The Preparation And Physicochemical Characteristics,Digestibility Of Tartary Buckwheat Starch

The cereal food has been the most important food of human from time immemorial.In recent years,along with the improvement in the living standard of people,the incidence of chronic disease like diabetes mellitus,hyperlipidemia and so on is keeping raising because of the refined grain being the dominant on the dining table.Buckwheat,especially the tartary buckwheat has the irreplaceable and significant meaning in antioxidation,anticancer and decreasing the blood pressure,blood glucose as well as blood lipid.But over the years,the studies on buckwheat mainly focus on the antioxidants and protein,the starch in buckwheat is ignored.So in this article the lab preparation process of tartary buckwheat starch become the breakthrough point,tartary buckwheat flour as material,clear away the protein and fat using weak alkali solution and petroleum ether(30～60℃)respectively.Making the use of Box-Behneken designs for response surface methodology to get the optimum process of preparing tartary buckwheat starch removing flavonoids with the auxiliary of ultrasonic.The physicochemical characteristics of different tartary buckwheat starches have been comprehensive analysed and compare the in vitro digestion performance of different tartary buckwheat starches with the corn starch as control.The purpose is to sift the tartary buckwheat with strong physicochemical characteristics,low ingestion rate and good utilization ratio for further using and development.The main result of this paper:(1)The optimal process of flavonoids removing assisted by ultrasonic is:extraction temperature is 59.5℃,the ultrasonic power of extraction is 648 W,the liquid ratio is 23.5:1.The instruments,such as SEM,XRD and RVA-3 were used to test the nature of the tartary buckwheat starch.The result showed our starch has the standard type A crystal structure and complete gelatinization properties.It proves that our starches don’t be broken by the alkali and ultrasonic in the process(2)The content of amylose decreased in the following order:XiNong 9920>LiangShanXiaoMiQiao>XiNong 9940>XiNong 9909>ChuanQiao 1 Hao>corn starch.The crystal texture of tartary buckwheat is standard type A as the same as corn starch.The viscosities of tartary buckwheat starch paste are higher than corn starch at any testing time,and the luminousness of tartary buckwheat starch paste are lower than corn starch which shows that tartary buckwheat starch is easier to be retrograded(3)The in vitro digestion ratio of tartary buckwheat starch is lower than corn starch,XiNong 9920 is the lowest.Also,the starch components of samples are different,the ChuanQiao1Hao has the highest content of RS,there is no significant difference between the tartary buckwheat starch and corn starch in the content of RS.Corn starch has the highest content of RDS,and it is significantly higher XiNong 9940,XiNong 9920 and Liang Shan Xiao Mi Qiao.The content of SDS in the tartary buckwheat strach increases fast,XiNong9909 is the highest one.