The Effect Of Starch Component And Its Ramification On Noodle Quality

Noodle is one of the traditional staple food in China,which has the advantages of good taste,easy cooking,good nutrition,and has a large number of consumer groups in the world.Starch is the main component of the raw material for making noodles.Therefore,the composition and physical and chemical properties of starch have an important influence on the quality of noodles.The study on the effect of starch composition on noodle quality can provide reference and theoretical basis for formulation of noodle powder standard and wheat breeding.In this study,A and B type starch was obtained by the separation from wheat flour,acetylated starch and carboxylic starch was obtained by acetylation and carboxylation treatment of starch in wheat flour.The physical and chemical properties of starch were determined by Laser particle size analyzer,X-ray diffraction and other instruments.Six kinds of corresponding flour samples were obtained by mixing the starch(A and B type starch,acetylated starch and starch without acetylation,carboxylic starch and starch without carboxylation)with the flour according to the ratio of 1:4.The effect of starch on flour quality(Flour paste viscosity and gluten quality)was studied by using rapid viscosity analyzer,gluten washing apparatus and other equipment.Six kinds of noodle samples were prepared by the same process with the corresponding flour samples as the raw material.The effect of starch on noodle quality(Water distribution of noodle,Energy change during heating,Cooking quality,Textural properties)was studied by using low field nuclear magnetic resonance,DMA,texture analyzer and other equipments.The differences of physical and chemical properties of wheat A and B starch and the effect of starch on flour quality and noodle quality were analyzed by the method of separation and recombination.Results showed: A,B type starch granule surface is smooth,the particle size of A type starch was generally greater than 10 ?m,the shape was circular;most B type starch size was less than 10 ?m,and the shape was oval or irregular,which was easy to adhere to each other in the aqueous solution.Starch content,amylose content,the ratio of amylose to amylopectin of A type starch was relatively larger,damaged starch content was smaller;the crystal forms of wheat A and B type starch were A type,and the relative crystallinity of wheat A starch was relatively larger;the swelling power and water holding capacity of wheat A starch were smaller,and the solubility was larger;the peak viscosity,lowest viscosity and final viscosity of flour with A starch were larger;there was no significant difference in the gluten quality of wheat A and B type starch;transverse relaxation time and weak binding water peak ratio of deep water and weak bound water in noodles with A starch were larger,deep binding water peak ratio is smaller;the storage modulus of noodles showed progressive increase first and then almost remained unchanged with temperature up,the loss modulus increased first and then decreased,noodles with A starch had larger storage modulus and loss modulus during the heating process;there were less dry matter absorption rate,larger dry matter loss rate,smaller hardness,adhesiveness,chewiness,tensile strength and tensile distance in the noodles with A starch.Under mild conditions,a low degree of substitution of acetylated starch was prepared by using acetic anhydride as esterification agent.The paper mainly studied the differences of physical and chemical properties and the effect on the quality of noodle with acetylated starch and natural starch.The results indicated that the surface of acetylated starch becomes rough and had slight damage and adhesion.There was no obvious change in the interior of the particles which showed that acetylation of starch mainly occurred on the surface of the particles.There was no significant difference in starch content,amylose content,and the ratio of amylose to amylopectin between acetylated starch and natural starch.In this condition,the acetylation of starch did not affect the original composition,the crystal form of starch was unchanged,and the relative crystallinity had not obvious change.The swelling power and the capacity of water holding of the acetylated starch were higher than natural starch,and the solubility was less.The peak viscosity,trough viscosity and final viscosity of the flour which contained acetylated starch increased.The wet gluten content and dry gluten content of acetylated starch had no significant difference with natural starch,while gluten index of acetylated starch reduced.The ratio of bound water decreased,the weakly bonded water increased in the noodles which contained acetylated starch.The storage modulus and loss modulus of the noodles which contained acetylated starch were less than that of the native sample after the noodles were gelatinized.There were larger dry matter absorption rate,less dry matter loss rate,smaller hardness,adhesiveness,chewiness,larger tensile strength and tensile distance in the noodles with acetylated starch.Under mild conditions,the carboxylic starch with low carboxyl content was prepared with 30% hydrogen peroxide as oxidant.The difference of physicochemical properties between oxidized starch and native starch was analyzed to study the relationship between physicochemical properties and the quality of fresh noodle.The results indicated that the surface and the edge of carboxylic starch were destroyed,and carboxylic starch had larger particle size because of adhesion.Carboxylic starch had less starch content,amylose content,the ratio of amylose to amylopectin.Compared with native starch,the crystal of carboxylic starch was unchanged,the ability to combine the lipid increased,the swelling power and water holding capacity decreased,and the solubility increased.The peak viscosity,trough viscosity and final viscosity of flour contained carboxylic starch reduced.There were no significant difference in wet gluten content,gluten index and dry gluten content between flour contained native starch and carboxylic starch.The T2 relaxation time of bound water and weakly bonded water in noodles contained native starch and carboxylic starch showed no significant difference.The ratio of bound water decreased,the weakly bonded water increased in the fresh noodles which contained carboxylic starch.During the heating process,the storage modulus and loss modulus of the noodles which contained oxidized starch were less.There were less dry matter absorption rate,larger dry matter loss rate,smaller hardness,adhesiveness,chewiness,larger tensile strength and tensile distance in the noodles with carboxylic starch.The use of oxidized starch could improve the tensile properties of noodles.