废弃烟叶可溶性蛋白的提取工艺

Extraction process of soluble proteins from discarded tobacco leaves

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 kDa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.

This study innovatively combined ultrasonic extraction,ultrafiltration,and weakly alkaline isoelectric precipitation technologies to devise a process for the efficient ex-traction 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 pH 7.85 phosphate buffer at a concentration of 0.085 mol/L was utilized for ultrasonic ex-traction with a material-to-liquid ratio of 1∶8.Subsequently,fractionated centrifugation andfiltration/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 kDa.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.