The Study Of The Antioxidant Activity In Beer

Flavonoids in beer as active natural products have very strong antioxidation activity, roasting malt as the main raw material of black beer because of its unique baked craft contains rich melanoidins. This paper studies the antioxidation activity of s compounds and melanoidins in beer, evaluation antioxidant contribution of flavonoids compounds and melanoidins in beer. For the development of an antioxidant function beer to provide scientific theory.This research study of three aspects:determination of total flavonoids, melanoidins of Maillard reaction products, dynamic analysis of flavonoids and melanoidin content in the beer during brewing process with there antioxidant activity. The results obtained:1.Determined and compared five methods:spectrophotometric determination of results is higher than the HPLC method of total flavonoids in hops, Al(NO3)3spectrophotometric determination has the result over the HPLC method measured4times; AICl3spectrophotometry by HPLC determination results closer to the content measured by HPLC1.9times; the SBC method the results obtained by HPLC8.2times; and the hydrolysis-HPLC method to measure the total flavonoids content was more than6.8%to HPLC method. The AICl3spectrophotometric method is a simple, low-cost method suitable for determination of hops and beer total flavonoids.2. The content of melanoidins with different roasting process conditions are as follows:reaction content of melanoidins with temperature120℃time10,30,85min were14.88,18.82.20.67mg/mL; temperature150℃time10,30,85min were16.94.21.10,11.23mg/mL; temperature180℃time10,30,85min were10.58,9.619,3.32mg/mL. The best roast malt process is150℃30min.Malt melanoidins on DNA results show that the malt melanoidins concentration of12mg/mL has significant protection, malt melanoidins concentration of37.5mg/mL effect reaches the maximum, indicating that malt melanoidins plays the role of inhibit oxidative DNA damage. Malt melanoidins macroporous resin separation test results indicate that the smaller polarity malt melanoidins components has stronger antioxidant activity; dextran gel column chromatography separation of malt melanoidins indicate that the smaller molecular weight melanoidins shows stronger anti-oxidizing power. 3. Results show that flavonoids in various stages of the beer brewed has effect on DPPH radical scavenging activity, the correlation analysis results show that the total flavonoids content of beer has strong antioxidant capacity. Total flavonoids on DPPH scavenging rate on the0.01level (bilateral) was significantly associated.Black beer shows strong antioxidant capacity during brewing process. DPPH radicals, hydroxyl radical scavenging ability and reducing power is also increasing with the extension of the brewing time and the melanoidin content gradually increased.Melanoidins content duing various stages of DPPH, hydroxyl radical scavenging and reducing power at the0.01level (bilateral) was significantly related. The results showed that flavonoids and melanoidins in beer brewing process to play major roles in antioxidant capacity...