【摘要】 集合超声波、超滤、弱碱性等电点沉淀技术,开发了一种从废弃烟叶中提取可溶性蛋白的新工艺,并构建了一套物理、化学、生物参数评价体系.经优化后的工艺路线如下:在0.085 mol/L磷酸缓冲液(pH=7.85)条件下,以1∶8料液比进行超声波提取,经分级离心、过滤/超滤,并通过0.11 mol/L [H+]溶液调节等电点pH=5.5,成功提取了分子量约为55 kDa及大于200 k Da的混合蛋白,其氨基酸组成分析能满足成人必需氨基酸需求.红外光谱分析未见明显果胶、多糖特征.采用温和弱碱-等电点提取技术结合物理提取方法,有效解决了传统提取方法存在的问题,展现了良好的通用性,为废弃烟叶的资源化利用及工业化生产提供了新的思路.更多还原

【Abstract】 This study innovatively combined ultrasonic extraction, ultrafiltration, and weakly alkaline isoelectric precipitation technologies to devise a process for the efficient extraction of soluble proteins from discarded tobacco leaves. Additionally, a comprehensive evaluation system incorporating physical, chemical, and biological parameters was established. By optimizing the process, an effective protocol was identified as follows. A pH7.85 phosphate buffer at a concentration of 0.085 mol/L was utilized for ultrasonic extraction with a material-to-liquid ratio of 1∶8. Subsequently, fractionated centrifugation and filtration/ultrafiltration were performed, followed by adjustment of the solution to an isoelectric point pH of 5.5 using a 0.11 mol/L [H+] solution. This protocol facilitated the successful extraction of mixed proteins with molecular weights of approximately 55 kDa and exceeding 200 k Da. The amino-acid composition of the extracted proteins satisfied the essential amino-acid requirements of adults. Infrared-spectrum analysis indicated the absence of significant pectin or polysaccharide features. This research introduced a gentle,weakly alkaline isoelectric point extraction approach, combined with physical-extraction techniques. This method not only overcomes the limitations of conventional extraction processes but also exhibits broad applicability. Innovative pathways are presented herein for the resourceful utilization and industrial-scale production of discarded tobacco leaves.更多还原