Relationships between antioxidant compounds and antioxidant activities of tartary buckwheat during germination

Relationships of changes between major nonenzymatic antioxidant compounds and antioxidant capacities of tartary buckwheat during germination were evaluated by means of correlation analysis and principal component analysis in this paper. The changes of antioxidant compounds, including vitamin C, vitamin E, flavonoids, carotenoids, and chlorophyll, and antioxidant activities were detected. A good accumulation in the content of vitamin C (0.71 mg/g), total flavonoids (19.53 mg rutin/g), and rutin (11.34 mg/g) was found after 7-day germination, but germination decreased the vitamin E activity. Germination improved the activities of buckwheat extracts to scavenge DPPH, ABTS, and superoxide free radicals by 107, 144, and 88 %, respectively. Furthermore, the correlation and principal component analysis showed that the vitamin C, total flavonoids, and rutin contents were closely related positively with free radicals scavenging properties, indicating that the compounds which play a key role in the elevated antioxidant activities during germination consisted of vitamin C, total flavonoids, and rutin, but not vitamin E and quercetin.