Authors:D. Fekete, G. Balázs, V. Bőhm, E. Várvölgyi, and N. Kappel
The objective of our study was to analyse the results of two measuring methods (sensory evaluation and electronic tongue) and to find differences in taste between grafted and non-grafted watermelon fruit. The trained sensory panel evaluated in two years three differently treated watermelon fruit. The studied fruit samples were produced on the same growing-areas in both years but with different growing technologies. The experiment used the non-grafted/self-rooted watermelon as control sample, while the other two treatments were grafting on two rootstock types: a Lagenaria and an interspecific squash hybrid rootstock. The electronic tongue measurement showed that it is the environment/growing technology that mainly determines the characteristics of the fruit quality, not grafting. The two measurement methods can complement each other in a detailed and practical way, as technology and growing area strongly influence the quality of watermelon fruit. The research also showed that it is possible to have similar watermelon fruit quality, independently from the used rootstock type.
Authors:K. Török, L. Hajas, Zs. Bugyi, G. Balázs, and S. Tömösközi
Disorders induced by cereal proteins (e.g. wheat allergy, celiac disease) are widespread in human population. Since their only effective treatment is the avoidance of the problematic proteins, patients have to be familiar with the composition of food products. For checking special foods produced for them, proper analytical methods are necessary. At the moment, in gluten analysis there are no reference methods and reference materials which model real food matrices. During the production and experimental utilisation of our previously developed reference material candidate, numerous questions emerged. As our model product is a real food matrix, interactions can be present between gluten proteins and other macro and micro components. Fat content of the baked cookies is almost 20%, which might affect the results of ELISA measurements. The detectable gluten content is significantly increasing after the defatting procedure, as a pre-treatment of samples. Moreover, baking is a common food processing step that might modify the structure of gluten proteins leading to denaturation and aggregation. In the soluble protein fraction the amount of low molecular weight proteins increases, while that of high molecular weight proteins decreases during the baking procedure.
Authors:G. Jenser, Klára Balázs, V. Markó, and A. Haltrich
About 2500 arthropod species
immigrate, or carried by wind, or introduced by man in the orchards, under
Hungarian climatic conditions. However, the number of the apple pest species is
approximately 30. Owing to the effect of the relationships among the plant-phytophagous-zoophagous species those could
colonize the orchard for which the apple provides suitable food sources and
whose populations are not regulated or are regulated by a weak efficiency by
parasitoids and predators. These populations create the primary pest
communities. When the individual number of the parasitoid and predator species
is reduced by the broad-spectrum insecticides, the population density of those
phytophagous species could increase whose populations was restricted up to that
time. In this case the secondary pest communities could develop. The integrated
pest management provides the possibilities to solve the problems caused by the
regular use of broad-spectrum insecticides. The real requirement is to find and
to harmonize those methods which regulate the population dynamics of the
species of the primary pest communities.
Authors:M. Rakszegi, G. Balázs, F. Békés, A. Harasztos, A. Kovács, L. Láng, Z. Bedő, and S. Tömösközi
Damaged starch, protein and arabinoxylan (AX) content and composition have been related to water absorption (WA) in a large set of samples. We tested 20 modern bread wheat cultivars bred in Hungary, 20 old Hungarian landraces, and 17 cultivars with special biochemical/functional characteristics from all around the world, this last set for international comparison. Grain was field grown in the 2011 and 2012 harvest seasons. Alinear mathematical model has been developed to estimate WA from protein content, starch damage, AX content and the relative amount of soluble proteins with strong correlation (r2 = 0.65) between measured and estimated data. The introduction of a new parameter, related to the cultivar dependent quantitative composition of soluble proteins and determined by lab-on-a-chip (LOC) analysis, largely improved the predictability of WA. Based on the large variation among the level of AX and certain soluble protein components in wheat flour and their significant contribution toWA determination, it was concluded, that these properties could be appropriate target traits to alter them during wheat breeding programs to improve the WA of wheat flour.
Authors:G. Balázs, I. Baracskai, M. Nádosi, A. Harasztos, F. Békés, and S. Tömösközi
The utilisation of microchip capillary electrophoresis has the potential to improve the capability of high throughput sample analysis of biomolecules. The aim of this study was to review this capability for cereal protein analysis.The commercially available lab-on-a-chip (LOC) technology was characterised in the separation of total proteins extracted from whole wheat meals. Important analytical parameters (such as repeatability) of both qualitative (molecular size estimation) and quantitative (relative percentage of total protein) aspects of LOC data were determined and discussed in the light of the need of possible applications. It revealed that the LOC has very good repeatability and reproducibility parameters; however the non-globular structure of the proteins can highly affect the sizing accuracy. Among other applications, the profiles were found to be suitable for wheat cultivar identification and to monitor environment related alterations on protein composition.After a confirmation process the LOC can be an appropriate tool for fast protein profile screening in cereal science and technology in diverse applications, and it can complement the conventional methods of analysis.
Authors:A. Harasztos, G. Balázs, P.N. Csőke, S. D’Amico, R. Schönlechner, and S. Tömösközi
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.
Authors:A. Bagdi, G. Balázs, J. Schmidt, M. Szatmári, R. Schoenlechner, E. Berghofer, and S. Tömösközia
Six varieties of proso millet (Panicum miliaceum L.) and two commercially available millets were investigated in the present study. In order to explore the nutritional potential, major nutrient composition, mineral composition, antioxidant capacity, total phenols content (related to the antioxidant capacity) and dietary fibre content were determined. The effects of decortication on these components were examined. In addition, protein profile of the varieties and amylose/amylopectin ratio of the starch were examined. The range of the values measured for major nutrient composition corresponds with data of other millet species published in earlier studies. Remarkable differences were found among the protein contents of the varieties (11.58–14.80%). Although the concentration of minerals was low in the varieties examined, in comparison with other cereals wholegrain millet seems to be nutritionally valuable because of their high dietary fibre content. Decortication had no effect on the protein and fat content of millets, however, it significantly decreased the content of crude fibre, dietary fibre, minerals, total phenols content and antioxidant capacity. Consequently the applicability of millets as functional food decreases. Decortication had no effect on the amylose/amylopectin ratio of millet. No varietal differences were found in terms of protein characteristics.