Study on the Free Phenolic Compounds and Related Enzymes in Different Malting Barley(Hordeum vulgare L.) Varieties

The growth and anti-infection of barley,and quality of beer were influenced by the content of phenolic compounds and related enzymes(such as,phenylalanine ammonia lyase,PAL;peroxidase,POD and polyphenol oxidase,PPO).In the present study,the differences and correlations of free phenolic compounds and related enzymes,and the antioxidant activity of 22 samples which were composed of 16 different malting barley(Hordeum Vulgare L.) varieties were investigated.The results indicated that free phenolic compounds and related enzymes activity in different barley had significant difference due to the different variety characteristics and cultivated conditions.The significant positive correlation was found between free phenolic content and antioxidant activity(r=0.794),while there was no significant correlation between free phenolic content and phenylalanine ammonia lyase activity,as well as peroxidase activity and polyphenol oxidase activity,which may due to the fact that there were certain phenolic oxidase and biosynthesizing enzymes in barley.It may be concluded that endogenesis antioxidant activity of malting barley can be evaluated by the determination of free phenolic compounds and DPPH radical scavenging capacity.