title: A new process for preparation of soybean protein concentrate with hexane-aqueous ethanol mixed solvents.
abstract: A new process for the preparation of soybean protein concentrate (SPC) by directly extracting full-fat soy flour with a mixture of hexane and aqueous ethanol was established. Compared with conventional methods, it has some advantages, such as saving energy and reducing protein denaturation caused by heat action during solvent recovery, because this process saves one step of solvent recovery. The effects of aqueous ethanol concentration and the mixure ratio (hexane to ethanol) on the degree of protein denaturation and product quality were investigated, on the basis of which the orthogonal tests were performed. The optimum technical parameters were obtained by analyzing the results of the orthogonal tests with statistical methods. We found that SPC can be obtained by extracting full-fat soy flour under the following conditions: mixture ratio hexane: 90% ethanol, 9:1, v/v; extraction temperature, 45 degrees C; ratio of solid to solvents, (1:2 w/v); and 5 repeated extractions (15 min each time). The results of quality analysis showed that solubility of the product was improved significantly [nitrogen solubility index (NSI) 46.6%] compared with that for ethanol washing of protein concentrate (NSI 8.7%).
authors.affiliation: Wuhan Polytechnic University, Department of Food Science, 430023 Wuhan, People's Republic of China. zhangweinong@163.com
authors.forename: Wei-Nong
authors.initials: WN
authors.lastname: Zhang
authors.forename: Da-Chuan
authors.initials: DC
authors.lastname: Liu
mesh_terms: D000704:Analysis of Variance; D000431:Ethanol / Q000032:analysis*; D005433:Flour; D006586:Hexanes / Q000032:analysis*; D009584:Nitrogen; D010936:Plant Extracts / Q000032:analysis*; D014674:Plant Proteins, Dietary / Q000032:analysis*; D011506:Proteins / Q000032:analysis*; D012997:Solvents; D030262:Soybean Proteins / Q000032:analysis; D013025:Glycine max / Q000378:metabolism*; D014867:Water
chemical_list: D006586:Hexanes; D010936:Plant Extracts; D014674:Plant Proteins, Dietary; D011506:Proteins; D012997:Solvents; D030262:Soybean Proteins; D014867:Water; D000431:Ethanol; D009584:Nitrogen