부지화와 세토카 감귤의 유리당· 유기산·플라보노이드 분석 및 정유의 생리활성 연구

Abstract

고품질 만감류인 부지화와 세토카의 유리당, 유기산, 플라노이드 성분을 분석하고, 에센셜 오일의 항산화 및 항균 활성 확인을 통해 기능성 소재 가능성을 검토하였다. 부지화와 세토카 과즙의 유리당 함량을 분석한 결과, 각각 11.8%, 11.5%로 서로 비슷한 수준을 나타내었고, 유기산 함량은 각각 1.31%, 1.68%로 세토카가 더 높은 농도를 나타내었다. 그리고 이를 기초로 환산한 당산비는 부지화가 8.7, 세토카가 7.0으로 부지화가 더 높은 수준을 나타내었다. 과육과 과피의 플라보노이드 함량을 분석한 결과, 총플라보노이드는 두 품종 모두 과육보다 과피에서 더 높았고, 부지화보다는 세토카에서 1g 당 54.28 mg Naringin으로 더 높은 함량을 나타내었다. 주요 플라보노이드 성분은 narirutin과 hesperidin이었으며, 대체적으로 두 성분의 합이 총플라보노이드와 유사한 값을 나타내었다. 부지화와 세토카 감귤의 미숙과 및 완숙과 껍질에서 추출한 에센셜 오일의 주요 성분은 dl-limonene, sabinene, linalool, 4-terpineol 등으로 확인되었고, 이들 중 limonene의 함량이 75% 이상으로 가장 높았다. 에센셜 오일의 항산화능을 측정한 결과, 부지화 감귤의 SC50 값은 완숙과에서 65.5 μL/mL, 미숙과에서 36.1 μL/mL이었고, 세토카의 SC50 값은 완숙과 40.3 μL/mL, 미숙과 35.3 μL/mL로 두 품종 모두 완숙과보다는 미숙과 껍질의 활성이 더 우수한 것으로 조사되었다. 또한 에센셜 오일의 항균활성을 조사해 본 결과, 전체적으로 활성을 보였고 특히 내성균주에 대한 항균력이 큰 것으로 확인되었다.

This study has aimed to analyze the free sugars, organic acids, and flavonoids of Shiranuhi and Setoka citrus fruits among high quality Citrus hybrids which have recently shown an increased consumption, and examine the possibility of new functional materials according to the verification of anti-oxidant and anti-microbial activities using essential oils. The analytical result of free sugar and organic acid contents in diluted juice of Shiranuhi and Setoka citrus fruits showed they had similar free sugar contents as 11.8% and 11.5% respectively, whereas Setoka had higher free acid content than Citrus Shiranuhi as 1.68%>1.31%. However, according to the comparison between soluble solid-acid ratios, which are regarded as an index of palatability of citrus oranges, Citrus Shiranuhi showed a higher ratio than Setoka, that is 8.7 and 7.0, respectively. By way of drying and grinding the flesh and peel without fruit juice, 70% MeOH was extracted, and then the flavonoid contents were analyzed. As a result, for both citrus cultivars, the total flavonoid content was higher in flesh than in peel. However the total flavonoid content in Setoka was higher than in Citrus Shiranuhi. Particularly, the flavonoid content in Setoka peel was considerably high as 54.28 mg naringin/g. Qualitative and quantitative analysis of each extract indicated that the main flavonoids were narirutin and hesperidin, and showed these two flavonoids occupied most of the total flavonoid content. Using Essential Oil Determination Apparatus, the essential oils were extracted from the peels of immature and mature citrus fruits of Shiranuhi and Setoka. The GC-MS analysis of ingredients in each oil showed that main ingredients were dl-limonene, sabinene, linalool and 4-terpineol, and the content of limonene was the highest as 75%. According to DPPH radical scavenging experiment for each oil, SC50 values of Citrus Shiranuhi were quite low as 65.5 ?L/mL for mature fruits and 36.1 ?L/mL for immature ones, showing good anti-oxidizing activity, compared to that of vitamin C as a control group, 6.9 ?g/mL. Moreover, for SC50 values of Setoka, immature fruits showed better activity as 35.3 ?L/mL. In order to examine anti-microbial activities for essential oils, the paper disc method and MIC were conducted on P. acnes and S. epidermidis as skin-related microorganisms. As a result, they generally showed anti-microbial activities, particularly for resistant bacteria. In conclusion, the results of this study suggested the development possibility of functional products and acne-related products by using peel extracts and essential oils from high-quality citrus fruits, more specifically, Citrus Shiranuhi and Setoka.