Abstract
In this study, 0, 20, 40, 60, 80, and 100% $Ulmus$ $pumila$ L. nonglutinous and glutinous sikhe were added to $Ulmus$ $pumila$ L. extracts for 15 days at $4^{\circ}C$, and for seven days at $25^{\circ}C$, to examine the extracts' storage properties and sensory characteristics. The results are as follows: (1) On the changes of pH and acidity during storage of $Ulmus$ $pumila$ L. nonglutinous and glutinous sikhe, both of them showed lower pH values with lower additive $Ulmus$ $pumila$ L. extract contents. The pH value continuously decreased with a longer storage period, and the acidity was higher with a lower concentration of $Ulmus$ $pumila$ L. extract. (2) The total microbial cell count during storage of $Ulmus$ $pumila$ L. nonglutinous and glutinous sikhe at $4^{\circ}C$ was 4.6-5.0 log CFU/g at 0 day. The sikhe to which $Ulmus$ $pumila$ L. extract was not added increased to 8.8-9.0 log CFU/g on the seventh storage day, while the sikhye to which 80 and 100% $Ulmus$ $pumila$ L. extracts were added were 7.8 and 6.9 logCFU/g, respectively. Thus, the total cell count was lower with a higher additive content of $Ulmus$ $pumila$ L. extract. The total cell count of the sikhe to which 0-60% $Ulmus$ $pumila$ L. extracts reached the maximum value on the seventh storage day and did not show any change thereafter. The total cell count of the sikhe to which 80 and 100% $Ulmus$ $pumila$ L. extracts were added, however, reached the maximum value on the 10th to 13th storage days, thus showing that the storage period was increased by $Ulmus$ $pumila$ L. At $25^{\circ}C$, the total cell count was 4.6-5.0 log CFU/g on 0 day and continuously increased during the storage period. It had increased to 8.9-9.5 log CFU/g on the seventh storage day, and no differences were shown according to the additive content of $Ulmus$ $pumila$ L. extract. (3) On the sensory characteristics of $Ulmus$ $pumila$ L. nonglutinous and glutinous sikhe, the $Ulmus$ $pumila$ L. nonglutinous sikhe to which 20% $Ulmus$ $pumila$ L. extract was added showed the highest overall-acceptability value ($4.23{\pm}0.95$), whereas the $Ulmus$ $pumila$ L. glutinous sikhe to which 40% $Ulmus$ $pumila$ L. extract was added showed the highest overall-acceptability value ($3.95{\pm}0.95$). The sikhe to which 20 and 40% $Ulmus$ $pumila$ L. extracts were added showed significantly high taste, flavor, sweetness, and overall-preference values (p<0.05).
본 연구는 유근피 물 추출물을 각각 0%, 20%, 40%, 60%, 80%, 100% 첨가한 유근피 멥쌀식혜 및 찹쌀식혜의 $4^{\circ}C$에서 15일간, $25^{\circ}C$에서 7일간 저장하면서 저장성 및 관능 특성을 검토하였으며 그 결과는 다음과 같다. 유근피 멥쌀식혜 및 찹쌀식혜의 저장 중 pH 및 산도변화는 유근피 추출물의 첨가량이 적을수록 pH가 낮았고 산도는 높았으며, 저장 기간이 길어질수록 계속 pH는 저하되었고 산도는 높아졌다. 유근피 멥쌀식혜와 찹쌀식혜의 저장 중 총균수는 $4^{\circ}C$의 경우 제조 당일의 균수는 4.6~5.0 Log CFU/g이었으며 저장 7일까지 0%첨가구의 경우 8.8~9.0 Log CFU/g까지 증가하였으나 유근피추출물 80% 및 100% 첨가한 경우는 7.8 Log CFU/g 및 6.9 Log CFU/g로 유근피 추출물의 첨가량이 많을수록 총균수 증가가 적었다. 0%~60% 유근피 첨가식혜의 경우 저장기간 7일 까지 총균수가 최대에 도달하여 그 이후로는 변화가 없었으나 80% 및 100% 첨가구의 경우는 10~13일에 균수가 최대에 도달하는 결과로 유근피에 의하여 저장기간이 연장됨을 알 수 있었다. $25^{\circ}C$의 경우 총균수는 제조 당일 4.6~5.0 Log CFU/g에서 저장기간동안 계속 균수가 증가하여 저장 7일째에는 8.9~9.5 Log CFU/g까지 늘어났으며 유근피 추출물의 첨가량에 따른 차이는 없었다. 유근피 멥쌀식혜 및 찹쌀식혜의 관능적 특성은 유근피 멥쌀식혜는 전체적인 기호도에서 20%첨가구가 $4.23{\pm}0.95$로 가장 높았으며, 유근피 찹쌀식혜는 전체적인 기호도에서 40% 첨가구가 $3.95{\pm}0.95$로 가장 높았다. 20%, 40%의 유근피추출액을 함유한 식혜에서 맛, 향, 단맛, 종합적 기호도에서 유의적으로 높은 값을 보였다(p<0.05).
