Department of Food Management, Miyagi University, Sendai, Miyagi, Japan.
Department of Food Management, Miyagi University, Sendai, Japan.
Methods Mol Biol. 2024;2851:125-131. doi: 10.1007/978-1-0716-4096-8_11.
The D-amino acids of D-alanine, D-glutamic acid, and D-aspartic acid increase tasting evaluation scores of Sake, a Japanese traditional alcohol beverage. Sake is brewed using seed mash for growth of brewing yeast without growth of contaminating microorganisms. Kimoto is brewed using lactic acid bacteria growth to decrease pH. Sake brewed using the Kimoto method also has a rich taste and a higher tasting evaluation score than Sake brewed using the Sokujyo Syubo (Moto) method, which adds lactic acid instead of using lactic acid bacteria growth. D-alanine, D-glutamic acid, and D-aspartic acid in Sake have the function of increasing tasting evaluation scores. They are converted by enzymes in lactic acid bacteria respectively as alanine racemase (EC 5.1.1.1), glutamate racemase (EC 5.1.1.3), and aspartate racemase (EC 5.1.1.13) in Kimoto Mash. Herein, simultaneous assay methods for D-alanine, D-glutamic acid, and D-aspartic acid are explained. Sample solutions adjusted to alkalinity are derivatized by an L-FDLA solution only for L-amino acid. Results demonstrate that, for D-alanine, D-glutamic acid, and D-aspartic acid, this method can assay them easily using no expensive or specialized equipment.
D-丙氨酸、D-谷氨酸和 D-天冬氨酸的 D-氨基酸可提高日本传统酒类清酒的品尝评价分数。清酒是用种子醪来酿造的，目的是让酿造用酵母生长，而不让污染微生物生长。生酛则是利用乳酸菌生长来降低 pH 值。用生酛法酿造的清酒味道醇厚，品尝评价分数也高于用速酿法（母曲法）酿造的清酒，因为后者是添加乳酸菌而不是利用乳酸菌生长来降低 pH 值。清酒中的 D-丙氨酸、D-谷氨酸和 D-天冬氨酸具有提高品尝评价分数的作用。它们分别被生酛醪中的酶——丙氨酸消旋酶（EC 5.1.1.1）、谷氨酸消旋酶（EC 5.1.1.3）和天冬氨酸消旋酶（EC 5.1.1.13）转化。本文介绍了用于同时测定 D-丙氨酸、D-谷氨酸和 D-天冬氨酸的方法。将碱性调整后的样品溶液用 L-FDLA 溶液衍生化，仅用于 L-氨基酸。结果表明，对于 D-丙氨酸、D-谷氨酸和 D-天冬氨酸，该方法无需昂贵或专用设备，即可轻松进行测定。
