Quality Characteristics of Seoktanju Fermented by using Different Commercial Nuruks

We investigated quality characteristics of Seoktanju (one of the Korean traditional rice wine) which was fermented using five kinds of Korean commercial Nuruks. The purpose of this study was to research what effects on the quality of Seoktanju by using different Nuruks. We analyzed general component such as each mash's temperature change patterns, pH, titrable acidities, reducing sugar contents, volatile acids, and sugar contents during fermentation periods and studied sensory evaluation of produced Seoktanju (10 days). On the whole, temperature change patterns in the each mashes were depend on room temperature. All Seoktanju's pH was reduced rapidly up to three days after first mashing (pH 3.13-3.57) and after that was increased gradually. The end of fermentation pH was pH 3.6-4.05. Mostly, acidities were indicated high(0.59%) and Nuruk-B was showed highest acid value. These results seems to be different as occasion organic acids producing activity depend on the number of yeast, material contents, optimal temperature in the each mashes by fungi and lactic acid bacteria in Nuruks. In reducing sugar contents and sugar contents, Nuruk-C treatment were showed the highest value with 5.36%, $23^{\circ}brix$, respectively and alcohol content was lowest with 8.6%. In the five kinds of reproduced Seoktanju, alcohol content was the highest in the treated Nuruk-A group. Volatile acid value was the highest with 132.6~263.7 ppm at the 3 day after first mashing day but as the fermentation time goes on, it was reduced sharply by 5.25~5.94 ppm. Sensory evaluation was performed with 5 point scale, the Seoktanju using Nuruk-D was presented by 4 point, while Nuruk-A was presented lowest by 2.77 point on overall acceptability.

시판누룩 사용 별 석탄주의 품질특성

고문헌에 기록된 사라진 우리술을 발굴하는 전통주 복원 프로젝트의 일환으로서 시판 누룩 5종을 사용한 석탄주(惜呑酒)를 제조하여 이들의 양조적성을 구명하였다. 석탄주 발효 중 품온변화 등 일반성분을 분석하였고 완성된 석탄주(발효기간 10일)의 관능평가를 실시하였다. 전체적으로 술덧의 품온변화는 실내온도 변화에 상응하였다. pH는 전체적으로 발효 0~3일차까지 급격히 떨어졌다가 발효 중간부터 완만히 증가(3일: 3.13~3.57, 6일: 3.35~3.80)하였고, 발효 종료 시, pH 3.60~4.05로 상승하였다. 산도는 전반적으로 높았으며 (0.45~0.59%) Nuruk-B의 수치가 가장 높았다. 이는 누룩에 생육하는 유기산 생성 곰팡이와 젖산균이 술덧의 적절한 온도, 원료 조성, 효모 수에 따라 유기산 생산능에 차이가 있는것으로 보여진다. 환원당과 당도는 Nuruk-C로 제조한 석탄주에서 가장 높았으나(5.36%, 23o) 알코올 함량(8.6%)은 가장 낮았다. 5종의 시판누룩으로 발효시킨 석탄주에서 Nuruk-A가 알코올 함량(19.4%)이 가장 높았고 휘발산은 발효 3일째 가장 높은 수치(132.6~263.7 ppm)를 나타내었으나, 발효가 진행되면서 급격히 감소(5.25~5.94 ppm)하였다. 관능평가는 5점 척도법으로 실시하였으며 Nuruk-D로 제조한 석탄주가 전반적인 기호도가 가장 높았고(4.0), Nuruk-A의 경우 가장 낮았다(2.77).