Study On Influencing Factors Of Buckwheat Noodles Quality And Establishment And Verification Of Prediction Model

Noodles,as a traditional staple food in China,play an important role in people’s consumption structure.However,the evaluation methods of noodles in domestic and foreign studies are still based on traditional sensory evaluation at present,which has some shortcomings including subjectivity,easy to be influenced by external environment,complicated evaluation process,time-consuming,labor-intensive and so on.Therefore,it is of great significance to explore evaluation methods of noodle quality based on objective instrumental analysis and stoichiometry.In this paper,three common kinds of buckwheat on the market were taken as the research object.Based on physical and chemical characteristics of different buckwheat varieties and the final properties of buckwheat noodles,the apparent influence of buckwheat noodle quality was analyzed,and the mechanism of the influence of different buckwheat varieties on noodle quality was studied,and the correlation between buckwheat components and buckwheat noodle quality was explored.Finally,in order to quickly predict noodle quality and avoid the subjectivity of artificial sensory evaluation,a noodle quality prediction model was constructed based on the difference of buckwheat varieties which provided a basis for standardization,standardization and digitalization of buckwheat noodle quality discrimination.The specific research contents and results are as follows:Firstly,three common kinds of buckwheat sold in the market were used as raw materials to explore their apparent effects on the quality of buckwheat noodles,and the results were shown below.On the one hand,the addition of buckwheat flour not only reduced the integrity of the internal structure of noodles,but also the gluten strength and hardness of noodles.Besides,the thermal stability and shear resistance of noodles were poor after being added the buckwheat flour.The negative changes above led to the deterioration of the texture properties and tensile properties of noodles,which could reduce the overall sensory acceptability of noodles furthermore.For the other hand,though the cooking quality of noodles was reduced,the addition of 20%buckwheat and tartary buckwheat improved the cooking characteristics of noodles.In conclusion,the quality of noodles made of 20%buckwheat,10%tartary buckwheat and 10%black tartary buckwheat is better comprehensively.Secondly,in view of the apparent changes of different buckwheat varieties on the quality of buckwheat noodles,the mechanism of the apparent changes of buckwheat noodles was explored based on the physical and chemical properties of buckwheat flour and the final properties of buckwheat noodles,and the results were shown below.The water-holding capacity（13.70 g/g）,swelling capacity（9.40 g/g）and water absorption（8.99 g/g）of buckwheat were the highest,and the water-binding capacity（0.53 g/g）was the lowest,which had little difference in water solubility index.Besides,the particle size,bulk density and overall viscosity of buckwheat after gelatinization were higher than those of tartary buckwheat and black tartary buckwheat,and the gelatinization temperature of the three buckwheat powders were all below 100°C.Naturally,both of them were easy to be processed.For overall consideration,the processing applicability of noodles made from buckwheat was relatively good,and the acceptance of noodle final products was higher.Furthermore,the addition of buckwheat flour increased the values of T₀、T_pand T_c,and decreased the value ofΔH.Although the addition of buckwheat flour didn’t change the crystal structure of starch,but reduced the relative crystallinity of starch.The content ofβ-sheet structure decreased,and the stability of noodles decreased.Adding buckwheat flour to noodles could change the distribution of water in noodles,and with the increase of buckwheat flour addition,the transverse relaxation time T₂of water molecules shifted to the left,and the water freedom and total water content were reduced.Finally,Pearson Correlation Analysis showed that there was a high degree of multicollinearity not only among the fingers of noodle quality but also between the indicators of noodle and the basic components.Therefore,seven basic components of 13 samples were analyzed by principal component analysis,and two principal components,PC1 and PC2,were extracted,whose variance contribution rate was 69.3%and 18.1%respectively.The comprehensive score equation of the basic component content of noodles was established,which was PCS=0.339 Z_X1+0.337 Z_X2–0.246 Z_X3+0.326 Z_X4-0.229 Z_X5+0.226 Z_X6–0.125 Z_X7.Regression analysis was carried out between the comprehensive score of the basic components of raw materials obtained by principal component analysis and the total score of sensory evaluation,and a regression equation was established,which was y=-1.892 Z_X1–1.881 Z_X2+1.373 Z_X3–1.820 Z_X4+1.278 Z_X5–1.262 Z_X6+0.698 Z_X7+70.524（R²=0.953）.Finally,a noodle quality prediction model based on the difference of buckwheat components was obtained.In order to verify the feasibility of the evaluation method,sorghum,highland barley,quinoa,oats and buckwheat sold in market were selected to verify the model based on the basic components whose aim was to predict the comprehensive score of noodle quality.As a result,90%of the measured comprehensive score of noodle quality falled within the 95%confidence interval of the predicted value calculated by the model formula,which showed that the method of constructing noodle quality prediction model based on component differences was feasible,applicable and practical.