不同品种啤酒大麦间游离酚类化合物及其相关酶类的研究

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

大麦中的酚类化合物及相关酶（如酚类合成酶苯丙氨酸解氨酶，酚类氧化酶过氧化物酶和多酚氧化酶）对大麦的生长发育、抗病特性及啤酒质量有重要影响。本文研究了16种不同品种、22种不同样本啤酒大麦中酚类物质的含量及相关酶活性的差异性和相关性，并测定了不同品种大麦的抗氧化活力。研究结果表明：不同品种和同一品种不同产地啤酒大麦的酚类化合物含量和酚类酶活性因品种特性和生长、种植条件而存在显著差异（P〈0．05）：游离总多酚含量和抗氧化力之间存在显著的正相关性（r=0．794）：苯丙氨酸解氨酶活性并不与游离总多酚含量呈正相关性．过氧化物酶和多酚氧化酶的活性也不与总多酚含量呈相关性，这可能和大麦中同时存在酶类氧化酶和酚类合成酶有关。研究认为，通过测定大麦游离总多酚含量和DPPH自由基清除率可初步判断啤酒大麦的内源性抗氧化力，以此作为评价酿造原料品质的检测手段。

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 tree 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.