采用国标方法分别对7种市售甜面酱样品的水分、粗脂肪、总氮和粗蛋白的含量进行了测定，利用氨基酸自动分析仪、高效液相色谱仪分别对甜面酱中的游离氨基酸及核苷酸含量进行了测定，利用凝胶色谱柱对甜面酱中小分子肽的分子量分布进行了测定，同时分析计算了甜面酱的水解度、平均肽链长度和氨基酸味道强度值，及其对呈味的贡献。研究结果表明：7种市售甜面酱的水分、粗脂肪、总氮和粗蛋白等平均含量分别为51.42%，1.84%，1.284%和7.32%；甜面酱中游离氨基酸总含量为1.55~2.78 g/100 g，含量相对较高的为脯氨酸、谷氨酸、亮氨酸、天门冬氨酸，其中谷氨酸的味道强度值（TAV值）最高（7.00~25.67），对鲜味具有重要的贡献；甜面酱中的核苷酸主要为次黄嘌呤（3.19~4.87 mg/100 g），但其TAV值均小于0.5，对甜面酱的滋味没有直接影响；甜面酱中小分子肽的含量为0.55~3.31 g/100 g，平均肽链长度为2~4，分子量主要分布于221~445 u之间，且对鲜味具有一定的贡献。

The methods described in GB/T were used to measure the moisture, crude fat, total nitrogen, and crude protein contents in seven commercially available samples of sweet bean sauce. An automatic amino acid analyzer and high performance liquid chromatography were employed to analyze the free amino acids and nucleotides in the sweet bean sauces, respectively. The molecular weight distribution of small peptides in the sweet bean sauces was determined by size exclusion chromatography (SEC), and the degree of hydrolysis, average peptide chain length, and taste activity value (TAV) of amino acids in sweet bean sauce, as well as their contributions to the taste were calculated and analyzed. The experimental results showed that the moisture, crude fat, total nitrogen, and crude protein contents in seven commercially available samples of sweet bean sauce were 51.42%, 1.84%, 1.284%, and 7.32%, respectively. The total free amino acid contents in the seven pastes ranged from 1.55~2.78 g/100 g, and the most abundant amino acids were proline, glutamic acid, leucine, and aspartic acid. Among them, glutamic acid had the highest TAV (7.00-25.67) and had an important contribution to the taste of umami. Hypoxanthine (Hx) was the dominant nucleotide in sweet bean sauce (3.19~4.87 mg/100 g), but did not have a direct impact on the taste (TAV < 0.5). The small peptide content in sweet bean sauce was in the range of 0.55~3.31 g/100 g; the average peptide chain length (PCL) was between 2 and 4, and the molecular weight distribution was in the range of 221~445 u. Additionally, these small peptides contributed to the taste of umami to some extent.

国家自然科学青年基金（31101350）；北京市属高等学校高层次人才引进与培养计划项目（CIT&TCD201404034）；2012年北京市新世纪百千万人才工程培养经费资助项目（19000550064）