Effects Of Solid-state Fermentation On The Antioxidant Properties Of Purple Wheat Bran

This study screened of strain which collected different sources of white wheat as raw material in flour factory. And this study used the bran of the Shandong Agricultural University self-cultivate purple wheat for material and adopted the method of solid-state fermentation of bran, the release of phenolic acid and antioxidant activity were studied.(1) The screened strains of different sources of branThe study use the different sources of wheat bran from flour factory as material, filtered out the strains which can grow in the ferulic acid ethyl ester and arabinoxylan as the sole carbon source medium can't t grow on ferulic acid as the sole carbon source medium. Screened bacteria 4 strains, yeast 11 strains, mold 13 strains.(2) The screening of best fermentation strainsYeast and mold had the best fermentation effect, ?-Y6 strain of yeast and ?-M11 strain of mold had better phenolic acid release and antioxidant capacity. After the solid-state fermentation of ?-Y6, the total phenolic content and DPPH-scavenging activity of bran were 4.41 mg/g bran and 52.67%,, the total phenolic content and DPPH-scavenging activity after solid-state fermentation used mold IV-Mllwere 3.55 mg/g bran and 51%. In the composition of the phenolic acids, II-Y6 strain's phenolic acids was 3177 ?g/g bran and ?-M11 strain of mold's phenolic acids was 2922 ?g/g bran, and they both give priority to ferulic acid. ?-Y6 of solid-state fermentation's soluble arabinoxylan content of bran was 2.07%, and IV-M11 of solid-state fermentation's soluble arabinoxylan content of bran was 1.76%.(3) The determination of optimum fermentation conditionsBy single factor and orthogonal experiment, this study determined the optimize of the bran solid-state fermentation process:inoculation is 0.8×106cfu/g bran, ratio of material to liquid is 1:0.6, fermentation temperature is 30? and fermentation time is 4 day, and,. After the solid-state fermentation, the total phenol content can reached 4.63 mg GAE/g bran, DPPH-scavenging activity reached 66.54%, ABTS-+ scavenging activity reached 13.06?M Trolox/g bran, the phenolic acids reached 2084.56?g/g bran, and the extraction rate of soluble arabinoxylan reached 3.51%.(4)Determine the type of strainBy the yeast morphological, physiological and biochemical identification tests, the screened fermentation strains is Hansenula.