Determination of the effect of high energy ultrasound application in tempering on flour quality of wheat

This research has been carried out under laboratory conditions. To determine the effect of soaking with ultrasound application to dampen hard wheat samples at one stage in tempering process was the prior goal. In the experiments, Bezostaya-1 wheat samples in different hardness levels (45, 65 and 75%) are used as material. The milling quality and qualitative properties of the flour were investigated. Results compared with the classic tempering process which has two stages tempering for hard and semi-hard wheat at the industrial applications. Ultrasonication of the samples has been applied by a probe-type ultrasound device. Because of experimental deviations, inevitable positive effect of ultrasonic tempering had not seen in the quality parameters of milling experiments like flour yield and energy consumption. But tempering with ultrasound application increased the speed of water intake and diffusion into the grain center. In the study, the wet gluten rates of the flour obtained by classical tempering process were 24.52% and the gluten index rate was 87.17%, while the results obtained by ultrasonic tempering were 22.70% and 93.33%, respectively. Thus it raised flour quality a little, possibly, due to low amount but better quality gluten coming from central endosperm in the flour obtained. Other analysis results in flour showed significant differences in some values of classical and ultrasonic tempering processes. As a result of ultrasonic tempering, the fineness rate (granulation) increased from 73.27% to 79.77%, ash content decreased from 0.61% to 0.55%, Zeleny sedimentation value decreased from 25.0 mL to 23.67 mL, flour stability increased from 9.76 min to 12.06 min, water absorption 59.1% decreased from 61.28%, softening resistance increased from 400.33 BU to 504.50 BU, maximum resistance increased from 420.50 BU to 536.16 BU. In bread trials, bread volume increased from 328.3 mL to 347.3 mL, and specific volume increased from 2.39 mL / g to 2.57 mL / g. These issues have been confirmed by some analysis such as fine granulation, low ash content, high gluten index, some farinogram, and extensigram properties, and finally better performance in bread making was observed.

Enriching LMW-GS alleles and strengthening gluten properties of common wheat through wide hybridization with wild emmer

Two advanced lines (BAd7-209 and BAd7-213) with identical high-molecular-weight glutenin subunit composition were obtained via wide hybridization between low-gluten cultivar chuannong16 (CN16) and wild emmer D97 (D97). BAd7-209 was better than BAd7-213, and both of them were much better than CN16 in a dough quality test. We found that BAd7-209 had more abundant and higher expression levels of low-molecular-weight glutenin subunit (LMW-GS) proteins than those of BAd7-213. Twenty-nine novel LMW-GS genes at Glu-A3 locus were isolated from BAd7-209, BAd7-213 and their parents. We found that all 29 LMW-GS genes possessed the same primary structure shared by other known LMW-GSs. Twenty-seven genes encode LMW-m-type subunits, and two encode LMW-i-type subunits. BAd7-209 had a higher number of LMW-GS genes than BAd7-213, CN16, and D97. Two wild emmer genes MG574329 and MG574330 were present in the two advanced lines. Most of the LMW-m-type genes showed minor nucleotide variations between wide hybrids and their parents that could be induced through the wide hybridization process. Our results demonstrated that the wild emmer LMW-GS alleles could be feasibly transferred and integrated into common wheat background via wide hybridization and the potential value of the wild emmer LMW-GS alleles in breeding programs designed to improve wheat flour quality.

Exploiting the reference genome sequence of hexaploid wheat: a proteomic study of flour proteins from the cultivar Chinese Spring

Although the economic value of wheat flour is determined by the complement of gluten proteins, these proteins have been challenging to study because of the complexity of the major protein groups and the tremendous sequence diversity among wheat cultivars. The completion of a high-quality wheat genome sequence from the reference wheat Chinese Spring recently facilitated the assembly and annotation of a complete set of gluten protein genes from a single cultivar, making it possible to link individual proteins in the flour to specific gene sequences. In a proteomic analysis of total wheat flour protein from Chinese Spring using quantitative two-dimensional gel electrophoresis combined with tandem mass spectrometry, gliadins or low-molecular-weight glutenin subunits were identified as the predominant proteins in 72 protein spots. Individual spots were associated with 40 of 56 Chinese Spring gene sequences, including 16 of 26 alpha gliadins, 10 of 11 gamma gliadins, six of seven omega gliadins, one of two delta gliadins, and nine of ten LMW-GS. Most genes that were not associated with protein spots were either expressed at low levels in endosperm or encoded proteins with high similarity to other proteins. A wide range of protein accumulation levels were observed and discrepancies between transcript levels and protein levels were noted. This work together with similar studies using other commercial cultivars should provide new insight into the molecular basis of wheat flour quality and allergenic potential.

Tracking celiac disease-triggering peptides and whole wheat flour quality as function of germination kinetics

Germination is already a well-accepted process by consumers with many products made from sprouted seeds or containing limited amounts of flour form sprouted grains. The present work aimed assessing the usefulness of germination in reducing gluten peptides associated with celiac disease, at the same time evaluating some technological features of the obtained germinated wheat. In the first part of the work, celiac disease (CD)-triggering peptides were tracked as a function of germination kinetics (from day 1 to day 6). Using simulated gastrointestinal digestion and liquid chromatography coupled to mass spectrometry, ten celiac disease triggering peptides were identified: seven peptides presumably involved in the adaptive immune response (TI) and three peptides mainly involved in the innate immune response (TT). All the identified peptides belonged to gliadins. TI track pattern showed three phases: the first two days displayed a significant degradation, a stability phase was observed from day 3 to day 5, and finally a drastic reduction occurred on the 6th day. For TT peptides, important degradation was exclusively observed at the 6th day. In the second part, some techno-functional features of germinated whole wheat flour were assessed to estimate its potential as an alternative to conventional flour. Functionality comparison of the non-germinated versus germinated flours revealed that germination significantly influenced solvents retention capacities as well as swelling and solubility. Thus, with a reduced amount of celiac disease triggering peptides, but also with different technological behavior compared to traditional wheat flour.