| Buckwheat has high nutritional and pharmaceutical value. Its extensive physiological functions such as reducing blood pressure, blood lipids, blood cholesterol and blood sugar are found to due to its main bioactive ingredients, buckwheat flavonoids and protein extracts. However, buckwheat also has some inherent anti-nutrients, which have key roles in reducing the digestibility of buckwheat proteins. Germination can reduce the content of anti-nutrients of buckwheat or even remove them. Therefore, comprehensive studies including the dynamic changes of main nutrients and bioactive ingredients in buckwheat after germination, the free radical scavenging activities of buckwheat flavonoid and protein extracts, and the protective effects of buckwheat flavonoid and protein extracts on red cell of mice against oxidative damage were carried out. The main results of this paper are as follows.The content of soluble sugar of buckwheat began to increase after 24 h of germination, and could increase to 2.0~3.4 times of its original content after 72 h of germination. There was no obvious change in content of fatty acids. However the content of mono-unsaturated fatty acids (MUFA) increased, while the content of poly-unsaturated fatty acids (PUFA) decreased. Additionally, the content of mineral elements had hardly any change after germination.The method to determine the content of rutin and quercetin in germinated buckwheat by HPLC (high performance liquid chromatography) was developed. The separating column was C-18 reverse phase column. The flowing phase was methanol and water with volume ratio of 50 against 50. The retention time of rutin and quercetin was 3.517 min and 6.303 min at 362 nm of wavelength and 1.0 ml/min of flowing velocity respectively.The content of flavonoids of F.tartaricum Gaerth and F.esculentum Moench reduced slightly and then increased with the time of germination. At 72 h of germination, the content of flavonoids of Sichuan F.tartaricum Gaerth and Shanxi F.esculentum Moench was 33% and 59% higher than its original content (P<0.01) respectively, indicating that the content of buckwheat flavonoids could be raised by prolonging the time of germination. The same situation was also found in the change of the content of rutin during germination. However, the content of quercetin decreased gradually. Making seeds germinate is one of effective methods to reduce the bitterness of buckwheat. During germination, the activity of PAL(Phenylalanine Ammonialyase) took the same situation as the change of flavonoidscontent. Moreover, the PAL activity in F.tartaricum Gaerth was higher than in F.esculentum Moench through the whole period of germination.The total content of protein had hardly any change in F.tartaricum Gaerth and obviously decreased in F.esculentum Moench after germination. In F.tartaricum Gaerth, the content of albumin and globulin was reduced while the content of prolamine and glutelin was raised by germination. In F.esculentum Moench, the content of albumin decreased while the content of other three proteins such as globulin, prolamine, and glutelin increased. The digestibility rate of protein in both F.tartaricum Gaerth and F.esculentum Moench was raised by nearly 10% after germination. The content of TI (Trypsin Inhibitors) was 0.72u/mg and 0.68u/mg in Sichuan F.tartaricum Gaerth and Shanxi F.esculentum Moench respectively. The activity of TI was higher at the early period of germination and was reduced later. For example, the inhibiting rate of TI was 40.8% and 33.4% in Sichuan F.tartaricum Gaerth and Shanxi F.esculentum Moench respectively at 84 h of germination. There was an obvious negative relationship between TI content and protein digestibility.As for amino acids, the content of glutamic acid was the highest through the whole period of germination while the content of arginine and aspartic acid was secondly and thirdly highest respectively. The content of total amino acids increased by 11.2% in F.esculentum Moench but decreased in F.tartaricum Gaerth at 72h of germinatio...
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