Study On Method Of Improving Processing Quality Of 50% Buckwheat Noodles And Its Mechanism

Buckwheat is a kind of high-quality food ingredient with rich nutrients and strong health care function.However,due to its low content of gluten,buckwheat flour is difficult to shape dough,which limits its application to pasta staple.Therefore,in this paper,pregelatinized buckwheat flour,wheat gluten,wheat flour with different gluten were added to improve the processing quality of 50% buckwheat noodles,and their improvement effects and mechanism were studied;When the processing quality of three recipes of noodles mentioned above,meeting the requirements of industrial production,analyze the quality and raw material cost of noodles to optimize the formula of 50% buckwheat noodles.The main research and results were summarized as follows:(1)Buckwheat flour was pregelatinized under different extrusion cooking conditions,and the fine structure of its starch was analyzed to explain the improvement mechanism of processing adaptability.The gel property was used as indicators to optimize the pregelatinizing process parameters.At last,quantify the effect of pregelatinized powder on the quality improvement of noodle processing by the texture evaluation of dough sheets.As a result,after extrusion cooking,buckwheat starch molecules are degraded to produce a specific chain length suitable for starch gel formation,wherein the chain length of DP6~50 is positively correlated with the starch gel strength.Pregelatinized buckwheat,which was extruded under the temperature of 200 oC,moisture content of 16 % and screw speed of 260 rpm,exhibited the best gel property of all.When buckwheat flour was replaced with 5%,10%,and 15%,the tensile strength of the dough sheets increased first and then decreased.Overall,pregelatinized buckwheat flour improved the processing characteristics(gel quality)by forming a specific chain length of amylopectin molecules(DP6~50)and moderately degraded amylose chains,when added at 10%,the processing performance of the 50% buckwheat noodle can be significantly improved.(2)Five gluten flours commercially available were substituted for wheat flour by 5%.The distribution of water,the content of glutenin macropolymer(GMP)andthe quality of gluten network in dough sheets were analyzed,studying the relationship between the quality of gluten with the processing performance of noodles,and determining the mechanism and key quality indicators of gluten flour for the improvement effect of the quality of noodle processing.The results showed that there were significant differences in the tensile strength of dough sheets when different varieties of gluten added,which was(significantly)positively correlated with the index and water absorption rate of gluten,and positively correlated with GMP content,related to the density of the gluten network and irrelated to the water distribution in dough sheets.Gluten flour has significant differences in the processing performance of noodles by affecting the quality of gluten network and GMP formation inside dough sheets,and its gluten index and water absorption rate can be used for evaluating the quality of gluten.(3)50 percent buckwheat noodles were made with three formulas,studying the processing performance,cooking quality and eating quality of their noodles,and calculating their raw material cost,to optimize the formula of 50 percent buckwheat noodles.The results showed that the dough sheet of formula 2(5% gluten added)had the highest tensile strength of all.With low cooking loss and high-water absorption,the cooked noodle of formula 2 exhibited high hardness and moderate adhesion by TPA data,and tendons and smoothness by sensory evaluation.Meanwhile,the raw material cost of the noodle of formula 2 is lower than formula 1(10% pregelatinized buckwheat flour added)and 3(50% high-gluten wheat flour added).It can be seen that formula 2 is more suitable for the improvement of the processing quality of 50%buckwheat noodles.