超声处理对石榴皮多酚提取效果的影响

Effects of Ultrasound Treatment on Extraction of Pomegranate Peel Polyphenols

石榴皮是一种易获得的、廉价的,但含有丰富多酚的废料。采用超声辅助提取法从石榴皮中提取多酚,优化工艺参数并利用高效液相色谱法(HPLC)测定石榴皮中多酚的成分和含量,同时研究了石榴皮表面在超声处理下的变化。研究结果表明,在超声条件下,用水作为溶剂有更高的多酚得率,比甲醇等有机溶剂提取效果更好。在优化条件,即液固比(mL∶g)为60∶1,超声功率为400 W和超声时间为25 min时,多酚的最佳得率为39.30 mg/g(以没食子酸为标准),高于传统溶剂提取法的得率(32.58 mg/g)。HPLC分析得到石榴皮多酚中安石榴苷含量最高,其次是石榴皮鞣素,并且超声处理能较大地强化提取效果。石榴皮表面显微观察证明,超声能够显著破坏石榴皮表面而影响植物组织完整性,使多酚更多地释放出来。

Pomegranate peel is an easily available and inexpensive industrial by-product which is rich in polyphenols.In this study,ultrasound-assisted extraction method was used to extract polyphenols from pomegranate peel.The technological parameters were optimized and the composition and content of polyphenols from pomegranate peel were determined by high-performance liquid chromatography(HPLC).The changes of pomegranate peel surface after ultrasonic treatment were also studied.The results showed that with ultrasonic assistant conditions,water as a solvent,had a higher yield of polyphenols,which was better than other organic solvents such as methanol.Therefore,water was used as a solvent for subsequent research.In the optimal conditions of liquid-solid ratio(mL∶g)60∶1,ultrasonic power 400 W and ultrasonic time 25 min,the optimal yield of polyphenols was 39.30 mg/g(using gallic acid as the standard),which was higher than that of conventional solvent extraction method(32.58 mg/g).HPLC analysis showed that the content of punicalagin in pomegranate peel polyphenols was highest,followed by punicalin.Ultrasonic treatment could greatly enhance the extraction effect.The microscopic observation on the surface of pomegranate peel showed that ultrasound could significantly destroy the surface of pomegranate peel and affect the integrity of plant tissue,thus releasing more polyphenols.