| 摘要 |
<p>PURPOSE:To obtain SEISHU (refined sake) having reduced urea content, free from coloration and deterioration of flavor and capable of storing for long period, by using a specific and useful SEISHU yeast variant obtained by selecting and separating from yeast obtained by variation treatment of the existing and useful SEISHU yeast. CONSTITUTION:A variant yeast having weak arginine-assimilating ability is selected from canavanine resistant strains obtained by applying variation treatment such as ultraviolet ray irradiation, etc., to an useful yeast for brewing SEISHU. Then fermentation test by one stage charge using alpha-rice and KOJI (Japanese melted rice) is carried out using a large number of the above- mentioned variant yeasts and an useful SEISHU yeast variant having canavanine tolerance, being slow in growth in a culture medium containing arginine as only one nitrogen source and as remarkably small as formation amount of urea in unrefined sake for SEISHU is 1/3 of less of that from parent strain in fermentation process of unrefined sake for SEISHU is selected and separated. Then SEISHU is produced using the resultant variant strain to provide the excellent SEISHU of high quality having remarkably reduced urea content.</p> |
