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Three non-food cultivars of winter wheat (Biscay, Clarus, Rapsodia) were grown at four locations in the Czech Re public with different agro-ecological conditions in the years 2005–2008 and two levels of nitrogen fertilization – 90 and 120 kg N/ha were used. The influence of growing conditions (year, location, cultivation technology) on grain yield, starch content, protein, gluten, share of amylose in starch, falling number and amylographic characteristics. All qualitative indicators were significantly affected by the weather. Wheat grown in the areas 500 m a.s.l. had lower grain yield of 2.8 t/ha (8.4 t/ha), higher starch content of 2.1% (69.0%) and lower content of proteins by 1.8% (10.2%) in grain than wheat grown in the fertile conditions (below 300 m a.s.l.). The cv. Biscay had the highest starch content of 68%; the proportion of amylose in the starch was in the range 22–27%. The content of proteins was negatively correlated with starch content (r = –0.89). The level of damage of starch α-amylase was most affected by wet weather during ripening – falling number was 62 s, with a very low amylographic gelatinization maximum (30–155 Brabender units) and a low gelatinization temperature at the maximum (67–74°C). The respective values recorded in dry conditions were ca 300 s, AU 600 and 90°C. Most damaged starch was recorded in the cv. Clarus.

Codina G.G., Mironeasa S., Bordei D., Leahu A. (2010): Mixolab versus Alveograph and Falling Number. Czech J. Food Sci., 28: 185-191. Recently, in 2005, a new method for monitoring the rheological properties of the dough on the entire technological process of bread making became available through Mixolab at an international level. This laboratory equipment has amazing possibilities for the research and development, enabling a complex analysis of flour. It allows the analysis of flour proteins quality (water absorption, stability, elasticity, weakening), the analysis of starch behaviour (gelatinisation, gelatinisation temperature, the modification of its consistency on additives addition) and the analysis of enzymatic activities (proteolytic, amylolytic). The objective of this study is to establish a relation between the alveograph, Falling Number, and Mixolab values. Sixty flours, collected around the Romanian country, were analysed simultaneously on alveograph (standard protocol), for the Falling Number, and on Mixolab ("Simulator" and the standard option "Cho - pin+" protocol). A selection of principal factors based on the Principal Component Analysis (PCA) was applied which allowed the building of an efficient predictive model for each parameter. There were significant correlations between most of the Alveograph parameters: maximum pressure (P), deformation energy (W), extensibility (L), alveograph ratio (P/L) and Simulator Mixolab stability. Using the Mixolab standard option "Chopin+" protocol a close association was found between some Mixolab parameters: stability and protein weakening (C2, difference of the points C1-C2 abbreviated C12) and the alveograph values (P, W). From the point of view of the correlations established with the Falling Number index, very good results were obtained with the parameters obtained with Mixolab that measures starch gelatinisation (C3, difference of the points C3-C2 abbreviated C32), amylolytic activity (C4, difference of the points C3-C4 abbreviated C34), and starch gelling (C5, difference of the points C5-C4 abbreviated C54).

Four year trials were undertaken to study the milling and baking rye quality, the hybrid variety Picasso and population varieties Dankowskie nowe and Selgo having been examined coming from three different locations of the Czech Republic. The variety significantly (P < 0.01) influenced the specific weight, grain size, amylograph maximum, and grain yield. The year of harvest significantly (P < 0.01) influenced the thousand grain weight, maltose content, protein content, amylograph maximum, and grain yield. The location significantly (P < 0.01) influenced the thousand grain weight, protein content, amylograph maximum, and grain yield. The highest pentosan content (average of the four years and three locations) was achieved by the hybrid variety Picasso (8.04%), which had the highest Falling number (232 s) as well as amylograph maximum (597 AU). The location Hradec nad Svitavou proved to be the best (8.02% pentosans) while the year 2005 (8.34% pentosans) was the most positive. A positive correlation (P < 0.05) was found between the pentosan content and the Falling number.

This work presents the results of a survey that studied simulated plant browsing by herbivores. In 2004–2006, win ter wheat, spring barley, and maize field trials were founded in order to monitor the impact of different levels of defoliation (leaf area reduction) on the yield and grain quality. The defoliation was carried out by means of mechanical removal of plant parts in the early growth stages. Selected qualitative parameters were determined in the harvested grain of wheat and barley. Statistically significant influence of leaf area reduction (LAR) on grain yield (decrease by 4–14%) was found only in maize in 2004. No statistically significant influence of the leaf area reduction on thousand grain weight (TGW) was found in any of the studied crops. The leaf area reduction in barley did not affect grain characteristics; however, it had a statistically significant influence on the quality of wheat grain. Moreover, wheat reduction statistically significantly increased the falling number (by 29–39 s) and decreased SDS test values (by 8–9 ml).

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.

Technological quality of wheat from 2001 and 2002 harvests and its changes in the course of one-year storage were evaluated using protein content, SDS and Zeleny tests and falling number. Average values from the analyses of ten partial samples that were taken from five Central Bohemian producers (beet-producing region) during the period of eleven months (from October to August) characterise wheat standard quality for the mill processing and it is possible to explain their variations by the effect of the harvest year in the comparable wheat variety composition. With regard to similar climatic conditions of the years 2001 and 2002, there were not found any marked differences in protein content (2001 - average 12.4%, 2002 - average 12.8%) and Zeleny test (2001 - average 52 ml, 2002 - average 55 ml) but the falling number was significantly different (2001 - average 321 s, 2002 - average 287 s). During the storage time in agricultural operations no conclusive changes in protein content were found though protein quality slightly decreased according to the SDS and Zeleny test values. Falling number values of wheat from 2001 harvest slightly increased, which was not evidential for the set of samples from 2002. Statistically significant correlations were calculated between the falling number value of wheat and its laboratory-manufactured flour in both harvest years (r = 0.556 in 2001, r = 0.825 in 2002). The value of Zeleny test significantly correlates with SDS test (r = 0.531 in 2001, r = 0.787 in 2002) as well as with protein content.

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.

HRUSKOVA M., MACHOVA D. (2002): Changes of wheat flour properties during short term storage. Czech J. Food Sci., 20: 125–130. Two samples of commercial wheat flour from the last year’s harvest were stored for three months (in the period from November to April) under different conditions. The ambient temperature and humidity varied during the storage in the dependence on the year season. Certain analytical characteristics (moisture, wet gluten and its extensibility, acidity and falling number) and al veograph behaviour of flour were determined at regular intervals. Flour moisture, acidity, and falling number changed with the time of storage but no explicit influence of the storehouse conditions and the initial flour properties was proved. Viscoelastic proper ties of weaker flour samples changed during storage more markedly than those of stronger flours in the sense of a significant improvement of their quality.

The effect of microwave (MW) heating on the changes in wet gluten content, Gluten Index, Falling Number and amylographic characteristics was studied in sprouted wheat grain. Different moistures of wheat in two ranges of 10-11% and 15-17% and two end temperatures of MW heated samples (60 and 80°C) were applied to wheat samples. Falling Number and Gluten Index increased with increasing absorbed energy during MW heating, whereas gluten content decreased. Amylographic maximum increased due to α-amylase inactivation progressively with increasing absorbed energy as well. The greatest relative changes occurred when the end temperature of MW heated samples 80°C and moisture 15% were used. An improvement effect on the baking quality of sprouted wheat was found due to an increase in amylographic maximum with higher energy doses and higher end temperatures of MW heated samples. It was a consequence of Falling Number increase and Gluten Index increase with lower energy doses. The negative effect of higher energy doses was proved in a decrease in wet gluten content.