Characteristics of a Modified Nuruk Made by Inoculation of Traditional Nuruk Microorganisms

전통 누룩미생물들로 제조한 개량누룩의 특성

In order to improve the quality of nuruk a Korean traditional fermenting agent for brewing nuruk was modified by a new method inoculating Rhizopus japonicus T2 Aspergillus oryzae L2 and hansenula sp. BC26 which had been isolated from traditional Nuruk. And the characteristics of modified Nuruk were investimgated as compared with current fermenting agents such as commercial Nuruk and rice koji of As-pergillus kawachii. The odor of modified Nuruk was savory but those of commercial Nuruk and rice koji were fetid andinodorous repectively. The extracted waters of modified Nuruk commercial Nuruk and rice koji were yellow pale yellow and colorless and showed 6.15, 6.01 and 3.30 of pH respectively. Mod-ified Nuruk had 7.6${\times}$106CFU/g of yeast but commercial uruk and rice koji had no yeast. Commercial Nuruk had 1.0${\times}$102CFU/g of lactic acid bacteria but modified Nuruk and rice koji had no lactic acid bacteria. The amylolytic and proteolytic activities of modified Nuruk were much higher than those of commercial Nuruk or rice koji. Seed mash of modified Nuruk had ester aroma but that of commercial Nuruk rather offensive odor and that of rice koji neither ester aroma or offensive odor. It seemed that if the modified Nuruk is used in seed mashing the supplement of acidulant is need to lower pH. The quality of modified Nuruk was thought to be much better than that of commercial Nuruk or rice koji.