富含荞麦碱米饭的配方筛选及其对血糖生成指数的影响

摘要

A kind of buckwheat mixed rice with a good cooked taste and health-promoting functions was prepared with rice and buckwheat containing D-fagomine for providing people with an alternative choice of staple food, beneficial for reducing the glycemic index. A quantitative method to measure D-fagomine from 23 different origin buckwheat varieties was established by using ultra high-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS), and a kind of buckwheat with the highest concentration of D-fagomine was selected for cooking buckwheat mixed rice from the above buckwheat varieties. The content of main nutrient components, flavonoids and D-fagomine in this buckwheat were assayed and compared. The optimal cooking parameters were determined by using factorial design and sensory evaluation methods to evaluate the influence of addition ratio of buckwheat and water on the quality of cooked rice mixed with buckwheat. The postprandial hypoglycemic effect of this cooked rice mixture was investigated through the determination and comparison of digestion properties in vitro, glycemic index measured in vitro and in vivo and blood glucose change curves in rat. The results of experiment showed that Bendidali buckwheat, a kind of sweet buckwheat, had the highest concentration of D-fagomine (19.57 mg·g-1) among the 23 buckwheat varieties and was used to process the buckwheat mixed rice. Bendidali was rich in nutrition. According to the results of sensory evaluation, three suitable methods of cooking buckwheat mixed rice were screened. The cooked rice mixture with 24%(w/w, the ratio of buckwheat in the mixture) had the best taste among the three ratios of 8%, 24% and 48%(w/w). With the increasing of the amount of buckwheat, the glycemic index of the cooked rice mixture decreased. Compared with other two kinds of cooked rice mixed with common sweet buckwheat, the cooked rice added Bendidali buckwheat could decrease the glycemic index of rat in vivo in a dose-dependent manner. This postprandial hypoglycemic effect in vivo of rat should be attributed to the action of D-fagomine in buckwheat mixed rice. Compared with commercial common buckwheat, the Bendidali buckwheat had good postprandial hypoglycemic effect and was particularly suitable for processing cooked buckwheat mixed rice.%利用富含荞麦碱的荞麦米与大米制得一种有利于餐后血糖调节的复配米饭,为人们提供一种口感良好且具有保健功效的主食方案,对于降低米饭的血糖生成指数有重要意义.本试验通过超高效液相色谱串联四级杆质谱联用仪(UPLC-MS/MS)定量测定了23个不同产地或来源的荞麦中荞麦碱的含量,筛选出荞麦碱含量最高的荞麦,并对其主要营养成分和荞麦碱及总黄酮类化合物进行测定和比较,将其确定为制备复配米饭的荞麦米原料.采用析因设计和感官评定方法分析荞麦米、大米和水的添加比例对荞麦复配米饭品质的影响,确定最佳的制备工艺参数.对荞麦复配米饭的体外消化特性、体外血糖生成指数(GI)、大鼠的餐后血糖响应曲线以及体内外血糖生成指数(GI)值进行测定和比较,对其降低餐后血糖功效进行评价.结果表明:本地大粒(荞麦品种名称)荞麦米中荞麦碱含量最高,为19.57mg·g-1,且含有丰富的营养成分,因而将其作为本试验制备复配米饭的荞麦米原料.根据感官评定结果,获得3种荞麦复配米饭的制备方案,荞麦米添加量分别为8%,24%和48%(w/w,荞麦米/总米量),其中添加24%荞麦米煮制的复配米饭风味与品质最佳.随着荞麦米添加量的增加,荞麦复配米饭的GI值呈下降趋势.与市售甜荞米制成的复配米饭相比,本地大粒复配米饭能呈剂量依赖性地显著降低大鼠体内GI值,推测是由于复配米饭中的荞麦碱起到了主要的降低餐后血糖的功效.故与一般市售甜荞相比,以富含荞麦碱的本地大粒为原料制成的荞麦复配米饭可显著性地降低米饭的GI值,具有良好的降低餐后血糖的功效.