Cereal Chem. 80(1): [52][53][54][55] Enzymes are good tool to modify wheat proteins by creating new bonds between the protein chains. In this study, the effect of the addition of glucose oxidase (GO) and transglutaminase (TG) on the wheat flour proteins is presented. The modification of wheat proteins was determined by analyzing the changes in gluten quality, alveograph parameters, and protein modifications. The amount of wet gluten increased with the addition of GO and TG, but the gluten quality was not improved in any case. Regarding the alveograph parameters, the effect of GO was readily evident obtaining wheat dough with higher tenacity and lower extensibility than the control, while TG led to doughs with lower tenacity and that were also less extensible. The protein modifications were characterized by free-zone capillary electrophoresis (FZCE). FZCE data indicated that TG polymerizes mainly glutenins and, of those, the high molecular weight glutenin subunits were the most affected. 2 Corresponding
The present study was aimed to investigate change in physicochemical characteristics and glutenin macropolymer (GMP) molecular weight distribution during postharvest wheat maturation. The freshly harvested wheat was stored under four different conditions (WT1, WT2, WT3 and WT4) for specified times. During maturation, the strengthening of wheat gluten structure was observed by increase in gluten index, swelling index of glutenin and sodium dodecyl sulphate (SDS) sedimentation value. The postharvest maturation resulted in contents increase of glutenin, glutenin/gliadin ratio, and GMP, and the decline of gliadin content. The contents of free sulfhydryl in GMP reduced, and S-S content rose during the whole maturation. Visible aggregates of GMP were observed in SDS-PAGE patterns for WT3 and WT4 samples after 4 weeks of storage. Moreover, in these two samples, polymerisation of gluten proteins into GMP was observed in size-exclusion high performance liquid chromatography patterns during storage. Some low molecular weight glutenin subunits (LMW-GS) incorporated into the aggregate, or combination of high molecular weight glutenin subunits and LMW-GS formed large polymeric glutenins by S-S linkage, and then assembled into GMP in postharvest wheat maturation. GMP polymerisation probably results in the improvement of wheat quality.
To clarify the effect of NaCl concentration (0–2.0%) on the formation of amyloid fibrils (AFs) in cooked wheat noodles, the morphology, surface hydrophobicity, secondary structure, molecular weight distribution, microstructure, and crystal structure of AFs were investigated in this paper. Fluorescence data and Congo red stain images confirmed the presence of AFs and revealed that the 0.4% NaCl concentration promoted the production of AFs. The surface hydrophobicity results showed that the hydrophobicity of AFs increased significantly from 3942.05 to 6117.57 when the salt concentration increased from 0 to 0.4%, indicating that hydrophobic interactions were critical for the formation of AFs. Size exclusion chromatography combined with gel electrophoresis plots showed that the effect of NaCl on the molecular weight of AFs was small and mainly distributed in the range of 5–7.1 KDa (equivalent to 40–56 amino acid residues). X-ray diffraction and AFM images showed that the 0.4% NaCl concentration promoted the formation and longitudinal growth of AFs, while higher NaCl concentrations inhibited the formation and expansion of AFs. This study contributes to the understanding of the mechanism of AF formation in wheat flour processing and provides new insight into wheat gluten aggregation behavior.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.