| The Black rice is an important functional rice resource in our country. It has strong antioxidation and anti-tumor function due to the rich natural anthocyanin in its seed coat. So it is an important source for the development of natural antioxidants. There are mang varieties of black rice in our country. And the different contents of anthocyanin in different genotypes of black rice is significant.In this study, varieties of black rice from many regions of our country were collected. The genotype differences of anthocyanin content, total flavonoids content and antioxidant capacity were compared and analysed. The antioxidation and anti-tumor ability of black rice were discussed as well.The main results were as following:1. Optimization of extraction processes about the anthocyanin and antioxidative extraction of black rice:The optimum extraction processes of anthocyanin which determined by orthogonal test are: ratio of material and solvent: 1∶100, extract temperature: 40℃, extract time:15h, solvent: 1.5%HCL:methyl alcohol(v∶v). The optimum extraction processes of antioxidative extraction of black rice(AEBR)are ratio of material and solvent: 1∶1 00, extract temperature:80℃, extract time:3h, solvent:80% ethyl alcohol.2. Investigation of the genotype differences of antioxidation of black rice:48 different genotypes of black rice have significant difference in antioxidation. Significant differences in T-AOC,SFRC, total flavonoids content and anthocyanin pigment unit exists among these black rice varieties. And most significant difference exists between T-AOC and the other three indices. In this research, the black rice variety"9A721"with strongest antioxidation is selected. Its T-AOC is 638.78 u / g, 1.5 times of the check variety(CK)"9A751". Its SFRC is 315.2 u / g, 2.1 times of CK. Its total flavonoids content is 5.286 g/100g, 1.4times of CK. Its anthocyanin pigment unit is 30.71, 2.6times of CK. The effect of different years on the antioxidation of black rice is not significant, but seasonal effect is significant. And the antioxidation of late season is significantly higher than that in early season. The antioxidation of black rice and red rice is significantly higher than the white rice.3. Purification of antioxidative extraction of black rice: By comparing the adsorption rate and the desorption rate of 8 kind of macroporous resins on purifying AEBR from black rice , the macroporous resins with best purification effect (NKA-Ⅱ) is selected in this research. 17.5min～67.5min is the best purification time, and the purification effect is up to 81.82%. The anthocyanin pigment unit and T-AOC of purified antioxidative extraction of black rice (PAEBR) are greatly improved after being purified by NKA-Ⅱ. Otherwise, the black rice variety with the highest extraction rate of AEBR is"8B456". Its extraction rate reaches 2.50%.4. Animal experiments about antioxidation in different genotypes of black rice: The animal experiments shows that PAEBR could effectively increase the level of T-AOC,SFRC and T-SOD,and reduce the level of MDA in blood serum and liver of rats. The antioxidant effects and extraction density have a dose effect. However, isodose and different genotypes of PAEBR have no significant effect on the level of T-AOC, SFRC, MDA and T-SOD in blood serum and liver of rats.5. Animal experiments about anti-tumor function in black rice: The animal experiments shows that the highest inhibition rate of PAEBR effects on S180 tumor-bearing rats is up to 32.17%. And the inhibition rate of all groups is related with the dosage present. Both thymus index and spleen index of S180 tumor-bearing rats are obviously enhanced by PAEBR. The thymus index and spleen index of the highest dose group are 2.162mg/g and 5.298mg/g ,enhance 28% and 35% of the endoxan group respectively. These results shows PAEBR could significantly enhance the immunity ability of the S180 tumor-bearing rats.
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