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In this experiment, 15 different grain color type P. miliaceum shell powder as test materials using single factor experiment and response surface methodology to investigate the the polyphenols extraction method of the the P. miliaceum shell powder laboratory; and compare different grain color corn millet varieties shell powder in polyphenol content and antioxidant activity (DPPH method, beta-carotene - linoleic acid emulsion law and the ABTS law), and phenolic acids and flavonoids substances composed. The results are as follows: (1) Common Millet shell polyphenols extracted optimum conditions for acetone concentration of 90%, solid-liquid ratio 1:30 (g / mL), five times the number of extraction. The polyphenols in optimum conditions, the rate of 1.46%. (2) Millet Cultivars and colors more shallow, the higher the L * value of the shell powder; the Millet particles closer the color red, the a * value is greater. The total phenol content in the corn millet husk powder the the 935.73 ~ 1909.29mg GA eq/100gDW, wheat bran polyphenol content of 3 to 6 times, and combined phenol forms exist. Corn millet grain color is the deeper, higher free phenol content and free flavonoid content; the P. miliaceum shell total flavonoid content of the powder range of 24.79 ~ 68.24 mg Rutin eq/100gDW shell powder; and mainly exists in the form of free flavonoids, Millet the deeper shell color, its free phenol content of free flavonoid content; different colors of corn millet husk powder free phenolic extract DPPH · scavenging, ABTS · scavenging AAC value of the order is: brown varieties gt; red varieties gt; gray varieties gt; white varieties; L *, b *, the results of DPPH · scavenging ABTS · scavenging results with corn millet shell polyphenols content was significantly correlated indicate that polyphenols are formed between different corn millet varieties grain color important differences and antioxidant activity of different reasons. (3) is detected in the free phenolic extract in the of Millet shell powder 9 polyphenolic component, wherein the gallic acid is unique in the free phenolic extract, but mainly of polyphenols are catechins, the content was 0.49 ~ 1.41mg / g, followed by p-coumaric acid, chlorogenic acid, ferulic acid, protocatechuic acid, rutin, quercetin and homovanillic acid; combined phenol extract polyphenols than the free phenol extraction Enrichment was detected by the 10 kinds of polyphenols, wherein the caffeic acid is unique to, and the content is very low, the main polyphenol catechins and p-coumaric acid, the content is 0.38 to 1.50 mg / g and 0.02 ~ 1.20mg / g, followed by chlorogenic acid, protocatechuic, syringic acid, ferulic acid, rutin, quercetin and homovanillic acid.
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