Study On Physicochemical Characters Of Tartary Buckwheat Starch From Different Regions

The tartary buckwheat is an important crop for food and economy,which is mainly distributed in Yunnan,Sichuan,Guizhou,Southern Tibet.The tartary buckwheat rich in flavonoids,vitamins,minerals,chlorophyll,vitamin P etc,is a set nutrition,health,diet in one natural food resource.Starch,which is one of main components in the tartary buckwheat,the physicochemical characters and origins of tartary buckwheat impact the processing and utilization of products and industrial development.Therefore,revealing the physicochemical characters of tartary buckwheat,study on the difference of starch physicochemical characters of different varieties and producing area,which have important realistic significance on improving rural economies,rural incomes and buckwheat industrial development.With new-bred varieties tartary buckwheat as material,study on products quality characteristics in 3 typical tartary buckwheat ecological climate growing zone and the granule morphology,the X-ray crystal diffraction,transparencies,gelatinization,freeze-thaw stability,viscosities,thermodynamic properties andgel structure features of their starch granules were measured,along with the expression of starch physicochemical characters in different ecotope.The paper draws the main conclusions as follows:(1)The plant reproductive traits,economic traits and grain yield of different tartary buckwheat varieties and the same variety in different regions were different.From analysis of variance showed the yield oftartary buckwheat in different regions had significant difference.Varieties and regions interaction effects had highly significant difference,which indicate that the high yield and adaptability of each varieties in different regions had significant difference.Among the yield of the tested varieties were the top three for Jinqiaomai(ku)-6,Dingku2001-9,Yunqiao-3,the yield respectively was2625.6,2610.0 and 2524.4 kg/hm2;Three years' average yields of Shaanxi Yulin,Shanxi Wuzhai and Inner Mongolia Chifeng respectively was1463.3,578.3 and 3148.7kg/hm2;the yield of tartary buckwheat in Inner Mongolia Chifeng is maximum,the yield is stable and had little difference,which is the suitable production area.(2)The tartary buckwheat starch granules had irregular polygonous and global shapes and the granules of the varieties with the former shapes were larger and numbered more than their ones with the latter shapes.The granule diameters of the test varieties ranged within 2-14 ?m.Small and medium-sized starch granules are the key component of the tartary buckwheat,the average particle size of the tartary buckwheat starch granules was 6.8?m,which is lower than that of com.The transparency of test varieties tartary buckwheat and com had the significant difference.The average transparency of the tartary buckwheat starch paste was 7.68%,the variable coefficient is 2.55%,which was lower than that of corn;The starch paste retrogradation and freeze-thaw stability of the varieties tended to better than corn starch paste;The tartary buckwheat starch paste peak viscosity,trough viscosities,final viscosities,breakdowns and setbacks are higher than those of corn starch paste;Tartary buckwheat starch paste has strong hot viscosity stability,cold viscosity stability and gel forming ability;The gelatinization temperature scope of the starch paste was from 65.87? to 78.41?,and the peak temperature was 70.88 ?,which were lower than that of corn starch paste.Tartary buckwheat starch is the ideal raw material in the food industry as the thickener,binder and starch gel products.(3)In different regions,the starch granule morphology of different varieties of tartary buckwheat is similar;the crystal diffraction pattern type is all A;The starch paste transparencies of different regions ranked:Shannxi Yulin>Inner Mongolia Chifeng>Shanxi Wuzhai;The starch paste retrogradation of the varieties tended to increase quickly at first and then slowly with time,the rate of the starch paste retrogradation in the 3 ecotopes were not all the same,ranked Inner Mongolia Chifeng>Shannxi Yulin>Shanxi Wuzhai,and the freezing and thawing drainage rate of the starch ranked:Inner Mongolia Chifeng>Shannxi Yulin>Shanxi Wuzhai.Variance analysis showed that the gelatinization characteristic and thermal characteristic are all significantly effected by varieties,environment.The starch peak viscosities,breakdowns and setbacks of 05-43 are the highest,which is significantly higher than other varieties;The starch peak viscosity and final viscosity of Jiujiangkuqiao are the lowest,after that is KQ10-13,the breakdowns and setbacks of KQ10-13 are lower,which indicate that the viscosity is low,thermal paste stability and cold paste stability are better.In different regions,the viscosity parameters of tartary buckwheat starch are inconsistent.The peak viscosity,the final viscosity,breakdowns and setbacks of Shannxi Yulin is the highest,which is significantly higher than other regions;the breakdowns and setbacks of Shanxi Wuzhai is the lowest 355cP?613 cP,which is significantly lower than other regions;which indicate that thermal paste stability and cold paste stability of Shanxi Wuzhai are better,the viscosity of Shannxi Yulin and Inner Mongolia Chifeng are better.The phase transition process of starch gelatinization,the average To,Tp and Tc of Shannxi Yulin are the lowest,which indicate that the starch in Shannxi Yulin is easier to gelatinization;the average To,Tp and Tc of Inner Mongolia Chifeng are the highest,which indicate that the starch in Inner Mongolia Chifeng is difficult to gelatinization;the average AH of Yunqiao-3,KQ10-13and XH-03 are lower,which is easier to gelatinization.In different regions,the hardness,gumminess and chewiness of Shannxi Yulin tartary buckwheat starch gel structure are significantly higher than those of Inner Mongolia Chifeng and Shanxi Wuzhai;Which indicate that tartary buckwheat starch gel of Shaanxi Yulin have higher hardness,good chewiness,with the good quality and structure features.