Authors:M. Oszvald, S. Tömösközi, L. Tamás, and F. Békés
Structure and composition of wheat storage proteins and functional properties of wheat gluten are well studied; therefore several methods and instruments are available to determine these properties. The investigation of functional properties of rice proteins, depending on the different goal of utilisation, has not been well established, yet. In this study, the rheological properties of four varieties of rice flour were studied using a 50 g Farinograph demonstrating the mixing properties of rice flours and the alterations of these properties caused by the supplementation of wheat proteins. The considerable differences identified on the mixing curves of different rice flours indicate that the investigation of mixing properties can be one of the useful approaches for the characterisation of functional properties of rice dough. The large effects of the addition of wheat gluten on the mixing properties of rice flours demonstrate the possibility of using rice flour and dough as a wheat protein free model system for the in vitro investigation of the functional roles of wheat storage proteins.
Authors:M. Oszvald, B. Jenes, S. Tömösközi, F. Békés, and L. Tamás
We generated and analysed transgenic rice lines synthesizing substantial amounts of high-molecular-weight glutenin subunit (HMW-GS) from wheat. Particle bombardment has been used to transform rice cultivars (
L.) with a cassette carrying the gene of 1D×5 HMW glutenin subunit. Twelve independent lines were recovered and PCR results on genomic DNS confirmed the integration of the transgene into it. Five lines set seeds. Seeds were analysed by SDS-PAGE and Western blot and we proved the presence of foreign protein in the starchy endosperm. The amount of 1D×5 HMW-GS in rice endosperm represents 0.75–3.18% of the alcohol soluble proteins. These results are the first example of significantly changing storage protein composition of rice exploiting the method of gene technology. This alteration may have considerable effect on the functional properties, including strength and stability of the dough made of transgenic rice flour.
Authors:I. Baracskai, G. Balázs, L. Liu, W. Ma, M. Oszvald, M. Newberry, S. Tömösközi, L. Láng, Z. Bedő, and F. Békés
The glutenin allele gene-pool, the distribution of the individual alleles on the 6 loci coding for glutenin subunits and their combinations were determined in a sample population containing 107 cultivars bred and grown in Martonvásár, Hungary at the Agricultural Research Institute of the Hungarian Academy of Sciences. The database is based on the results of three independent analytical procedures carried out using the traditional SDS-PAGE based allele identification, the state-of-art MALDI-TOF technology and the high throughput capillary electrophoresis based on the lab-on-a-chip technique. The usefulness of integrating the information on both HMW GS and LMW GS allelic composition for future genetic and technological improvement is discussed.