본 연구는 다양하고 우수한 약리활성을 가진 도토리를 이용하여 도토리 분말의 첨가비율을 쌀가루 대비 0, 5, 10, 15, 20%로 달리하여 도토리 설기떡을 제조한 후, 도토리 설기떡의 이화학적 특성과 저장기간에 따른 품질특성, 도토리 설기떡 열수 및 에탄올 추출물의 항산화 효과 등의 연구를 통하여 도토리 설기떡의 기능성 향상과 더불어 도토리에 식품소재로서의 활용도를 높이는데 기초자료로 활용하고자 하였다.
1. 도토리 설기떡의 이화학적 특성을 분석한 결과 일반성분의 수분함량은 40.15~44.42%로 도토리 분말의 첨가량이 증가할수록 증가하였고, 조지방, 조회분 함량도 증가함을 보였으며, 탄수화물 및 조단백질의 함량은 도토리 분말 첨가량이 증가할수록 감소하였다. pH는 2.54~5.61으로 도토리 분말의 첨가량이 많을수록 낮아짐을 보이고, 당도는 1.17~1.74 °Brix으로 도토리 분말의 첨가량이 많을수록 다소 낮아지는 경향을 보였으나 유의적인 차이는 없었다. 수용성 단백질 함량은 0.10~0.81 g/100 g으로 도토리 분말 무첨가군에 비해 도토리 분말 첨가량이 증가할수록 수용성 단백질 함량도 증가하였고, 환원당 함량은 도토리 분말 무첨가군에서 가장 높았고, 도토리 분말 첨가량이 증가할수록 환원당 함량은 감소하였다. 총 폴리페놀 및 플라보노이드 함량은 도토리 분말 20%첨가 설기떡에서 가장 높았고 각각 1.91, 2.49 mg/g이었다. 관능검사 결과, 색은 도토리 분말 15% 첨가군이 가장 기호도가 높았고, 맛과 향, 질감, 전반적인 기호도에서는 도토리 분말 10% 첨가군에서 가장 높았으며, 그 다음으로 도토리 분말 15% > 5%> 0% > 20% 순으로 평가되었다.
2. 도토리 설기떡의 저장기간에 따른 품질특성을 분석한 결과 수분함량의 변화는 40.15~45.80%으로 도토리 분말의 첨가량이 증가할수록 다소 수분함량은 높았으나 큰 차이를 보이지 않았다. 색도변화에서는 L값은 54.13~36.33으로 도토리 분말 첨가량이 증가할수록 명도값이 감소하였고, a값과 b값은 도토리 분말을 첨가할수록 증가하였다. 조직감 측정 결과, 경도 및 부착성, 응집성, 씹힘성은 도토리 분말 첨가량이 증가할수록 저장기간이 길어질수록 감소함을 보였다. 총균수는 저장 초기 도토리 분말을 첨가하지 않은 무첨가구는 4.68×104 CFU/g이었고, 도토리 분말을 첨가한 설기떡의 총균수는 4.43~4.69×104 CFU/g으로 도토리 분말의 첨가량이 많을수록 총균수는 다소 낮았으며, 저장기간이 길어질수록 총균수는 모든군에서 다소 증가함을 보였고, 도토리 분말의 첨가량이 많을수록 총균수는 낮았다.
3. 도토리 설기떡 열수 및 에탄올 추출물의 항산화 활성 결과 수율은 열수 추출물이 에탄올 추출물에 비해 다소 높았고, 도토리 분말의 첨가량이 증가할수록 증가하였다. ABTS 라디칼 소거활성 결과 열수 및 에탄올 추출물의 농도가 증가함에 따라 ABTS 라디칼 소거활성은 증가함을 보였고, 1,000 μg/mL 농도에서는 도토리 분말 20% 첨가 설기떡 열수 및 에탄올 추출물이 각각 53.63, 65.98%로 가장 높았다. 전자공여능 측정 결과 도토리 분말의 첨가량이 증가할수록 모든 설기떡의 농도에서 전자공여능은 증가하였고, 1,000 μg/mL 농도에서는 도토리 분말 10%첨가 이상의 설기떡의 열수 추출물과 도토리 분말 15% 첨가 이상의 설기떡 에탄올 추출물에서는 50% 이상의 전자공여능을 보였다. SOD 유사활성 측정에서는 도토리 설기떡 열수 및 에탄올 추출물의 농도가 증가함에 따라 SOD 유사활성은 다소 증가함을 보였고, 아질산염 소거능 측정 결과 pH 1.2와 3.0에서 추출물의 농도에 따른 아질산염 소거능 차이는 크게 나타나지 않았다. Tyrosinase 저해효과 측정 결과 도토리 설기떡 모든 열수 추출물 62.5 μg/mL 농도에서는 14.61~21.79%로 대조구인 ascorbic acid보다 높았으며, 125 μg/ mL 농도에서도 모든 도토리 설기떡 열수 추출물에서 대조구에 비해 높았다. 환원력 측정 결과에서는 도토리 설기떡 추출물의 농도가 증가함에 따라 환원력은 증가함을 보였고, 도토리 분말 20% 첨가 설기떡의 열수 및 에탄올 추출물은 1,000 μg/ mL의 농도에서 각각 0.18, 0.23의 환원력을 보여 다른 추출물에 비해 환원력이 높았다.
이상의 결과에서 도토리 분말의 첨가량을 달리하여 제조한 도토리 설기떡은 항산화 물질의 대표적인 폴리페놀 및 플라보노이드 물질도 함유하고 있었고, 도토리 설기떡 열수 및 에탄올 추출물의 항산화성도 우수한 활성을 보여 다양한 기능성 식품소재 개발 및 식품으로써 활용 가치가 충분히 있을 것으로 생각된다.

This study tried to utilize the acorn as a baseline material for increasing its utilization as food material along with enhancing the functionality of acorn Sulgidduk(steamed rice cake) through the research on the physiochemical property of acorn Sulgidduk, quality property according to the storage period and the antioxidant effect, etc. of hydrothermal and ethanol extracts of the acorn Sulgidduk after manufacturing the acorn Sulgidduk with different addition rates of acorn powder by 0, 5, 10, 15 and 20% in comparison with those of the rice flour by using the acorn having various and superior pharmaceutical activation.
1. As a result of analyzing physiochemical properties of acorn Sulgidduk, the moisture content of general component was 40.15~44.42%, and it was shown that the moisture content was increased as the amount of added acorn powder was increased, and the contents of carbohydrate and crude protein were decreased as the amount of added acorn powder was increased, and the contents of crude fat and crude ash were increased as the amount of added acorn powder was increased. pH was 2.54~5.61, and it was shown that this was lowered as the amount of added acorn powder was increased. Sugar content was 1.17~1.74 °Brix, and although it was shown to have a tendency that this was somewhat lowered as the amount of added acorn powder was increased, but there was no significant difference. The content of water soluble protein was 0.10~0.81 g/100 g, and compared with the group to which no acorn powder was added, the content of water soluble protein was increased as the amount of added acorn powder was increased also, and the content of reduced sugar was highest in the group to which no acorn powder was added, and the content of reduced sugar was decreased as the amount of added acorn powder was increased. Contents of total polyphenol and flavonoid were highest in the Sulgidduk to which 20% of the acorn powder was added, and they were 1.91 and 2.49 mg/gm respectively. As a result of the sensory test, the preference for color was highest in the group to which 15% of acorn powder was added, and the preference for taste, flavor, texture and overall aspects was highest in the group to which 10% of acorn powder was added acorn powder, and it was evaluated in the order of 15% > 5%> 0% > 20%.
2. As a result of analyzing the quality property according to the storage period of acorn Sulgidduk, the change in moisture content was 40.15~45.80%, and no big difference was shown although the moisture content was somewhat high as the amount of added acorn powder was increased. In the chromaticity change, L value was 54.13~36.33, and the brightness value was decreased as the amount of added acorn powder was increased, and a value and b value were increased as acorn powders were added. As a result of measuring the texture, the hardness, adherence, cohesiveness and chewiness were shown to be decreased as the amount of added acorn powder was increased and as the storage period was longer. Total cell number for the group to which no acorn powder was added at the early stage of storage was 4.68×104 CFU/g, and the total cell number of Sulgidduk where acorn powders were added was 4.43~4.69×104 CFU/g, and the total cell number was somewhat low as the amount of added acorn powder was increased. It was shown that the total cell number was somewhat increased in all of the groups as the storage period was longer, and the total cell number was low as added acorn powders were large in quantity.
3. As a result of antioxidant activity of hydrothermal and ethanol extracts of acorn Sulgidduk, the yield was somewhat higher for hydrothermal extract compared with that for ethanol extract, and the yield was increased as the amount of added acorn powder was increased. As a result of ABTS radical scavenging activity, it was shown that the ABTS radical scavenging activity was increased as the concentration of hydrothermal and ethanol extracts was increased. And at the concentration of 1,000 μg/mL, hydrothermal and ethanol extracts of the Sulgidduk to which 20% of acorn powder was added were shown the highest ABTS radical scavenging activity with the percentage of 53.63 and 65.98%, respectively. As a result of measuring the electron donating ability, electron donating abilities were increased at all of the Sulgidduk concentrations as the amount of added acorn powder was increased, and at the concentration of 1,000 μg/mL, higher than 50% of electron donating ability was shown in the hydrothermal extract of Sulgidduk to which more than 10% of acorn powder was added and the ethanol extract of Sulgidduk to which more than 15% of acorn powder was added. In the measurement of SOD-like activity, it was shown that the SOD-like activity was somewhat increased as the concentration of hydrothermal and ethanol extracts of acorn Sulgidduk was increased. As a result of measuring the nitrite scavenging ability, the big difference in nitrite scavenging ability according to the concentration of extract at pH 1.2 and 3.0 was not shown. As a result of measuring the inhibition effect of tyrosinase, it was 14.61~21.79% at the concentration of 62.5 μg/mL for all of the hydrothermal extracts of acorn Sulgidduk, and it was higher than 2.50% for ascorbic acid which was the control group, and at the concentration of 125 μg/mL, it was higher in comparison with that for the control group in all of the hydrothermal extracts of acorn Sulgidduk, and somewhat higher compared with that for the ethanol extract. As a result of measuring the reducing power, it was shown that the reducing power was increased as the concentration of acorn Sulgidduk extract was increased, and the hydrothermal and ethanol extracts of Sulgidduk to which 20% of acorn powder was added showed reducing powers of 0.18 and 0.23 at the concentration of 1,000 μg/mL, respectively, and therefore, it was shown that the reducing power was increased as the amount of added acorn powder was larg