Effect Of Gliadin Subcomponents With Different Dissolution Characteristics On The Characteristics Of Chinese Steamed Bread Dough

The gliadin is the main component of the gluten network structure,so it plays a decisive role in the characteristics of the dough and the quality of chinese steamed bread.According to the Wayne classification method,the gliadin is divided into 8 sub-components by the solubility characteristics,and 5 sub-components(gli8,gli9,gli10,gli11,gli15)with higher content are selected to detect their properties and basic structure.Then adding them to special flour I and low-gluten flour according to the extraction rate,studying their effects on the properties of dough and the quality of chinese steamed bread.Therefore,these explain how they affect the characteristics of dough from these small molecular levels,provide theoretical guidance for improving the quality of flour,and provide theoretical references for solving problems such as shrinking of chinese steamed bread and bread cracking.According to the determination of the properties,the molecular weights of the gliadin(gli)and gliadin subcomponents gli8,gli9,gli10,gli11 and gli15 are approximately 31.52,22.83,17.29,14.85,30.85,30.00 kDa;their secondary structure is ?-sheet and ?-turn mainly;their hydrophilic amino acids,hydrophobic amino acids and the total amount of amino acids are gli > gli11 > gli8 > gli15 > gli9 > gli10;the isoelectric points of gli,gli8,gli9,gli10,gli11 and gli15 are 6.8,6.4,2.8,3.0,4.2,4.0;their surface hydrophobicity is gli15 > gli > gli11 >gli8 > gli10 > gli9;the denaturation temperatures of gli,gli8,gli9,gli10,gli11 and gli15 are68.32,107.66,93.71,105.58,82.95,121.40 °C;their total thiol content is gli11 > gli9 > gli >gli15 > gli10 > gli8.Through the effect of them on the rheological properties of dough,the results are as follows: the addition of gli8,gli9,gli10,gli11 and gli15 increases the water absorption of special flour I;In the process of proofing a special flour dough,adding gli11 and gli15 gives dough extensibility;gli8,gli9,gli11 and gli15 can enhance the gas holdability of special flour I dough;gli11 and gli15 decrease the tolerance of special flour I dough during the fermentation process.The addition of low-gluten flour of gli10 and gli11 has a larger evaluation value;gli11 increases the elongation of the low-gluten flour dough;and gli10 increases the gas-holding rate of the low-gluten flour dough.The study of them on the protein properties of the dough,the results showed that the addition of gli8,gli9,gli10,gli11 and gli15 increases the water absorption of special flour I;during the proofing process,gli9 has a certain influence on the disulfide bond of special flour I dough;adding them increases the ?-turn angle in the secondary structure of special flour I dough protein;gli11 and gli15 increase the disulfide bond of the low-glute flour dough;gli9promotes the formation of hydrogen bonds during the proofing of the low-gluten flour dough,and gli11 strengthens the disulfide bond in this process;adding them increases the ?-helix and?-sheet of the low-gluten flour dough.Analysis of the effect of water on the moisture distribution in dough by NMR,the results show that gli8,gli9,gli10 and gli15 enhance the fluidity of the strong binding water of special flour I dough;about special flour I dough after the proofing,the five sub-components enhanced dough water retention.These five sub-components in the low-gluten flour dough make the combination of water and other molecules stronger.The study of them on the dough structure,the results show that gli8 has an effect on the transverse structure of special flour I chinese steamed bread dough,and gli9 and gli10 have an effect on the longitudinal structure;gli10 and gli15 mainly affect the longitudinal structure of the low-gluten flour chinese steamed bread dough,and the network structure of the low-gluten flour dough with gli11 added is relatively tight.Through correlation analysis,it was found that the denaturation temperature,hydrophobic amino acid content and free sulfhydryl content of the gliadin subcomponent were significantly correlated with the dough characteristics of special flour I.Regarding the dough characteristics of the low-gluten flour,the ?-helix and ?-sheet content,the hydrophobic amino acid content,the denaturation temperature,the total sulfhydryl group and the disulfide bond content of the gliadin subcomponent were all significantly correlated.Through their research on the quality of chinese steamed bread,the results show that they have reduced the quality of special flour I chinese steamed bread,and the sensory evaluation has decreased;they can improve the quality of the low-gluten flour chinese steamed bread,among which gli11 is most significant.