Studies On Effects Of Soybean Polysaccharide On Flour Quality

With the improvement of living standards,people pay more attention to natural food additives.Soybean polysaccharides are also popular because of their unique spherical structure and natural sources.It is a by-product of soybean oil production and contains a large amount of dietary fiber.Soy polysaccharides include soluble soybean polysaccharides and soybean dietary fiber.In this paper,two soluble soybean polysaccharides and soybean dietary fiber with different molecular weights were selected,and the changes of dough properties and wet-fresh noodles quality after adding soybean polysaccharide to three groups of flour were studied;The changes of physicochemical and structural properties of soybean polysaccharide-gluten protein after separation of starch and gluten were studied;The changes of physicochemical and structural properties of soybean polysaccharide-starch after separation of starch and gluten protein were studied.(1)The effects of soybean polysaccharide on dough properties and quality of wet-fresh noodles were studied.The results shown,the addition of SSPS1 and SSPS2 increased the water absorption of three groups of dough,decreased the tensile resistance of dough,increased the elongation,decreased the peak viscosity and the setback,and SSPS2 was less than SSPS1.The breakdown of the three groups of flour increased,and the SSPS2 was greater than SSPS1,indicating that adding SSPS2 and SSPS1 could inhibit the aging of the three flour.The addition SSPS1 increased the settlement value and GMP content of the three groups of flour,which indicated that the quality and quantity of gluten protein were improved,and the SSPS1 and SSPS2 increased the hydroxy content of dough,so that the hydrogen bonding strength of water molecules in dough and the moisture content of dough system increased.The addition of SSPS1 and SSPS2 reduced the hardness and adhesionness of the three groups of noodles.The tensile fracture strength of the noodles decreased and the tensile fracture distance increased.Adding SDF increased the tensile resistance of the three groups of dough,reduced the elongation,and increased the peak viscosity and setback,this was because the binding strength of dough to water molecules was strengthened,the water molecular content of dough system increased,and the water molecules redistributed.After adding SDF,the hardness of the three groups of noodles increased,the tensile fracture strength increased,and the tensile fracture distance decreased.The cooking loss rate of the three groups of noodles after adding 3 kinds of polysaccharides decreased.(2)The effects of soybean polysaccharide on gluten protein properties were studied.The results shown,with the addition of SSPS1 and SSPS2,the G' and G" of three kinds of polysaccharide-gluten protein decreased,the degree of reduction was: SSPS2>SSPS1.All tan? were increased,and the degree of increase was: SSPS2>SSPS1.The addition of SSPS1 and SSPS2 to increased the shape variables in the creep stage of gluten protein and the time to recover to the minimum shape variables.The negative effects of SSPS1 on gluten protein creep-recovery were smaller compared to SSPS2.The addition of SSPS1 and SSPS2 significantly increased the-SH content of three groups of gluten proteins,and the increase was related to the type and amount of polysaccharides added.After adding SDF,the dynamic frequency sweep test of the three groups of gluten protein did not change much more,the shape variable of the creep stage of gluten protein decreased slightly,and the time of the minimum shape variable decreased slightly.When the addition amount was greater than 0.3%,the three soybean polysaccharides reduced the noncovalent interaction of gluten protein,reduced hydrophobic interactions between proteins.The hydrogen bond and hydrophobic interaction between soybean polysaccharide and gluten protein were found.The secondary structure of gluten protein was more orderly,the gluten protein was filamentous,and the gluten protein network was more open.At the same time,soluble soybean polysaccharides were more likely to interact with gluten proteins,and the stronger electrostatic repulsion of SSPS2 was one of the reasons for the more open gluten network.In addition,the worse the gluten strength of gluten protein,the worse the ability to resist the negative corresponding soybean polysaccharide.(3)The effects of soybean polysaccharide on starch properties were studied.The results shown,with the addition of SSPS1 and SSPS2,the solubility and swelling power of three groups of starch were increased,the viscosity and setback of starch decreased significantly,and the(Tc-To)of starch increased,?H decreased,and the effect of SSPS2 on starch properties was greater.This was because the SSPS1 and SSPS2 were spherical structure,the degree of branching was high,they had steric hindrance,they were not easy to occur selvesaggregation phenomenon,they could interact with starch to delay starch aging,and the esterification degree of SSPS2 was lower,they were easier for starch to interact.And crystallinity and gel hardness of starch were reduced.The SDF had little effect on solubility and swelling power of three groups of starch,and(Tc-To)increased,starch breakdown and setback increased,?H decreased.At the same time,the starch made from XF flour with high gluten was greatly affected by soluble soybean polysaccharide.In summary,the interaction between soybean polysaccharides with different solubility and flour was different.The insoluble soybean polysaccharide(soybean dietary fiber)mainly effected the properties of dough,gluten protein and starch by improving the water content of dough system and competitived water absorption with gluten protein and starch.Soluble soybean polysaccharide has a unique spherical structure,which not only has strong water absorption but also interacts with gluten protein and starch.The esterification degree of soluble soybean polysaccharide is also the main factor affecting the properties of flour dough,gluten protein and starch with different gluten forces.the smaller the esterification degree,the greater the polarity of soluble soybean polysaccharide,the greater the electrostatic repulsion,and the greater the influence on dough,starch and gluten protein.