| Lanzou alkaline hand stretched noodle (LASN) is a form of staple food in northwest China,which was originated from Lanzou. It was made into different widths, varying from ribbons tothreads by hand and dressed by delicious soup that was boiled with beef for eating. LASN hasbecame the distinguished local brand of fast food that can competed with world famous fastfood like Mcdonald's & KFC in recent years in China. However, the wheat qualityrequirements for LANS are confused until now. In order to help wheat breeders to select theLASN wheat cultivars and provide the quality parameters for millers, the wheat qualityrequirement of LASN were studied in the dissertation.81 samples were used in the experiment, which included 9 commercial flours and 72 wheatcultivars involving some popular wheat cultivars in Hexi corridor, some advanced lines as wellas some old wheat varieties of Gansu Province. The aim of this dissertation is to disclosefollowing aspects: (1) wheat normal quality requirement for LASN. Mainly research the effectof the seed quality, dough rheology and starch pasting properties on LASN. (2) The specialeffect of alkaline additive in LASN on starch pasting and dough mixing properties were studied.(3) The function of wheat glutenin on LASN and wheat quality. In order to identify the effectof quantity and composition of high molecular weigh glutenin subunits (HMW-GS) and lowmolecular weigh gluten subunits (LMW-GS) on LASN and wheat quality, isolating differentfraction of glutenin and mapping the composition of HMW-GS and LMW-GS by SDS-PAGEwere operated. The results as following were drawn out:(1) The wheat quality requirement for LASN. 72 spring wheat cultivars were made to LASNand the wheat flour quality as well as noodles quality was investigated. In totally, the wheatprotein quantity was more crucial than protein quality. The protein content, dry gluten content,wet gluten content, gluten index and SDS sediment volume has significantly influenced thenoodles tasting score at 1% level. As for the rheological dough properties tested by the ChopinAlveograph such as dough strength (W), index of elastic (I.e.), dough swelling (G), doughtenacity (P) and dough extensibility (L) showed the similar performance on the noodles tastingquality. The ideal quality parameters of wheat flours for LASN should be as follow: dry gluten≥11%, granule value :60～65%, SDS-sediment: 35～50ml,index of gluten≥90%, wet gluten≥30%, protein content: 12.5～13.5%, G: 23～28ml, P≥100mm and L: 100～140mm, W:230～330mJ,I.e.: 50～65. It also suggested that the dough strength should be stronger thanother type of Chinese noodles, similar to the bread dough strength.(2) Wheat Starch Pasting Properties Requirements for LASN. Wheat starch pastingproperties of 8 wheat samples and 7 commercial flours were investigated by RVA. Through thecorrelation and regression analysis, the results were found as follow. The high quality specialflour for LASN should has the high peak viscosity, high holding strength and high finalviscosity. Meanwhile the breakdown and the value of setback should be high, however thepasting temperature should be low. The sensory quality of cooked LASN correlate significantlywith follow starch properties: peak viscosity(r =0.593*), holding strength(r =0.533*),breakdown(r =0.548*)and final viscosity(r =0.567*). The stickiness and soft-hardness ofLASN were correlated with present pasting parameters strongly. The optimum ranges of starchpasting properties for top quality LASN (sensory score more than 80) and normal quality(sensory score more than 75) were forecasted by quadratic regression model. The top quality ofLASN flour should has following pasting characters: peak viscosity≥220RVU, holdingstrength≥140RVU, breakdown≥90RVU, final viscosity≥270RAU and setback≥125RAU;The normal quality of LASN: peak viscosity≥ 180RVU, holding strength≥ 85RVU,breakdown≥75RVU ,final viscosity≥175RAU and setback≥90RAU.(3) The effect...
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