青稞萌芽富集酚类物质品种筛选及条件优化

Screening of highland barley varieties using phenolics accumulation as indicator and the effect of germination conditions on phenolics

该文旨在研究不同品种萌芽青稞中富集酚类物质含量及萌发条件对于酚类合成的影响,以获得适合萌发富集酚类物质的青稞品种和萌发条件。以产自西藏的6种供试青稞:果洛、喜马拉雅22号、喜马拉雅19号、冬青1号、藏青2000和藏青690为材料,在30℃萌发36 h后,测定其生理生化指标、酚类物质含量及其合成关键酶活力以筛选品种;研究萌芽时间和温度对总酚含量的影响,优化萌发条件。在6个供试品种中,冬青1号的发芽率虽然较低,但是呼吸速率和鲜重最高,说明冬青1号青稞代谢旺盛。同时,该品种中总酚和酚酸含量最高,并且酚类合成酶活性较高,因此确定冬青1号为适合萌发富集酚类物质的青稞品种。冬青1号青稞在萌发24~72 h的过程中,游离酚含量下降,总酚含量组间差异不显著;较低温度下(25~30℃)萌发更有利于酚类物质的累积。响应面优化结果显示,25℃萌发48 h时青稞中总酚含量达到296.72 mg GAE/100 g DW,是原料青稞(201.62 mg GAE/100 g DW)的1.47倍。优选冬青1号青稞品种萌发富集酚类物质,在25℃萌发48 h时青稞中酚类物质含量最高。该研究结果为开发富含酚类物质的藏区萌芽青稞及其功能性产品研发提供理论和数据支撑。

The six highland barley varieties from Tibet,including Guoluo,Himalaya 22,Himalaya 19,Dongqing 1,Zangqing 2000 and Zangqing 690,were used as materials to investigate the accumulation of phenolics in different varieties of germinated highland barley(Qingke)and the germination conditions on the synthesis of phenolics in order to obtain the suitable varieties and germination conditions for the phenolics accumulation.After germination at 30℃for 36 h,the physiological and biochemical indexes,phenolics content and the key enzyme activities were determined to screen the varieties.Then,the effects of germination time and temperature on the content of total phenolics were studied.Among the six tested varieties,although the germination rate of Dongqing 1 was low,the respiration rate and fresh weight were the highest which indicated that the metabolism of Dongqing 1 was vigorous.At the same time,the content of total phenolics and phenolic acids was the highest,and the activity of phenolics synthetase was relatively higher.Therefore,Dongqing 1 was selected as the suitable highland barley variety for accumulating phenolics by germination.During 24-72 h of germination,the content of free phenolics decreased,but the difference of total phenolics content among the germination time points was not significant.The lower the temperature(25-30℃),the more conducive to the accumulation of phenolics.The results of response surface optimization showed that the total phenolics content of highland barley reached 296.72 mg GAE/100g DW after germination at 25℃for 48 h,which was 1.47 times of the raw material(201.62 mg GAE/100g DW).The optimal germination condition of Dongqing 1 highland barley was 25℃for 48 h,and the content of phenolics was the highest.This study provided theoretical and data support for the development of Tibetan pre-germinated highland barley rich in phenolics and its functional products.