flours in dough were assessed at farinograph, extensigraph, fermentograph SJA, maturograph and oven spring apparatus. Baking test was also performed. Significant correlation was obtained between the milling parameters, grain hardness, flour water absorption and specific bread volume. The significant correlation was found between water absorption and yield of semolina (r = 0.79); fermentograph gases volume and yield of semolina (r = 0.89), farinograph water absorption (r = 0.77), kernel hardness (r = 0.76); specific bread volume and flour protein content (r = 0.57), the yield of semolina (r = 0.57). The most related section correlation was found between maturograph dough resistance and final dough volume on fermentograph (r = 0.70).

Fermentograph and baking properties of 98 wheat flour samples (two sets of commercial and one set of variety) were evaluated in the form of fermented dough. Analytical traits (ash and protein contents, wet gluten, FallingNumber, Zeleny sedimentation value), fermentograph parameters (gases volume, the volume of dough and the time of its max. increase), and the laboratory baking test were used for the characterisation of flours and doughs. Differences found between the two commercial flour sets were small and were influenced by the year of harvest. Significant differences were found between commercial and variety flours both in the fermentograph behaviour and in the baking test results. Lower dough volumes and lower bread specific volumes for variety flours in comparison with commercial ones were caused by a worse quality of proteins. Statistical analysis on significance level 99% showed correlations between the gases volume and the dough volume (r = 0.5264), between the gases volume and the time of dough maximum (r = -0.7689), and between the dough volume and the specific volume of bread (r = 0.5452).

The bread-making quality of forty three wheat flour samples, divided into two groups according to the ash content (up to 0.6% and 0.7%), and its changes by fortification with malt flour were studied in the form of fermented dough. Standard analytical measurements (ash and protein contents, wet gluten, falling number, Zeleny sedimentation value), rheological investigations (amylograph, maturograph, oven rise recorder), and laboratory baking test were used for the characterisation of flour and dough. The influence of the malt flour addition on the fermented dough behaviour depends on the flour composition and was found more significant in flours with a lower ash content ("bright" type). Amylograph characteristics of flour-water suspensions were affected in the same extent by the malt addition. Maturograph behaviour changed significantly only in proofing stability (without influence by the flour type) and dough firmness was affected by malt only in the case of flours with lower ash contents. Oven rise characteristics of dough and the specific bread volume showed important changes in both sets of samples with significant differences between flours with lower and higher ash contents. A strong correlation (r = 0.62-0.75) significant at 0.01 level exists between the specific bread volume and all oven rise parameters of dough from both sets of samples.

Summary Addition of non-traditional raw-materials and flours into wheat flour follows contemporary trend of manufacturing nutritionally healthier fermented bakery products. Aim of the study follows this tendency, evaluating nutritional improvement of composite flour and baking potential of prepared wheat-hemp flour composites. Hemp products addition significantly increased both protein and dietary fibre contents. Between five types of hemp flour, differences were observed according to incorporated amount (wheat flour substitution from 5% to 20%). In composites containing 20% of hemp flour and dehulled hemp wholemeal, protein content increased to 14.9% and to 15.7%, respectively (compared to 12.5% proteins in control wheat flour). Dietary fibre content change was governed unequivocally by addition level for both hemp flour and hemp wholemeal. Hemp wholemeal affected the solvent retention capacity (SRC) profile of the wheat flour used in a broader extent than hemp flour done, interacting moreover with addition level applied. Significant diminishing was measured for the sucrose and the lactic acid SRC, which describe physicochemical stage of starch and proteins in prepared composites. Addition of 5% and 20% of dehulled hemp wholemeal decreased the formed SRC from 112.0% to 102.3% and to 64.1%, and the latter SRC from 182.6% to 108.0 and to 78.3%, respectively. Smaller bread volume and worse shape were evaluated as the amount of hemp flour gradually increased; wholemeal form had more or less a positive effect. Correspondingly to that, crumb firmness measured by penetration test was found approximately half for hemp flour composite bread than for the hemp wholemeal ones.

The mixolab, a rheological device developed recently, combines approved farinograph and amylograph test procedures. Analysing wheat flour composites with hemp, teff, or chia in terms of all three mentioned rheological methods, correspondence of farinograph, and amylograph versus mixolab features was examined by principal component analysis. The first two principal components, PC1 and PC2, explained 75% of data scatter and allowed a satisfying confirmation of presumed relationships between farinograph or amylograph and mixolab parameters. Dough development time and stability were associated with gluten strength (C1 torque point) and also dough softening (mixing tolerance index) had a link to protein weakening (C1-C2 difference). In the second mentioned case, amylograph viscosity maximum and amylase activity (C3-C4) closeness was verified. Starch and starch gel properties during mixing (C3, C3-C2, and C4) affect dough viscosity (C1) and rheological behaviour (dough development time and stability). Another important finding is unequivocal distinguishing of the composite subsets (of hemp, teff, and chia ones) by the used rheological methods and statistical treatment of multivariable data.

Chia flour from white and brown seeds were tested in dry and hydrated form. In flour composites, ash and protein content was verifiably increased by both chia types (up to about 2%). Non-starch polysaccharides content also increased, as the sucrose SRC confirmed. Protein technological quality was affected by alternative plant materials, measured as Zeleny value diminishing. Water suspension viscosity and dough elasticity increased during amylograph and extensigraph tests. For composites including hydrated chia form, somewhat higher elasticity was determined; the change was positively reflected in baking test results (bread volume increased about 20% at least). Bread crumb morphology changed gradually, determined by deeper penetration rate. Higher elasticity of dough containing hydrated chia form limited small pores coalescence into larger ones, resulting into firmer crumb compared to bread with dry chia flour. That was verified by soft diminishing of mean pores area and reversely by increase in pores density within order of samples wheat bread – dry chia flour bread – hydrated chia flour bread. Pore sizes distribution was varied, too – by chia flour, counts of small and large pores (area smaller than 1.5 mm2 and larger than 4.2 mm2, respectively) were magnified approximately twice and lowered to ca half, respectively.

Hruskova M., Svec I., Sekerova H. (2011): Colour analysis and discrimination of laboratory prepared pasta by means of spectroscopic methods. Czech J. Food Sci., 29: 346–353. For the CIE Lab colour profile determination of laboratory prepared pasta, two sample granulations and two spectral methods were tested. Pasta was manufactured progressively from semolina, common wheat, and corn flour. Sufficient colour spectra ranges were ensured by means of fortification with 9 non-traditional cereals in the first case, 8 natural colorants in the second one, and with 12 gluten-free pasta recipes in the last case. Both factors (i.e. granulation and spectral method) were proved as statistically significant by the cluster, variance and principal component analyses. In the comparison of the effects on the pasta composition and the spectral method, the latter demonstrated a stronger impact on the pasta colour profile measured.

Wheat flour was fortified by 2.5, 5.0 or 10 wt. per cent of linseed fibre, gained from seeds of golden flax varieties Amon and Raciol and brown one Recital (granulation 500 - 700 m), prepared from 2015 and 2016 harvests. Using analytical tests, namely sedimentation according to Zeleny and Falling Number, basic technological quality of flour composites was mostly independent on all three observed factors (harvest year, linseed variety and addition). Rheological tests included the farinograph, the extensigraph and the amylograph proofs. Enhancement by brown and yellow flax fibre significantly contributed to rise of farinograph water absorption and to dough stability shortening, directed mainly by addition level. Extensigraph curves course depended on dough resting time, higher differences between wheat control and flour composites were observed after 60 min dough resting. Linseed fibre weakened dough extensibility, and energy as area under curve also partially decreased about 3, 8 and 25% in average as portion of alternative materials in dough has risen. Compared to control, suspension viscosities of tested flour composite generally increased; the strongest effect was recorded for composite samples from harvest year 2016. During dough leavening, tested samples were differentiated according to maturograph dough resistance, and interaction of all three factors was identified. Regardless to variantion in dough machinability, specific volumes of composite bread samples were similar through whole sample set - any unequivocal trend was found. Somewhat worse vaulting of bread was calculated for buns manufactured from raw materials of 2016 harvest. Reversely, linseed fibre produced in 2015 improved crumb softness, especially at 5% enhancement (about ca 50% in average). The lowest addition of linseed fibre resctricted biscuits spread during baking in the highest extent, but rising level of enhancement suppressed elevated dough elasticity. Both cereal products were considered as acceptable for common consumers. Multivariate PCA method verified changes mainly in protein visco-elastic properties, which were reflected in bread and biscuits quality in an opposite manner. Based on this statistics, quality of wheat controls was comparable in both harvest year if related to changes induced by linssed fibre. In opposite to this, technological and consumer's parameters of flour composites and manufactured cereal products were statistically dependent of harvest year of linseed. As presumed, the lowest addition level brough the smallest changes; multiplied fortification caused gradual variation in results of all conducted proofs. Owing to high dietary fibre content in linseed fibre (over 50%), the medium dosage of the alternative material (i.e. 5% addition) could be recommended for praxis.

Bread and bread crumb characteristics as the results of laboratory baking test were used to assess bread profile. Its texture was quantified by image analysis technique, performed by using the Kaiser reproset (stand, lighting), the COHU CCD camera and the NIS Elements 2.0 AR software. In the case of common cereals fortification (wheat, rye, barley, oat and corn wholemeal flours), tested substitution level were chosen from 10% to 50% of commercial wheat flour standard “M’09”. Its analytical parameters correspond with satisfying bakery quality (protein content 14.1%, Zeleny's value 36 ml, Falling Number 396 s). Non-fortified bread from M’09 reached specific volume of 365 mL/100 g, and bread texture was described by 14 cell/cm2 and mean cell area (MCA) 2.538 mm2. The second fortification attempt included four non-traditional wheat (spelt, dicoccum, spring wheat ‘Trinaldina’, one with purple grain) and millet. These recipe components were tested on two commercial wheat samples, marked as “M’06” and “M’07”. Their baking values differed in protein content only (12.3% vs. 11.5%, respectively), while the Zeleny's sedimentation and the Falling Number test results were comparable (49 ml vs. 49 ml and 324 s vs. 363 s, respectively. Lower protein content as well as higher Falling Number contributed to lower bread volume from M’07 flour (252 mL/100 g vs. 343 mL/100 g), and also its texture was less open (20 cells/cm2 at mean cell area 1.160 mm2 against 15 cells/cm2 at 1.520 mm2). Statistical approach comprised correlation and variation analyses (Tukey's test) on significance level of 95% for both methods. Addition of common cereals wholemeal caused progressive changes of both specific bread volumes and crumb morphology, i.e. volume of bread with 10% and 50% of rye wholemeal fell from z 235 mL/100 g up to 155 mL/100 g. An extraordinary position was revealed out for wheat wholemeal, which did not affect dough volume rise at baking stage due to similar protein structure (specific values of 233 mL/100 g a 259 mL/100 g, respectively). Cell densities were 21 cells/cm2 and 25 cells/cm2 for recipes with 10% and 50% of rye, respectively. Corresponding MCA's were evaluated on levels of 1.617 mm2 and 1,365 mm2, respectively. Compared to standard M’09, a decrease about 25% was registered. Influence of wheat wholemeal was equivocal likewise the specific bread volume – numbers of cell in bread crumb with 10% and 50% of that component were 18 per cm2 for both cases, whereas the proper MCA's were 1.830 mm2 in the former and 2.128 mm2 in the latter case (72% and 83% of standard M’09). Texture of the selected samples is documented on Fig. 1. Bread prepared from “M’07” was affected differently due to lower baking quality – crumb texture changes oscillated up to 20%. Figure 2 shows major influence for bread with TSP (77% increase in mean cell area, 23% decrease in number of cells/cm2). The most levelled change in these two bread crumb parameters was observed for bread with WPG – mean cell area increased about 20%, while number of cells/cm2 decreased about 23%.

In wheat and flour processing many traits have to be investigated for quality control. However, conventional methods available for technological quality assessment of wheat grain and flour are generally tedious and/or requiring expensive equipment. To overcome these drawbacks in common use, alternative methods using spectroscopy have been developed. The objective of this study was to utilize near-infrared reflectance spectroscopy (NIR) to analysis of milling and baking parameters: flour extraction, protein content, Zeleny sedimentation, deformation energy, gas volume and baking volume. Samples including Czech and international varieties were collected from a field experiments (crop years 2002–2005) and laboratory milled on Chopin CD1. Spectra were acquired on a scanning monochromator NIRSystems 6500 in the range from 400 to 2500 nm. Calibration equations were obtained both with classical and modified partial least square (PLS) regression analysis of conventional laboratory analysis values on 168 selected NIR spectra using WinISI computer software. Those were externally validated with additional samples from commercial wheats. Prediction of flour extraction, Zeleny sedimentation and protein content in particular gave a very good accuracy. The results indicate that NIRS can also determine some rheological traits (deformation energy, gas volume and specific loaf volume) at least with a screening performance.