Study On Extracting Anthocyanin From Black Rice And Its Stability In Alcoholic Drink

Anthocyanin belongs to flavonoids polyphenols compounds. It is consist of two parts—the anthocyanidin and the saccharide ligand. In the natural state, the two parts through anthocyanin and monosaccharides connected by glycosidic bonds then forms glycosides that exists in fruits, stems, cell liquid from leaves organs. As anthocyanin has the characteristics of safety, non-toxic, odourless, vivid bright colour and abundant resources, it has a certain nutritional value and pharmacological function, and it also has been widespread used in food, medicine, pharmacy and cosmetic fields. However, the research on anthocyanin from black rice is still in the initial starting stage in terms of industrial production and industrialization development, therefore, black rice anthocyanin still has many unsolved problems in both of the food and pharmaceutical industries.This essay based on the working foudations of Research on Anthocyanin Pigments from Black Rice （Natural Science Fund Project of Shaanxi Province 02C126）; Research on Exploitation and Utilization of Shaanxi Special Rice Resource （ Provincial Department of Science and Technology Key Lab Special Project 06KJZ-06）; Research on Separation & Purification and Mechanization Technology of Black Rice Pigment （ Provincial Department of Science and Technology Key Lab Special Project 08JZ-22）; Three Anthocyanin Capsules’Development and Pilot-scale production（The Special Breakthrough and Development Project of South Shaanxi 08SNTPZX-HZ01-1 ）, we start the researching works as（1） Optimizing the extraction conditions of black rice anthocyanin （2） The stability of anthocyanin from black rice in wine solution system （3） Separate and prepare black rice anthocyanin through preparative liquid technique （4）Analysising anthocyanin from black rice through liquid chromatography, the results of these works are listed as follows:（1）Taking the density gradient cyanidin standards as experiment materials and 535nm as working wave, we test cyanidin absorbance in different concentrations respectively. Taking the cyanidin concentration as （X） and its absorbance as （Y） , depicting the working curve of density gradient cyanidin, acquiring the absorbance and concentration regression equation of cyanidin:Y=0.1726X-0.0017. According to the regression equation establishs a calculation method of black rice anthocyanin extraction amount:M=（y+ 0.0017）/ 0.1726×0.0424/25×V×n / m. Taking these as the determination and calculation working platform of black rice anthocyanin extraction amount, and taking“HeiShuai”---the black rice new variety as experiment materials, conducting the single factor experiment,then acquiring the optimum results in different factor impacts. According to the Box-Behnken principle from the Design Expert 7.0.0 software. Selecting the main factors which influences the black rice anthocyanin extraction and then designing 30 response surface groups, based on these experiment results found response surface experiment regression equation: Y=1.46+6.333E-003x₁-2.917E-003x₂+7.417E-003x₃+0.012x₄+7.500E-003x₁x₂- 0.010x₁x₃-0.027x₁x₄-8.750E-003x₂x₃+1.000E-003x₂x₄+0.027x₃x₄-0.036x₁²-0.046x₂²-0.081x₃²-0.075x₄².The the regression equation show the extreme value theory of black rice anthocyanin is 1.430mg/g, and the correspondent technical parameters are: alcoholic concentration 68%, hydrogen chloride concentration 20%, feedstock ratio 1:9.4, temperature 84℃. Taking the technical parameters as working conditions, conducting black rice anthocyanin extraction and verification experiment, the factual black rice anthocyanin extraction amount is 1.424%, and the relative deviation between factual results and theoretical calculation results is only 0.42%. Overall ,these statistics indicates that the regression equations and technical parameters getting from response surface analysis method are reliable and practical enough to guide pilot-scale production work development.（2） Taking black rice base wine and black rice extraction content as experimental materials, researching black rice anthocyanin absorbance change with time regularity in different conditions. The results show that in the conditions of the light group, indoor nature light group, the low-temperature dark group, and color protection group, with time extend, the black rice anthocyanin absorbance all present nonlinear attenuation, and in different storage conditions, the anthocyanin decaying rates present a big difference: strong luminosity > natural light indoor >room temperature in dark>low temperature in dark. In the same storage conditions, the decay rate of non-colored pretection anthocyanin in wine bigger than its counterpart the colored pretection. Using the Mathmatica software, simulating absorbance change with time attenuation law, we gain the equation N（t）=N[αe^-βt+（1-α）e^-γt]. In the condition of keeping wine anthocyanin retentional rate is≥10%, and its actual retentional amount≥0.06, the black rice wine colour is still bright, and showing good commercial values. Taking this condition as technical parameters, calculating and predicting through two-exponential decay equations show : in the dark condition, black wine could storage for 1.8².6 years; in the low temperature condition, black wine could storage for 5.1²1.3 years. This research provide a new evaluated method for both black rice wine selling cycle and the black rice wine anthocyanin stability research. （3） Taking the Heishuai’s anthocyanin as experiment material. Utilizing the analytical column of VARIAN Prostar 210 HPLC, selecting the Sepax GP-C18 column（10.0mm×250mm, 10μm） and in the condition of column temperature 25℃, DAD detector with 520nm detection wavelength, the acetonitrile of mobile phase A is 15%, the phosphoric acid concentration of mobile phase B is 3%, 3-4ml/min flow rate, 5mL linearity. In this condition ,according to the peak appearance with different time orders, we gather 8 Heishuai’s anthocyanin extraction components samples.（4） Using the LC-MS machine analyse the Heishuai’s anthocyanin components, 14 possible anthocyanin components’technology parameters are got. However, with the limition of working conditions,the structures of these 14 possible anthocyanin components are not named and determined in this experiment respectively.