5 mass % including the arginine above vis-a-vis all the solid amounts, the yeast extract constituent which becomes is disclosed. This kind of yeast extract constituent, it possesses arginine analog tolerance, at the same time, with the nutrient medium which designates the arginine as the only nitrogen source it does not grow, but it is produced ideally by the yeast which with the nutrient medium which designates ornithine as the only nitrogen source possesses growth possible character, belongs to the Saccharomyces. As for the yeast extract constituent which relates it is possible to use for ideal, as a flavor revised medicine of the eating and drinking item.全固形分に対して5質量%以上のアルギニンを含んでなる酵母エキス組成物が開示される。このような酵母エキス組成物は、アルギニンアナログ耐性を有し、かつ、アルギニンを唯一の窒素源とする培地では生育しないが、オルニチンを唯一の窒素源とする培地では生育可能な性質を有する、サッカロミセス属に属する酵母によって好適に製造される。係る酵母エキス組成物は飲食品の風味改良剤として好適に用いることができる。
