Taste active components of fish sauces

测定了东南亚7国鱼露中游离氨基酸、有机酸、核苷和碱基、糖、肌酸和肌酐等呈味物质的含量，以评价其呈味特征。越南、日本和泰国的鱼露中富含这些化合物，氨基酸组成也十分相似。另一方面，缅甸和老挝的鱼露含有非常少量的这些化合物，并显示出不同的氨基酸模式。中国和韩国的鱼露则介于这两个极端之间。以沙丁鱼和鱿鱼的肌肉和内脏为原料，分别用10%和20%的氯化钠进行为期半年和一年的发酵，研究了酱料发酵过程中肌酸的产生及其对鱼露质量的影响。在发酵过程中测定了上述各种化合物。20%盐制剂的游离氨基酸总量在5个月后达到峰值，此后略有下降。10%盐制剂在3个月后达到最大值，且大于20%盐制剂。这些结果表明，由微生物发酵占主导地位，在10%的盐制备。在一个典型的越南酱料，合成提取物制备和味道活性成分的感官分析，使用省略和添加测试确定。在上述各种化合物中，发现谷氨酸、苏氨酸、丙氨酸、缬氨酸、组氨酸、脯氨酸、酪氨酸、胱氨酸、甲硫氨酸和焦谷氨酸是味道活性组分。在肽组分中，中性和碱性组分增强了合成提取物的甜味，酸性组分使合成提取物具有酸味。

Free amino acids, organic acids, nucleosides and bases, sugars, creatine and creatinine were determined to evaluate the feature of taste components in fish sauces produced in the seven countries of Southeast and East Asia. Fish sauces from Vietnam, Japan, and Thailand were rich in these compounds and showed rather similar amino acid pattern. Myanmar and Laos fish sauces, on the other hand, contained very small amounts of these compounds and showed different amino acid pattern. Chinese and Korean fish sauces fell into the intermediate between these two extremes. Creatinine which originates from creatine during fish sauce fermentation and receives only small bacterial decomposition is a possible marker for the quality control in fish sauce factories.The muscle and viscera of sardine and squid were fermented with 10 or 20% sodium chloride for a half year and a year, respectively. The above mentioned various compounds were determined during fermentation. Total free amino acid of 20% salt-preparation reached a peak after 5 months and declined a little after that. That of 10% salt-preparation reached a peak after 3 months and was larger in amount than that of 20% salt-preparation. These results suggest that fermentation by microorganisms was predominant in 10% salt-preparation.On a typical Vietnamese fish sauce, synthetic extracts were prepared and taste active components were determined by sensory analyses using omission and addition tests. Of the various compounds mentioned above, glutamic acid, threonine, alanine, valine, histidine, proline, tyrosine, cystine, methionine, and pyroglutamic acid were found to be taste active components. In peptide fractions, neutral and basic fraction enhanced sweet taste of the systhetic extract and acidic fraction gave sour taste.