Identification of gluten-like proteins in selected pod bearing leguminous tree seeds

The protein composition, molecular weight distribution, and rheological properties of honey locust, mesquite, Kentucky coffee tree, and carob seed germs were compared against wheat gluten. Polymeric and Osborne fractionation protocols were used to assess biochemical properties. Dynamic oscillatory shear tests were performed to evaluate protein functionality. All samples had similar ratios of protein fractions as well as high molecular weight disulfide linked proteins except for the Kentucky coffee tree germ proteins, which were found to have lower molecular weight proteins with little disulfide polymerization. Samples were rich in acidic and polar amino acids (glutamic acid and arginine,). Rheological analyses showed that vital wheat gluten had the most stable network, while Kentucky coffee seed proteins had the weakest. High molecular weight disulfide linked glutenous proteins are a common, but not universal feature of pod bearing leguminous trees.

Fundamental characterization of wheat gluten

Vital wheat gluten plays an important role in the food industry, especially in baking to help standardize dough properties and improve bread volume. However, a fundamental characterization of a wide variety of vital gluten samples is not available so far. This would be necessary to relate compositional characteristics to the production process. Therefore, we analyzed the content of crude protein, starch, lipids and ash, oil and water absorption capacity, particle size distribution, gluten protein composition and spectroscopic properties of 39 vital gluten samples from 6 different suppliers. Principle component analysis of all analytical parameters revealed that the samples from one specialized vital gluten manufacturer had a different composition and a greater variability compared to all other samples from wheat starch producers. While the composition of vital gluten samples from the same manufacturer was similar and the score plot showed a cluster formation for samples from three suppliers, the variability over all samples was comparatively low. The samples from the other suppliers were too similar altogether so that it was hardly possible to identify clear differences, also related to functionality.

The effect of additives combination on rheological properties of dough and quality of bread with Agaricus bisporus powder

The bread with Agaricus bisporus powder has the defects of poor texture and taste, so it is necessary to optimize the appropriate additives in order to improve its quality. The purpose of this study was to evaluate improvement of the combination of vital wheat gluten, sucrose fatty acid esters and cellulase on the improved Agaricus bisporus powder bread (IABPB), with wheat bread (WB) and bread with Agaricus bisporus powder (ABPB) as control. The results of rheological properties indicated the dough samples improved with three improvers had higher solid-like behaviour than the control sample. The results of nutritional quality analysis showed that the protein and dietary fiber content of IABPB was higher than those of WB and ABPB, but the fat content was relatively low. In addition, the additives combination could effectively improve the baking quality of ABPB. Compared with ABPB without additives, the specific volume increased by 21.22%, the brightness of bread crumb increased by 8.75%, but the crumb hardness decreased by 32.57%. Furthermore, the study on texture property and water migration during the storage showed that the addition of three improvers could delay the aging of bread. Therefore, it was feasible to use additives combination as a special quality improver for ABPB, which could effectively improve its quality.

Thermal Degradation and Water Uptake of Biodegradable Resin Prepared from Millet Flour and Wheat Gluten Crosslinked with Epoxydized Vegetable Oils

The degradation temperatures (DTs), heat stability (IPDT), degradation kinetics, and water uptake of epoxy resin were investigated using thermogravimetric analysis. Epoxy resins were prepared by crosslinking epoxydized oils with vital wheat gluten (VG) and millet flour. The reactions included three oils (cottonseed, sesame, and sunflower) and three levels of zinc chloride (ZC) (1, 2, and 3%). The apparent activation energy (Ea) was calculated using the Flynn–Wall–Ozawa method. The DT increased at higher heating rates within the same ZC level of the same oil type. Cottonseed oil exhibited the highest DT. The highest IPDT was 637°C of the sunflower oil/millet resin (3% ZC), and the least was the cottonseed/millet (1% ZC) at 479°C. The sesame-millet resin exhibited the highest Ea (622 KJ/mol) followed by sunflower-gluten (496 KJ/mol) and sesame-gluten (454 KJ/mol). The profiles of all resins point to a multistep degradation, but some of the profiles display two dominant kinetic processes, and the remaining resins showed three processes. The variation in crosslinking density between the oils is attributable to the different amounts of oxirane rings which are associated with the double bonds of the fatty acid of the oils. Like other parameters, the water uptake was affected by the ZC content, where most of the resins did not reach water uptake equilibrium. Nonetheless, the 3% ZC resin reached equilibrium after 5 days of immersion.