Effect of bran reduction on gluten secondary structure in intermediate Wheatgrass (Thinopyrum Intermedium) Dough

Introduction: Thinopyrum intermedium, commonly known as intermediate wheatgrass (IWG), is a perennial crop with favorable agronomic characteristics; reduces soil and water erosion, increases nitrogen fixation and disease resistance. We have previously shown that in comparison to wheat controls, IWG lines had higher protein and dietary fiber contents. However, the protein distribution is significantly different from that of hard red winter wheat (HRWW). The difference in protein distribution coupled with higher fiber content negatively affects the dough rheology in terms of protein network formation. Therefore, the objective of this study was to determine the effect of bran reduction on the gluten secondary structure in IWG dough using Fourier transform infrared (FTIR) spectroscopy. Method: IWG grains sample was milled and bran was separated. Bran was added back to refined IWG flour at 100%, 75%, 50%, 25%, and 0% of original bran content. Using Differential Scanning Calorimetry (DSC), gluten protein glass transition temperatures at various moisture contents were determined to identify optimum dough forming conditions. Different flour samples were evaluated for dough strength using farinograph following the constant flour weight procedure according to AACC method 54-21.02. Dough samples were collected at different time points during mixing: dough development time, stability departure, and overmixing. Flour and dough samples were subjected to FTIR spectroscopy to determine changes in protein secondary structure. Significance: Determining differences in gluten secondary structure as affected by bran content during dough formation provides insights to gluten network formation and stability during dough mixing and baking. This information leads to optimization of IWG grain processing and utilization in order to expand its market potential. Results: The milling of IWG grains yielded 59% for bran and 41% for refined flour, while milling of wheat control yielded 40% and 60% respectively. The glass transition temperature of extracted gluten from IWG was 37\ub0C compared to room temperature for gluten from control wheat at 16% moisture. Farinograph was carried out both at 30\ub0C and 40\ub0C for all the flour samples. Differences in secondary structure profile were noted between IWG and control wheat dough at the various mixing times

Effect of Bran Reduction on Gluten Secondary Structure in Intermediate Wheatgrass (Thinopyrum intermedium) Dough

Thinopyrum intermedium, commonly known as intermediate wheatgrass (IWG), is a perennial crop with favorable agronomic characteristics. In comparison to wheat, IWG has higher protein and dietary fiber contents. However, the protein distribution is significantly different from that of hard red winter wheat. The difference in protein distribution coupled with higher fiber content negatively affects the dough rheology in terms of protein network formation. Therefore, the goal of this study was to determine the effect of bran reduction on the gluten secondary structure in IWG dough using ATR-FTIR spectroscopy. IWG grains sample was milled and bran was separated. Bran was added back to refined IWG flour at 100%, 75%, 50%, 25% and 0% of original bran content. Different flour samples were evaluated for dough strength using farinograph following the AACC method 54-21.02 at two temperatures 30\ub0C and 21\ub0C. Dough samples were collected at different time points during mixing: dough development time (DDT), stability departure, and overmixing, and were subjected to FTIR spectroscopy to determine changes in protein secondary structure. At 30\ub0C, IWG bran reduction did not cause significant structural changes in the dough made at DDT. At 21\ub0C, inclusion of bran caused partial dehydration of gluten giving more f-sheets at the expense of f-turns. Decrease of temperature in 100% IWG dough made at DDT resulted in more beta turns contributing to weaker dough. As mixing time increased, more f-sheets were formed at the expense of f-turns in the IWG dough possibly due to mechanical disruption of gluten network and formation of protein aggregates. Determining differences in gluten secondary structure as affected by bran content provides insights into gluten network formation and stability. This information leads to optimization of IWG grain processing in order to expand its market potential

Intermediate Wheatgrass (Thinopyrum intermedium) : a 360 ° evaluation

Intermediate Wheatgrass (Thinopyrum intermedium), IWG, is a perennial grain currently being investigated for food uses. The benefits of perennial cultivation are manifold, including reduced nitrogen leaching and increased carbon sequestration. From a sustainability point of view, IWG seems like a perfect candidate for human food production, but for the food scientist, it does present certain challenges due to its composition. It does contain gliadins, and is thus not marketable as gluten-free, but it does not have the same profile or content of high-molecular weight glutenins and thus dough forming properties are poor compared to wheat. In addition, due to lower endosperm contents, the grain is lower in starch but higher in dietary fiber than more commonly cultivated grains. In recent years, researchers have investigated IWGs ability to form dough, its protein structures and interactions, as well as the effect of grain refinement on IWG dough rheology and bread-making performance. Starch gelatinization and retrogradation properties have also been investigated. Moreover, we are conducting storage studies evaluating rancidity due to autoxidation and enzymatic action, and phytochemical status. This presentation will provide an overview of the latest findings on IWG focusing on protein and starch features and their impact on final product quality. Improving the knowledge on IWG, its shelf life and its macromolecules will better define its application potential in human nutrition

Exploring the potential of perennial grain Intermediate Wheatgrass (Thinopyrum intermedium) as a novel food ingredient

Sustainable food production starts with sustainably produced ingredients. Cereals are staple foods all over the world, and all major cereals are annual plants. From an environmental perspective, the main advantage of perennials over annuals is the perennials\u2019 extended root system. Introducing perennial alternatives to annual cereal crops would open up a new way for combating problems such as soil erosion and nitrogen leaching. Among the perennial grains currently explored for food cultivation is Intermediate Wheatgrass (Thinopyrum intermedium), IWG. However, cereals need to fulfill certain functional requirements, depending on the end use. Therefore, in collaboration with breeders, geneticists and agronomists, a team of food scientists is currently characterizing IWG breeding populations for parameters relevant to food use. Cereal proteins have the biggest influence on a grains\u2019 application potential. The prolamin profile of IWG is similar to many other cereal grains: It is poor in high-molecular weight glutenins and therefore dough-forming ability, but does contain gliadins, and can therefore not be marketed as gluten free. Moreover, while breeders have succeeded in increasing endosperm to bran ratios, the grains are much thinner than more commonly cultivated grains. This leads to lower starch but higher dietary fiber contents. Our team has examined protein composition, structure and interactions during processing of whole and refined IWG, as well as blends thereof. We are currently conducting shelf life studies to determine optimum storage conditions of intact kernels. Grains are analyzed for parameters indicative of chemical and enzymatic rancidity, in addition to phytochemical status. Ultimately, our goal is to find optimum processing conditions to maximize IWGs success as a sustainably sound alternative to other grains