| As a gluten-free food crop,tiger nut has high nutritional value,but because it did not contain gluten protein,it was not easy to form dough,which limits its processing and utilization in flour products.Therefore,the application of tiger nut powder in flour products can not only improve the nutritional characteristics of flour products,but also increase the processing and utilization of tiger nut,which may make tiger nut become the main food crop.In this paper,wheat flour was used as the control group to study the gelatinization,flour properties and dough rheological properties of tiger nut wheat mixed flour(in which tiger nut powder accounted for 0%,10%,20%,30%,40%,50%,respectively).Different mixed flour were used to make noodles,and the texture properties,cooking quality,color difference analysis,in vitro digestibility,protein secondary structure,water distribution and flavor of noodles were analyzed.the effects of tiger nut powder on dough processability and noodle quality were obtained.The main contents and results are as follows:1.The main results are as follows: 1.There were obvious differences in gelatinization,flour properties and dough rheological properties of different proportions of tiger nut and wheat flour.tiger nut powder does not contain gluten protein,and when the addition amount was less than 40%,the weakening of dough shows an upward trend,while the flour quality index and water absorption show a downward trend,and the dough formation time was shortened.More than 30% of the tiger nut flour dough was damaged and was not suitable for making noodles.The initial gelatinization temperature and peak temperature of mixed powder increased with the addition of tiger nut powder.the initial gelatinization temperature of pure tiger nut powder was 71.4℃,which was 12.73℃ higher than that of pure wheat.The viscoelastic properties of dough increased with the increase of tiger nut flour.Because tanδ<1,it indicated that tiger nut wheat dough showed solid-like properties.Compared with pure wheat dough,different proportions of tiger nut flour had different tanδ values,and did not show obvious change rule with the increase of tiger nut flour addition.It can be known from the negative correlation between dough viscoelasticity and noodle stretching force,stretching distance and recovery.The more tiger nut powder is added,the worse its processing performance is.2.The dry matter loss rate and strip breaking rate of noodles increased significantly with the increase of the amount of tiger nut bean powder(P<0.05).When the tiger nut powder was added to 50%,the dry matter loss rate of noodles was33.35%,and the strip breaking rate was 45.22%.The tensile test could not be carried out because the strip breaking rate was too high.The hardness and chewiness of noodles increased with the addition of tiger nut powder,but the recovery and cohesion of noodles became worse,the surface of noodles was rough and the toughness was poor.The L value of noodles decreased,the values of a and b increased,and the noodle powder treated by freeze-drying was brighter than that of heated noodle powder.The correlation between noodle texture properties and dough rheological properties was analyzed.The viscoelasticity of dough was negatively correlated with dough recovery,tensile distance and tensile force(P<0.05),but positively correlated with noodle chewiness and hardness.The hardness and chewiness of noodles were negatively correlated with the amount of water added to the dough.Among the noodle texture indexes,the greater the noodle hardness and the better the chewiness,the worse the recovery and cohesion of the noodles,the shorter the stretching distance and the smaller the tensile force.3.The addition of tiger nut powder increased the content of slow digestible starch in the mixed powder system and reduced the in vitro digestibility of noodles.The in vitro digestibility of pure wheat noodles at 120 min was 62%,and that of wheat noodles with 30% was 52%,which decreased by 10%.The addition of tiger nut powder had no obvious effect on the secondary structure of protein in noodle powder;the main state of water in noodle was bound water and non-flowing water,and the addition of tiger nut increased the relaxation time T2,and the bound water in noodle was transformed into non-flowing water,and the more signal intensity peak was shifted to the right,which was not conducive to the quality of noodles.Aldehydes are the key flavor substances of noodles,with grass flavor,citrus flavor and fruit flavor.The content of aldehydes tiger nut is 7.68 μg/kg more than that of pure wheat noodles.Eucalyptus oleol was detected in wheat noodles,which was not detected in pure wheat noodles,and the addition of tiger nut enriched the flavor of noodles. |
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