本文以酱油上清液为对照，以过滤-冷冻真空干燥法制备了酱油渣。首先，对比研究了酱油渣的常规理化指标。其次，以SDS-PAGE、MALDI-TOF/TOF MS和HPLC法对酱油渣和酱油上清中蛋白质分子量分布、来源与种类及氨基酸组成特征进行了研究。结果显示酱油渣（湿渣）主要由15.98%的碳水化合物、10.19%的蛋白质、10.10%的食盐和59.50%的水分组成。SDS-PAGE和MALDI-TOF/TOF MS分析结果显示酱油渣蛋白质主要由分子量约为19.3 kDa（a, 59.40%）、31.8 kDa（b, 12.91%）和12.3 kDa（c, 27.69%）的蛋白质亚基组成，经质谱鉴定分子量为19.3 kDa的多肽（a）为Glycinin G4亚基碱性端B3。酱油渣蛋白质氨基酸组成分析表明，与酱油上清中蛋白质相比，酱油渣蛋白质中疏水性氨基酸含量和平均疏水值明显高于酱油上清中蛋白质。上述差异是酱油渣蛋白质氨基酸组成的主要特征，也是酱油渣蛋白质水溶性差和形成的主要原因。

In this paper, the soy sauce residue was prepared by filtration-lyophilization, and the supernatant of soy sauce was used as control. The proximate indices of soy sauce residue were comparatively analyzed. The molecular weight distribution, variety and source and characteristics of amino acid composition of proteins in soy sauce residue and the supernatant were investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), matrix-assisted laser desorption ionisation-time of flight/time of flight mass spectrometry (MALDI-TOF/TOF MS) and high-performance liquid chromatography (HPLC). Results showed that soy sauce residue (wet) was mainly composed of carbohydrate (15.98%), proteins (10.19%), NaCl (10.10%) and water (59.50%). Analysis of SDS-PAGE and MALDI-TOF/TOF MS results demonstrated that proteins in soy sauce residue primary consisted of molecular weights of 19.3 kDa (a, 59.40%), 31.8 kDa (b, 12.91%) and 12.3 kDa (c, 27.69%) subunits, and proteins with molecular weights of 19.3 kDa (a) was identified as the basic polypeptide B3 of soy glycinin G4. Research on amino acid composition indicated the hydrophobic amino acid content and the average hydrophobicity of proteins in soy sauce residue were significantly higher than those in the supernatant proteins. The differences were the chief characteristics in amino acid composition of proteins in soy sauce residue, and could explain the low solubility and formation of soy sauce residue proteins.

江南大学2011年校自主科研计划项目（JUSRP111A26），江南大学工业生物技术教育部重点实验室开放课题（KLIB-KF201108），江苏高校优势学科建设工程资助项目