Effect Of The Addition Of Japonica Rice Flour On Mechanical Properties And Structure Of High Gluten Wheat Flour

Rice is one of the main food crops in our country,and there is a lot of nutritious food,which has become the focus of food researchers.In this paper,12 kinds of Japonica Rice from different regions of Heilongjiang Province were added to high gluten flour.The mechanical properties such as wet gluten content,gluten strength and creep characteristics of rice flour dough were studied by using AACC hand washing method,electronic gluten meter globograph-e and mcr102 rheometer.By using Osborne classification principle,FTIR and SEM,the protein components,protein secondary structure and disulfide bond determination were studied,and the effect mechanism of the addition of Japonica rice flour on the meso and micro properties of wheat dough was obtained.It can provide the corresponding basis for the application of Japonica rice flour in fermented food.The results show that:(1)The content of wet gluten decreased with the addition of rice flour,and the decrease range was different for different varieties of Japonica rice flour.The wet gluten content decreased from 31% to 17.5% when the rice flour gradient increased from 0% to 50%.The tensile value and rebound value decreased,and the torsional resistance of dough increased,which reflected the increase of gluten strength.With the increase of Japonica rice flour,the tensile value and rebound value of Ld9 flour increased,and the gluten strength decreased.(2)The creep properties of the mixed dough were measured,and the effect of the addition of rice flour on the viscoelasticity of the dough was obtained.On the whole,when Ld9 was added,the maximum strain of mixed flour dough would increase with the increase of the addition amount of Japonica rice flour.When M31 was added,the creep indexes were basically unchanged.When other varieties of Japonica rice flour were added,the maximum creep flexibility and instantaneous recovery creep flexibility decreased,and the zero shear viscosity increased.When Wy4 was added,the recovery ratio of mixed flour dough would increase with the increase of the addition amount,and the other The trend of the final recovery rate of dough with mixed flour decreased with the addition of Japonica rice.When the addition of Ld9,19,23,24 and 25 was 40%,the final recovery rate increased.(3)The correlation analysis of four protein components and their sum with total protein and mechanical properties of Different Japonica rice varieties was carried out.The sum of four protein components and their sum was positively correlated with total protein;the content of globulin and glutenin was positively correlated with the sum of protein components;the content of Glutenin was positively correlated with the content of globulin;the content of albumin was positively correlated with the content of alcohol soluble egg White content was negatively correlated.The difference of gliadin in rice flour plays an important role in the mixed dough system;the highly polymerized water-soluble protein also has an effect on the mechanical properties of dough,the albumin content has a great influence on the maximum creep flexibility,zero shear viscosity and instantaneous recovery flexibility,the globulin content has a strong positive correlation with the rebound value of gluten,and a strong negative correlation with zero shear viscosity;the gluten content has a strong positive correlation with the rebound value of gluten White has little effect on the whole.(4)The content of sulfhydryl group was determined after the protein was extracted and analyzed.It was found that the content of gluten had a great influence on the content of sulfhydryl group in the flour mixture.The content of total sulfhydryl group in Ld19 was positively correlated with the amount of added japonica rice flour,while the content of total sulfhydryl group in the other 11 kinds of Japonica wheat flour mixture was negatively correlated with the amount of added japonica rice flour,and the content of sulfhydryl group in the flour mixture was lower than that of high gluten wheat flour The difference of amino acid composition of rice protein in primary structure results in the decrease of the content of total and free sulfhydryl groups.(5)The results showed that the α-helix structure decreased with the increase of the addition of Japonica rice flour,but it did not change much after the addition of more than 10%.The irregular crimp structure shows an increasing state,but the regularity of increasing range is not strong.With the different amount of addition,they have a dynamic mutual conversion process.β-angle and β-fold structure sometimes increase and sometimes decrease,usually with little change.The irregular crimp structure and β-fold or β-corner structure,most of which are complementary to each other.α-helix / β-fold decreased with the addition of Japonica rice flour.The microstructure of gluten showed a porous three-dimensional network,and the gluten showed different states after the addition of Japonica rice flour,among which the mixed flour gluten network formed by Ld19,20,23,25,Lj31 and M31 was better.(6)Through single factor and orthogonal experiment,the best formula of premixed rice bread is determined as follows: the ratio of high gluten flour to rice flour is 11:9,among which the ratio of rice flour to glutinous rice flour is 5:5,the amount of water added is 60%,sugar powder is 12% and yeast is 1.0%.Butter 5%,salt 1%,milk powder 5%,gluten 10%,egg liquid10%.It is proved that the premixed rice bread produced by this formula has excellent taste,even and consistent baking surface color,which is cash yellow,sweet and delicious,soft taste,delicate organization,good baking and fermentation flavor of bread and light rice flour flavor,clear texture and good quality.