For a number of applications, gluten protein polymer structures are of the highest importance in determining end‐use properties. The present article focuses on gluten protein structures in the wheat grain, genotype‐ and environment‐related changes, protein structures in various applications, and their impact on quality. Protein structures in mature wheat grain or flour are strongly related to end‐use properties, although influenced by genetic and environment interactions. Nitrogen availability during wheat development and genetically determined plant development rhythm are the most important parameters determining the gluten protein polymer structure, although temperature during plant development interacts with the impact of the mentioned parameters. Glutenin subunits are the main proteins incorporated in the gluten protein polymer in extracted wheat flour. During dough mixing, gliadins are also incorporated through disulfide‐sulfhydryl exchange reactions. Gluten protein polymer size and complexity in the mature grain and changes during dough formation are important for breadmaking quality. When using the gluten proteins to produce plastics, additional proteins are incorporated in the polymer through disulfide‐sulfhydryl exchange, sulfhydryl oxidation, β‐eliminations with lanthionine formation, and isopeptide formation. In promising materials, the protein polymer structure is changed toward β‐sheet structures of both intermolecular and extended type and a hexagonal close‐packed structure is found. Increased understanding of gluten protein polymer structures is extremely important to improve functionality and end‐use quality of wheat‐ and gluten‐based products.

No abstract

Length of GMP, especially in relation to length until maturity, governs gluten strength (%UPP) and grain protein concentration (TOTE). Length of GMP is determined by cultivar, temperature during GMP and late nitrogen availability.

Fertilizer application and growing locations are known to influence yield and protein concentration of malting barley. The aim of the present investigation was to evaluate the influence of soil and starter fertilizer on yield and protein composition in mature and maltedbarley. The cultivar Prestige was grown in two different soils (Lunnarp and LaxmansÅkarp) in combination with the use/non-use of starter fertilizer in climate chambers. Yield parameters, protein concentration and composition was measured. Effect of soil on plant emergence, yield and protein composition was significant while the effect of starter fertilizer was not. More nitrogen rich and low humus content soil (Lunnarp) resulted in higher grain yield and polymerization of proteins and lower protein concentration than the other soil. Combination of soil and starter fertilizer influenced protein composition in mature and malted barley. Breakdown of proteins were significantly higher at certain combination of soil and starter fertilizer than with other combinations. The Lunnarp soil combined with starter fertilizer was preferable to obtain high yield, low protein concentration and large grain size in mature grains. When breakdown of proteins at malting was taken into consideration as well, Lunnarp soil together with no starter fertilizer might be the best option.

8Seed enhancement technologies i.e. priming, pelleting and coating have been extensively 9 used throughout the last century to improve crop yield and to reduce losses associated with 10 pest infestation. However, until recently, it has not been possible to non-destructively assess 11 the effect of seed enhancement technologies belowground due to the opacity of soil. Using X-12 ray Computed Tomography (X-ray CT) we undertook a 4D visualisation of the germination 13 process of four different sugar beet seed enhancement treatments (untreated / naked, coated, 14 pelleted and pelleted + coated) in soil. The aim of this study was to improve the understanding 15 of the germination process in the natural environment of the seed to inform future soil 16 management and seed enhancement processes. Using X-ray CT we were able to quantify the 17 germination and establishment process of different seed enhancement technologies in soil 18 non-destructively for the first time. We observed a delay in seedling growth posed by the 19 addition of a physical barrier, i.e. the seed coating. However, an enhanced radicle growth rate 20 was observed in pelleted, as well as pelleted and coated seeds, after overcoming the physical 21 barrier. The disadvantage posed by the addition of seed coating was overcome after four days 22 of seedling growth. Further work should focus on refinements to the type and composition of 23 the pelleting which we observed to have a retarded effect on seed germination. 24 Introduction 25