Effects Of D-chiro-inositol Change In Buckwheat By Saccharomyces Cerevisiae Fermentation

Buckwheat which belongs to the Polygonaceae family adapts to cool, moist climates and short growing season. There are two varieties of agricultural cultured buckwheat: Fagopyrum tataricum Gaert and Fagopyrum esculentum Moench. Buckwheat contains high biological value protein, vitamins, minerals, flavanoids and so on. These ingredients have many physiological functions such as lowering blood sugar and blood fat, anticarcinogenic, antioxygen and eliminating free redicals. Researches discover that buckwheat seed contains fewer D-chiro-inositol(DCI) monomer and more of DCI derivatives named fagopyritol. It can effectually regulate blood sugar and ameliorate diabetic(especially II type diabetic) sympyom.DCI is the stereo-isomer of inositol. As a new generation insulin acceptor sensitizer it can effectually promote insulin function, lower blood sugar, triglyceride level and so on. Further research discovers that DCI has an important effect on the signal conduction process of insulin. When DCI is insufficient in human body, it can result in insulin resistance phenomenon. Therefore supplying with DCI can improve organism soma to insulin sensitivity and eliminate insulin resistance. DCI can fundamentally accommodates organism's physiological function and metabolic balance, lead to a low diabetic incidence.In this study, to develop a RP-HPLC method to determine D-chiro-inositol(DCI) in Fagopyrum tataricum seed, column temperature, mobile phase and velocity of flow were tested. The results shows when carried out at 30°C on a NH₂ column, eluted with a mobile phase consisting of a mixture of acetonitrile-water(70:30), flow rate in 1.0 mL/min, the calibration curve was linear within the concentration ranges of 1.340～8.040μg (r=0.9995). The average recovery was 96.74%. In addition, conditions and methods of extraction of DCI from buckwheat were investigated. Experimental result indicates: extract of 80% alcohol at temperature 25℃for 30 min, twice with ultrasonic enhancing is the best.The buckwheat sample was fermented with Saccharomyces cerevisiae. At first, factors as temperature, time, pH, solid-liquid ratio and inoculum concentration were tested. Experiments indicates that at temperature of 28℃, pH of 5.5, solid-liquid ratio of 1:10 and inoculum concentration of 2.51×10⁵ ,the fermentation carried out optimally at 34h. Based on the single factor experiment, orthogonal experiment was accomplished, the results indicate that the best combination is A₃B₂C₁D₂ representing of 34h fermentation duration at temperature of 28℃, pH of 5.5 and solid-liquid ratio of 1:10.