How Arabinoxylans Modify Gluten and Starch Related Wheat Flour Characteristics

The positive nutritional impact of dietary fibres (DF) gives growing interest to their role in the formation of wheat product quality. Although we are getting closer to characterize the effect of DF on the end use quality, the roles of individual components are not well described yet. Arabinoxylans (AX) are the main compounds of wheat DF, therefore getting more knowledge about its behaviour in wheat based food systems, like dough or end products, could be useful from both theoretical and practical points of view. The aim of this study was to investigate the impact of the AX content on wheat flour quality using a dough model system provided by blends of flour and AX isolate. Rapid Visco Analyser (RVA) and recently developed micro Zeleny test were used for characterization of mixtures. We found that although Zeleny values are basically related to protein-dependent quality, the addition of AX isolate has major impact on the sedimentation volume of flour. In the RVA studies we demonstrated that AX has influence not only on the viscosity values but also on the rate of viscosity change. The effect of AX addition was compared to that of starch addition and was corrected by the rate of dilution. The model system and the experimental method applied here can be suitable to separate the individual effects of non-starchy carbohydrates

Changing of carbohydrates by inoculation of Pseudomonas savastanoi pv. phaseolicola oil bean lines with different resistance

The Pseudomonas savastanoi pv. phaseolicola (PS) is one of the most significant stressors of bean (Phaseolus vulgaris L.). Chemical and agrotechnical treatments have minor importance, so breeding has great part in the protection against this pathogen. Most of the cultivars are susceptible to PS. The genetic background of resistance in the plant is a complex system. Leaf resistance is a monogenic system, but there are some modifier genes. The pathogen species can be divided into different races. To understand the functioning of this resistance gene, experiments were carried out using bean varieties with different genotypes and near isogenic lines of bean. Eight lines were tested. Our main objective was to test bean lines with PS with high virulence. The experiment was made in greenhouse and on field. The virulent bacterium strain has been isolated in Hungary. The changes of carbohydrates were tested after infection. In homeostasis the level of carbohydrates (especially glucose and fructose) were higher in susceptible lines. In case of artificial and natural infection the decrease of glucose were more significant in susceptible lines than in resistant lines. In the leaf samples from systemic chlorosis the level of this carbohydrate increased. These changes are connected with the level of resistance, but more experiments are needed to verify this assumption

Changing of carbohydrates by inoculation of Pseudomonas savastanoi pv. phaseolicola oil bean lines with different resistance

The Pseudomonas savastanoi pv. phaseolicola (PS) is one of the most significant stressors of bean (Phaseolus vulgaris L.). Chemical and agrotechnical treatments have minor importance, so breeding has great part in the protection against this pathogen. Most of the cultivars are susceptible to PS. The genetic background of resistance in the plant is a complex system. Leaf resistance is a monogenic system, but there are some modifier genes. The pathogen species can be divided into different races. To understand the functioning of this resistance gene, experiments were carried out using bean varieties with different genotypes and near isogenic lines of bean. Eight lines were tested. Our main objective was to test bean lines with PS with high virulence. The experiment was made in greenhouse and on field. The virulent bacterium strain has been isolated in Hungary. The changes of carbohydrates were tested after infection. In homeostasis the level of carbohydrates (especially glucose and fructose) were higher in susceptible lines. In case of artificial and natural infection the decrease of glucose were more significant in susceptible lines than in resistant lines. In the leaf samples from systemic chlorosis the level of this carbohydrate increased. These changes are connected with the level of resistance, but more experiments are needed to verify this assumption