匀浆辅助负压空化提取楠竹叶总黄酮及其稳定性研究

Abstract

本研究以楠竹叶为原料，采用匀浆辅助空化的方法萃取总黄酮，对匀浆过程中乙醇体积分数、匀浆时间、料液比以及空化过程中空气流速、空化仪器形状、空化时间等因素，通过单因素试验确定最优参数，并对楠竹叶中总黄酮在光、热、酸碱条件下的稳定性进行研究。结果表明：其最佳的提取条件为：用1:14 g/mL料液比加入70%乙醇溶液匀浆210 s后，再经梨形空化器以空气流速为200 mL/min空化萃取50 min，总黄酮提取率为76.05 mg/g。通过酸碱稳定性分析，竹黄酮在pH值5~7范围内稳定；通过热稳定性分析得知，低于40℃时竹黄酮类化合物稳定，当80℃热降20 h，总黄酮含量从64.32 mg/g降至36.37 mg/g；通过日光及紫外光照射，发现自然光照射20 h，黄酮类化合物含量基本稳定，破坏竹黄酮稳定性的光照次序为UVC > UVB > UVA。研究结果为竹类植物中天然产物开发利用提供了理论依据，对楠竹的综合利用具有指导意义。 In this study, the total flavonoids was extracted from Phyllostachys pubescens leaves by homoge-nate-assisted negative-pressure cavitation method. The volume fraction of alcohol, homogenate time, the solid to liquid ratio, the air velocity, the cavitation equipment shape and cavitation time were optimized by single factor experiment, and the stability of total flavonoids under the condi-tions of light irradiation, being heated, and different pH were studied. The optimum condition for extraction of Phyllostachys pubescens leaves was adding 14 times 70% ethanol solution, homog-enating for 210 s, and then cavitating by the pear shaped instrument at 200 mL/min air velocity for 50 min; the extraction yield of total flavonoids was 76.05 mg/g. Flavonoids extract from Phyl-lostachys pubescens leaves was stable under the pH from 5 - 7; through thermal stability analysis, flavonoids were stable when the temperature was below 40˚C; flavonoids were thermal degraded from 64.32 mg/g to 36.37 mg/g at 80˚C for 20 h; through sunlight and ultraviolet light irradiation stability analysis, when flavonoids was irradiated by natural light for 20 h, the content of flavonoids was basically unchanged, and the effect of light irradiation order was UVC > UVB > UVA. The research results provided theoretical basis for the exploitation and utilization of flavonoids com-pounds in bamboo.