Researsh Of Phenols And Antioxidant In Malt

Beer has become an important popular beverage. With the development of the beer brewing industry matures, more pursuit of flavor and taste of the beer. As main raw material of brewing, malt plays a vital role on the quality of beer. This paper set out from malting barley to produce malt for the target with high antioxidant, studies on the effect that malting conditions to antioxidation capacity of malt. Hope that by increasing the antioxidant capacity of malt to provide a reference for solving issues such as non-biological stability and beer flavor stability.This paper mainly studies the antioxidant effects of phenolic compounds. Determination of phenolic compounds including ferric ammonium citrate method for total polyphenol, high performance liquid chromatography method for ten kinds of monophenol for gallic acid, ferulic acid, catechin, epicatechin, τ-coumarin, caffeic acid, protocatechuic acid, syringic acid, sinapic acid, quercetin. Evaluation of antioxidant capacity are DPPH radical scavenging activity, ABTS radical scavenging activity and reducing power.To measure total polyphenol content, ten monophenol content and antioxidant capacity in Baudin、 Buloke、Gairdner、Vlamingh、Hindmarsh、Metcalfe、Guochan seven varieties of barley and malt. Results showed that between different varieties of barley and malt total polyphenol content and antioxidant capacity are different. The antioxidant of malt mostly than its in barley. In barley and malt has the highest content of catechin, quercetin lowest. The content of quercetin in malt is less than in barley, protocatechuic acid and τ-coumarin has a slight decrease and others have a varying degrees of increase. Analysis showed that total polyphenol content and antioxidant capacity has significant correlation, especially for the DPPH radical scavenging activity. Catechin has significant correlation with DPPH radical scavenging activity, ABTS radical scavenging activity and reducing power, so its antioxidant role in the strongest.Study on Metcalfe、Gairdner、Guochan three kinds of barley in the malting process of changes of phenolic compounds and antioxidant capacity. After steeping, total polyphenol content and antioxidant indicators results reduced; germination period, total polyphenol and DPPH radical scavenging activity fluctuated significantly, ABTS radical scavenging activity and reducing power appears as a continuing rise; in the drying phase, total polyphenols, DPPH radical scavenging activity and reducing power increased significantly, ABTS radical scavenging activity decreased. Ultimately, total polyphenol and antioxidative activity of the malt than the original barley has improved. Overall, Metcalfe malts has the best most total polyphenol content and antioxidant power. Changes of ten types of monophenol in the malting process is not exactly the same, some even showed the opposite result. Steeping make the majority of monophenol content reduced. Generally increasing trend during the germination. In drying phase, ferulic acid, epicatechin, catechin, caffeic acid, gallic acid, protocatechuic acid large increase and other monophenol decreased.To optimization of the malting process, including steeping, germination temperature, kilning temperature, kilning time. Identified the optimum condition for preparation of Gairdner malt with high antioxidant capacity is steep7off17, germination temperature at15-16-17-18℃, kilning85℃3h.