基于提取温度控制与辅料优化的山药提取物溶化性改善策略研究

Research on the Improvement Strategy of the Solubility of Dioscoreae Rhizoma Extract Based on Extraction Temperature Control and Excipient Optimization

关键词:  山药  提取工艺  溶化性  淀粉  糊化温度  小分子糖  多糖

Key words:  Dioscoreae rhizoma  extraction process  solubility  starch  gelatinization temperature  small molecule sugar  polysaccharide

摘要:

目的 通过优化山药饮片提取温度，减少淀粉溶出，延缓淀粉糊化进程，并探究辅料(小分子糖)添加对改善山药提取物及其配方颗粒溶化性的作用。方法 采用差示扫描量热法(DSC)确定山药淀粉糊化温度范围，并分析不同添加量的小分子糖(乳糖和葡萄糖)对山药淀粉糊化性质的影响。基于山药淀粉糊化温度优化山药饮片提取温度，分别采用回流提取(常规提取方式)、100 ℃水浴浸提、90 ℃水浴浸提、80 ℃水浴浸提、70 ℃水浴浸提5种方法制备山药提取物并对各提取物的溶化性进行分析，同时考察存在温度差异的5种提取方法对山药提取物的特征图谱、出膏率、尿囊素与腺苷含量及转移率、多糖与淀粉含量的影响。此外，在90 ℃、80 ℃和70 ℃提取或浓缩阶段添加20%乳糖，验证乳糖对溶化性及有效成分转移率的影响。结果 DSC结果显示山药淀粉起始糊化温度为73.97 ℃，峰值糊化温度为82.28 ℃，添加不同含量的乳糖和葡萄糖均可提高山药淀粉的糊化温度，乳糖(20%)效果最为明显。4种水浴浸提制备的山药提取物的溶化性随温度的降低呈上升趋势，与回流提取及100 ℃水浴浸提相比，90 ℃、80 ℃、70 ℃水浴浸提均能显著改善山药提取物的溶化性。5种提取方法制备的山药提取物的指纹图谱无明显差异，表明其质量稳定。相比于回流提取及100 ℃水浴浸提，80 ℃水浴浸提的山药提取物的尿囊素、腺苷含量及其转移率最高，90 ℃次之；4种水浴浸提制备的山药提取物中的多糖及淀粉含量随温度的降低呈下降趋势，其中80 ℃、70 ℃水浴浸提显著减少了山药提取物中多糖含量。乳糖添加验证实验结果显示，在提取或浓缩阶段添加20%乳糖，对尿囊素和腺苷转移率无显著影响，且能显著改善90 ℃、80 ℃和70 ℃提取物的溶化性。结论 采用80 ℃~90 ℃水浴浸提法制备山药提取物，并在提取或浓缩阶段添加乳糖(20%)均可在保障有效成分溶出的同时，显著改善山药提取物的溶化性，为山药提取工艺的改进提供数据支撑，为山药配方颗粒溶化性的改善提供理论依据。

Abstract:

OBJECTIVE To reduce starch leaching and delay the starch pasting process by optimizing the extraction temperature of Dioscoreae rhizoma pieces and to investigate the role of excipient (small molecular sugar) addition in improving the solubility of Dioscoreae rhizoma extract and its formulated granules. METHODS Differential scanning calorimetry (DSC) was used to determine the temperature range of Dioscoreae rhizoma starch pasting and to analyze the effects of different added amounts of small molecular sugars (lactose and glucose) on the pasting properties of Dioscoreae rhizoma starch. Based on the optimization of the extraction temperature of Dioscoreae rhizoma starch pasting temperature of Dioscoreae rhizoma pieces, five methods of reflux extraction (conventional extraction method), 100 ℃ water bath extraction, 90 ℃ water bath extraction, 80 ℃ water bath extraction, 70 ℃ water bath extraction were used to prepare the Dioscoreae rhizoma extracts and analyze the solubility of each extract, and at the same time, to examine the existence of temperature differences in the five methods of extraction on the Dioscoreae rhizoma extracts of the characteristics of the mapping, the rate of paste, allantoin and adenosine content and transfer rate, polysaccharide and starch content. In addition, 20% lactose was added at 90 ℃, 80 ℃ and 70 ℃ during the extraction and concentration stages to verify the effects of lactose on solubility and transfer rate of active ingredients. RESULTS The DSC results showed that the onset pasting temperature of Dioscoreae rhizoma starch was 73.97 ℃, and the peak pasting temperature was 82.28 ℃. The addition of different contents of lactose and glucose could improve the pasting temperature of Dioscoreae rhizoma starch, and lactose (20%) had the most obvious effect. The solubility of the Dioscoreae rhizoma extracts prepared by the four water bath extractions showed an increasing trend with the decrease of temperature, and compared with the reflux extraction and 100 ℃ water bath extraction, 90 ℃, 80 ℃, and 70 ℃ water bath extracts were able to improve the solubility of the Dioscoreae rhizoma extracts significantly. The fingerprints of the Dioscoreae rhizoma extracts prepared by the five extraction methods showed no significant difference, indicating that their quality was stable. Compared with the reflux extraction and 100 ℃ water bath extraction, the Dioscoreae rhizoma extracts extracted by 80 ℃ water bath extraction had the highest allantoin and adenosine contents and their transfer rates, followed by 90 ℃. The polysaccharide and starch contents of the Dioscoreae rhizoma extracts prepared by the four water bath extraction methods showed a decreasing tendency with decreasing temperatures, and among them, the polysaccharide contents of Dioscoreae rhizoma extracts were significantly reduced by the 80 ℃ and 70 ℃ water bath extraction. The results of lactose addition validation experiments showed that the addition of 20% lactose at the extraction or concentration stage had no significant effect on the allantoin and adenosine transfer rates and significantly improved the solubility of the extracts at 90 ℃, 80 ℃ and 70 ℃. CONCLUSION Using 80 ℃~90 ℃ water bath extraction method to prepare Dioscoreae rhizoma extracts, and adding lactose (20%) in the extraction or concentration stage can significantly improve the solubility of Dioscoreae rhizoma extracts while guaranteeing the dissolution of active ingredients, providing data support for the improvement of the extraction process of Dioscoreae rhizoma, and theoretical basis for the improvement of the solubility of the Dioscoreae rhizoma formulated particles.