Development And Quality Improvement Of Whole Tartary Buckwheat Noodles

Tartary buckwheat is a crop of medicine and edible crop,which is rich in biological flavonoids,dietary fiber,resistant starch and other nutrients.However,the lack of gluten in Tartary buckwheat limits its addition in noodle products.In order to meet consumers'demand for nutritious and healthy staple foods,to develop the whole Tartary buckwheat noodles with sufficient physiological functions,in this paper,the Tartary buckwheat flour was extruded and then was mixed with the raw Tartary buckwheat flour to prepare the whole Tartary buckwheat noodles.The effect of extrusion pretreatment on the physicochemical properties of Tartary buckwheat flour and the effect of its physicochemical properties on the quality of the whole Tartary buckwheat noodles was investigated.different quality improvements were used to improve the quality of the whole Tartary buckwheat noodles.This study in order to provide the theoretical basis for the development and production of high-content Tartary buckwheat noodles.Firstly,the whole Tartary buckwheat flour was pre-pregelatinized by steaming-roasting or extrusion,and the effect of two different pretreatment methods on the physicochemical properties of Tartary buckwheat flour was compared.The results showed that after steaming,the starch in Tartary buckwheat flour showed A+V crystals,the weight-average molecular weight decreased by 13.65-28.81%,and the water absorption index(WAI)increased from 2.23to 2.54-3.48(p<0.05).There is no significant change in water soluble index(WSI)and cold-water viscosity.After extrusion,the crystalline structure of starch in Tartary buckwheat flour transformed from A-type to V-type after extrusion.The weight-average molecular weight of starch decreased by 80.23?88.7%after extrusion.Extrusion treatment increased the WAI of Tartary buckwheat flour from 2.23 to 4.52?7.12 significantly(p<0.05),and the WSI increased from 0.08 to 0.15?0.45 significantly(p<0.05).The cold-water viscosity of Tartary buckwheat flour increased from 11.68 Pa·s to a maximum of 654.77 Pa·s after extrusion,and the extruded Tartary buckwheat flour could form a gel in cold water,while the steaming-roasted Tartary buckwheat flour layered in cold water.The gel strength of Tartary buckwheat flour extruded at180 ^oC and 22%water content was the highest,which was 12.61 g.The gel strength of the extruded Tartary buckwheat flour increased with the increase of water content or the decrease of the temperature.Secondly,the dough sheet could be formed better with the addition of the extruded Tartary buckwheat flour,and the effect of different addition amount of the extruded Tartary buckwheat flour and the amount of water added in the dough mixing process on the processing quality and noodles quality of the whole Tartary buckwheat noodles was investigated.The results showed that the surface stickiness and the tensile strength of the dough sheet significantly increased(p<0.05),the hardness and chewiness of the cooked noodles increased,and the cooking loss rate increased by more than 20%with the the addition amount of Tartary buckwheat flour increased from 30%to 40%gradually when the amount of water added to the noodles was constant.When the addition amount of extruded Tartary buckwheat flour was 30%,35%,40%,and the amount of water added to the dough gradually increased from 34%to 37%,the surface stickiness of the dough sheet increased by 111.01%,74.48%,and 71.37%respectively,the tensile strength decreased by 22.87%,18.12%,11.46%respectively,and the cooking loss increased by 12.56%,20.20%and 21.0%(p<0.05).The surface stickiness of the dough sheet was the lowest,the tensile strength was moderate,and the cooking loss of the whole Tartary buckwheat noodles was the lowest when the the addition amount of extruded Tartary buckwheat flour was 30%,and the amount of water added to the noodles was 34%.Thirdly,the extruded Tartary buckwheat flour and untreated Tartary buckwheat flour were mixed at a ratio of 30:70 to make the whole Tartary buckwheat noodles.The effect of adding extruded Tartary buckwheat flour with different gel strength on the quality of the dough,dough sheet and noodles of the whole Tartary buckwheat noodles was investigated.The higher the gel strength of Tartary buckwheat flour,the better the viscoelasticity of the dough.The results of the stress relaxation test of the dough showed that with the increase of the gel strength of Tartary buckwheat flour,the greater the equilibrium elasticity coefficient(E₀),the decay elasticity coefficient(E₁),and the damping viscosity coefficient(?),the stronger the internal bonding force of the dough.The cold-water viscosity of the extruded Tartary buckwheat flour had a very significantly positive correlation(p<0.01)with the surface stickiness of the dough sheet.The gel strength was significantly(p<0.05)negatively correlated with the cooking loss of noodles,and was very significantly(p<0.01)positively correlated with the tensile strength of the dough sheet and the hardness of the cooked noodles.Therefore,the extruded Tartary buckwheat flour with lower cold-water viscosity and high gel strength was more suitable.for the production of the whole Tartary buckwheat noodles.The whole Tartary buckwheat noodles had the lowest surface stickiness,the highest tensile strength of the dough sheet,and the lowest cooking loss and breakage ratio of noodles using E3 flour with the gel strength of 12.61 g and a cold-water viscosity of 501.43 Pa·s.Finally,the effects of three hydrocolloids,exogenous proteins and enzyme on the cooking quality and textural property of whole Tartary buckwheat noodles were studied respectively.The addition of hydrocolloid enhanced the viscoelasticity of Tartary buckwheat dough.Among them,Artemisia sphaerocephala Krasch gum(ASKG)had the best effect on improving the elastic modulus G'and viscosity modulus G''.The addition of 1.0%Gluten-Free hydrocolloid significantly reduced the cooking loss of the whole Tartary buckwheat noodles from 19.27%to17.28%(p<0.05),and significantly increased the hardness and tensile strength of whole Tartary buckwheat noodles(p<0.05).Among the three hydrocolloids,GF has the best effect on improving the quality of whole Tartary buckwheat noodles.The addition of 5%whole egg liquid increased the hardness of the whole Tartary buckwheat noodles by 16.34%,the chewiness by 20.13%,the tensile strength by 42.74%,the tensile distance by 16.57%,and the cooking loss decreased from 19.26%to 13.90%significantly(p<0.05).The improvement effect of the whole egg liquid was better than soy isolate protein and egg white liquid on the whole Tartary buckwheat noodles.The addition of0.3%transglutaminase(TGase)significantly increased the hardness,chewiness and tensile strength,and significantly reduced the cooking loss of the whole Tartary buckwheat noodles.but the effect of TGase on cooking loss of noodles was not obvious.The combined use of 1%GF hydrocolloid,5%whole egg liquid and 0.3%TG reduced the cooking loss of whole Tartary buckwheat noodles by 39.2%(p<0.05)and increased the total sensory evaluation score.