超高压辅助提取山药皮总酚的工艺优化

Optimization for ultrahigh pressure-assisted extraction process of total phenols from yam peel

【目的】优化超高压辅助提取山药皮总酚的工艺条件,为山药皮的开发利用及提高原料利用率提供技术参考。【方法】以山药皮总酚提取率为考察指标,通过比较水浴提取、超声波辅助提取、闪式提取和超高压辅助提取4种方法提取山药皮总酚的效果,选用超高压辅助提取法进行工艺优化,在单因素试验的基础上,采用L9(34)正交试验考察提取时间、超高压压力、乙醇体积分数和料液比对总酚提取率的影响,确定最佳提取工艺条件。【结果】影响超高压辅助提取山药皮总酚的因素排序为:提取时间>超高压压力>料液比>乙醇体积分数,其最佳提取工艺条件为:在乙醇体积分数50%、超高压压力200 MPa、料液比1∶50的条件下提取4 min,山药皮总酚平均提取率为0.424%。【结论】优化后的超高压辅助提取法可明显提高山药皮总酚提取率,且提取时间短、工艺条件稳定,是提取山药皮总酚的有效方法。

【Objective】The extraction process of total phenol from yam peel by ultrahigh pressure extracting method was optimized, in order to provide technical reference for further development and utilization of yam peel and improvement of its utilization ratio. 【Method】Using extraction rate of total phenol from yam peel as evaluation index, the extracting effects of four different extracting methods viz., water-bath extraction method, ultrasonic-assisted extraction method, flash extraction method and ultrahigh pressure-assisted extraction method were compared. Then the ultrahigh pressure-assisted extraction method was chosen to extract total phenol from yam peel. Based on single-factor experiment, L9（34） orthogonal test was conducted to investigate effects of extraction time and pressure, ethanol volume fraction and material-liquid ratio on extracting rate of total phenol, so as to obtain optimal extraction conditions. 【Result】The factors affecting extraction rate of total phenol were ranked, as follows： extraction time〉extraction pressure〉material-liquid ratio〉ethanol volume fraction.And the optimal extraction conditions were ethanol volume fraction of 50%, extraction pressure of 200 MPa, material-liquid ratio of 1 ∶50 and extraction time of 4 min. Under the above optimum conditions, the average extraction rate of total phenol reached up to 0.424%. 【Conclusion】The optimized ultrahigh pressure-assisted extraction method can obviously improve extraction rate of total phenol. Besides, it has some advantages of short extraction time and stable extraction conditions, therefore, which is a effective method for extracting total phenol from yam peel.