Cookman Drew J, Glatz Charles E
Department of Chemical and Biological Engineering, Iowa State University, 2114 Sweeney Hall, Ames, IA 50011, USA.
Bioresour Technol. 2009 Mar;100(6):2012-7. doi: 10.1016/j.biortech.2008.09.059. Epub 2008 Nov 22.
We have investigated the feasibility of extracting the oil and protein from distiller's grain (DG) to obtain a higher-valued protein-rich product and a carbohydrate-rich residue better suited for conversion to fermentable sugars. Protein extractions based on aqueous ethanol, alkaline-ethanol, and aqueous enzyme treatments were compared. Three of the methods extracted a significant amount of the protein from dried, defatted DG (DDDG). The enzymatic extraction decreased the crude protein content in the solid phase for both milled and unmilled DDDG from 41% (dry weight) to approximately 10% (dry weight) protein in the residual solid; this corresponded to extraction of 90% of the protein in the original DDDG. The alkaline-ethanol extraction was similarly effective for milled but not unmilled DG. Simple extraction with alcohol was not as effective. Amino acid analysis of each protein extract was consistent with it consisting mainly of zeins. For the protease-assisted extractions, 95% the proteins were in the form of peptides smaller than 10kDa.
我们研究了从酒糟（DG）中提取油脂和蛋白质以获得更高价值的富含蛋白质产品以及更适合转化为可发酵糖的富含碳水化合物残渣的可行性。比较了基于乙醇水溶液、碱性乙醇和酶水溶液处理的蛋白质提取方法。其中三种方法从干燥、脱脂酒糟（DDDG）中提取了大量蛋白质。酶提取使研磨和未研磨的DDDG固相中的粗蛋白含量从41%（干重）降至残留固体中约10%（干重）的蛋白质；这相当于提取了原始DDDG中90%的蛋白质。碱性乙醇提取对研磨后的DG同样有效，但对未研磨的DG无效。单纯用酒精提取效果不佳。对每种蛋白质提取物的氨基酸分析表明，其主要由玉米醇溶蛋白组成。对于蛋白酶辅助提取，95%的蛋白质为小于10kDa的肽形式。
